VNS Message Board

VNS DISCUSSIONS => Legislative Activism In Regards to VNS => Topic started by: dennis100 on March 23, 2012, 08:32:38 AM



Title: Short Circuit
Post by: dennis100 on March 23, 2012, 08:32:38 AM
Model Number 302-30
Event Date 07/28/2009
Event Type Malfunction
Event Description
It was reported that a patient experienced pain and would grab the electrode and generator site every time the device activated stimulation. Further information was received from the medical professional stating that the patient's dc dc code dropped from 2 to 0 on system diagnostics. Additionally, the patient experienced an increase in seizures below pre-vns baseline which have not resolved by an increase in settings like they have done in the past. Based on clinical symptoms and the diagnostic history of the patient's device, the issue is possibly related to a short-circuit condition.

http://www.accessdata.fda.gov/scripts/cdrh/cfdocs/cfMAUDE/detail.cfm?mdrfoi__id=1491972


Title: Re: Short circuit
Post by: dennis100 on March 23, 2012, 08:32:57 AM
Model Number 302-20
Event Date 05/01/2004
Event Type Malfunction
Event Description
As part of a retrospective complaint review associated with an investigation of low impedance events, the events in this complaint investigation were assessed for the possibility of a short-circuit condition in the implanted lead. Based on clinical symptoms and the diagnostic history of the pt's device, this file was found to be possibly related to a short-circuit condition. It was reported that a vns pt was experiencing events of painful stimulation with neck rotation. Follow up with the pt's treating vns therapy physician revealed that a decrease in the pt's therapy settings had not resolved the issue through the symptoms had improved.

http://www.accessdata.fda.gov/scripts/cdrh/cfdocs/cfMAUDE/detail.cfm?mdrfoi__id=1492068


Title: Re: Short circuit
Post by: dennis100 on March 23, 2012, 08:33:20 AM
Model Number 300-20
Event Date 11/16/2007
Event Type Malfunction
Event Description
During review of diagnostic history, this patient was identified to have an impedance value at the date of generator replacement surgery of 583 ohms. This is vastly lower than expected and suggests that this patient may have a short-circuit condition within the lead. Follow-up with the physician reveals that the patient has experienced an increase in seizures and does not feel stimulation. Attempts for additional information have been unsuccessful to date.

Manufacturer Narrative
Device failure is suspected.

http://www.accessdata.fda.gov/scripts/cdrh/cfdocs/cfMAUDE/detail.cfm?mdrfoi__id=1492069


Title: Re: Short circuit
Post by: dennis100 on March 23, 2012, 08:34:01 AM
Model Number 302-20
Event Date 05/01/2004
Event Type Malfunction
Event Description
As part of a retrospective complaint review associated with an investigation of low impedance events, the events in this complaint investigation were assessed for the possibility of a short-circuit condition in the implanted lead. Based on clinical symptoms and the diagnostic history of the patient's device, this file was found to be possibly related to a short-circuit condition. It was reported to manufacturer by the vns patient that the stimulation of the device did not feel as strong as it had previously, and that she had a recent increase in seizure activity as well as tooth pain. The patient further explained that she was involved in a physical altercation where she had been attacked and injured. The patient had been to see her neurologist following the incident, however, the altercation and subsequent adverse events that followed were not mentioned to the physician.

Manufacturer Narrative
Device failure is suspected, but did not cause or contribute to death or serious injury.

http://www.accessdata.fda.gov/scripts/cdrh/cfdocs/cfMAUDE/detail.cfm?mdrfoi__id=1492071


Title: Re: Short circuit
Post by: dennis100 on March 23, 2012, 08:34:20 AM
Model Number 302-20
Event Date 07/01/2009
Event Type Malfunction
Event Description
Initial reporter indicated to a manufacturing consultant that their pt was having an increase in their seizures over their pre vns seizure rate and their dcdc code on their systems test had gone from a dcdc 2 to dcdc 0. The pt has not had any fall or injury preceding the dcdc 0. At this time unk cause of the pt's increase in seizures is related to the pt's dcdc 0. The pt's medications were titrated and the pt will be scheduled for a prophylactic generator replacement before it reaches end of battery life. The lead will be evaluated in the or for a possible short circuit condition.

http://www.accessdata.fda.gov/scripts/cdrh/cfdocs/cfMAUDE/detail.cfm?mdrfoi__id=1493827


Title: Re: Short circuit
Post by: dennis100 on March 23, 2012, 08:34:47 AM
Model Number 300-20
Event Date 07/13/2004
Event Type Malfunction
Manufacturer Narrative
Device failure is suspected, but did not cause or contribute to a death or serious injury.

Event Description
As part of a retrospective complaint review associated with an investigation of low impedance events, the events in this complaint investigation were assessed for the possibility of a short-circuit condition in the implanted lead. Based on clinical symptoms and the diagnostic history of the patient's device, this file was found to be possibly related to a short-circuit condition. It was reported that vns patient's seizure duration has increased. It is unknown if interventions were taken for this event. The patient's neurologist determined that the event was related to an "oil" the patient was given for constipation, therefore, unrelated to vns therapy. If present, an intermittent short-circuit could have potentially contributed to the patient's increased seizure duration event

http://www.accessdata.fda.gov/scripts/cdrh/cfdocs/cfMAUDE/detail.cfm?mdrfoi__id=1492059


Title: Re: Short circuit
Post by: dennis100 on March 23, 2012, 08:35:38 AM
Model Number 300-20
Event Date 01/25/2005
Event Type Malfunction
Manufacturer Narrative
Results: x-rays reviewed by the manufacturer, no gross lead discontinuities visualized. Conclusion : device failure occurred, but did not cause or contribute to a death or serious injury.

Event Description
As part of a retrospective complaint review associated with an investigation of low impedance events, the events in this complaint investigation were assessed for the possibility of a short-circuit condition in the implanted lead. Based on clinical symptoms and the diagnostic history of the patient's device, this file was found to be possibly related to a short-circuit condition. It was reported that the vns patient experienced erratic stimulation following end-of-service generator replacement surgery. It was also indicated that the patient experienced migraine headaches and pain in the throat with stimulation. Review of x-ray views of the device did not reveal any obvious anomalies that could have contributed to the reported erratic stimulation event. The patient's device was replaced for erratic stimulation. The explanted products were returned to the manufacturer for product analysis. Product analysis has been completed on the lead portion. Based on the findings, there is no evidence to suggest a discontinuity in the lead which may have contributed to the reported allegation. Note that since the electrode array section was not returned for analysis, an evaluation and resulting commentary cannot be made on that portion of the lead. Abrasions in the insulation of the inner tubing were visualized during analysis of the lead. This condition could potentially have an impact with the intended delivery of stimulation. If present, an intermittent short-circuit could have potentially contributed to the patient's erratic stimulation, migraine headaches and pain in the throat events.

http://www.accessdata.fda.gov/scripts/cdrh/cfdocs/cfMAUDE/detail.cfm?mdrfoi__id=1492060


Title: Re: Short circuit
Post by: dennis100 on March 23, 2012, 08:36:09 AM
Model Number 302-30
Event Date 11/21/2002
Event Type Malfunction
Event Description
As part of a retrospective complaint review associated with an investigation of low impedance events, the events in this complaint investigation were assessed for the possibility of a short-circuit condition in the implanted lead. Based on clinical symptoms and the diagnostic history of the pt's device, this file was found to be possibly related to a short-circuit condition. It was reported that a vns pt was unable to perceive stimulation after her initial implant surgery, even with the device programmed to maximum settings. The pt's implanting surgeon also stated that he was concerned by the fact that the pt did not experience any events of voice alterations at these settings as well. System and normal mode diagnostics were performed repeatedly and each test resulted in a dcdc code of zero. X-rays of the pt's device were reviewed by her surgeon and no anomalies were reportedly identified. Later the pt underwent exploratory surgery, during which the electrode portions of the pt's lead were repositioned on her vagus nerve. Follow up with the pt's implanting surgeon revealed that the pt was able to perceive stimulation following electrode repositioning.

Manufacturer Narrative
Implanting surgeon reviewed x-rays of implanted device. X-rays reviewed by the implanting surgeon, no gross lead discontinuities visualized.

http://www.accessdata.fda.gov/scripts/cdrh/cfdocs/cfMAUDE/detail.cfm?mdrfoi__id=1492063


Title: Re: Short circuit
Post by: dennis100 on March 23, 2012, 08:36:33 AM
Model Number 302-20
Event Date 05/01/2004
Event Type Malfunction
Event Description
As part of a retrospective complaint review associated with an investigation of low impedance events, the events in this complaint investigation were assessed for the possibility of a short-circuit condition in the implanted lead. Based on clinical symptoms and the diagnostic history of the pt's device, this file was found to be possibly related to a short-circuit condition. It was reported that a vns pt was experiencing events of painful stimulation with neck rotation. Follow up with the pt's treating vns therapy physician revealed that a decrease in the pt's therapy settings had not resolved the issue through the symptoms had improved.

http://www.accessdata.fda.gov/scripts/cdrh/cfdocs/cfMAUDE/detail.cfm?mdrfoi__id=1492064


Title: Re: Short circuit
Post by: dennis100 on March 23, 2012, 08:37:04 AM
Model Number 300-30
Event Date 07/11/2004
Event Type Malfunction
Event Description
As part of a retrospective complaint review associated with an investigation of low impedance events, the events in this complaint investigation were assessed for the possibility of a short-circuit condition in the implanted lead. Based on clinical symptoms and the diagnostic history of the patient's device, this file was found to be possibly related to a short-circuit condition. It was reported to manufacturer that the vns patient presented at the er on (b) (6) 2004 with severe neck pain with stimulation of the vns device. Both normal mode and system diagnostic tests were performed on that date, and revealed normal device function. The er physician decreased the pulse width setting from 500usec to 250usec, and the pain improved.

Manufacturer Narrative
Device failure is suspected, but did not cause or contribute to death or serious injury.

http://www.accessdata.fda.gov/scripts/cdrh/cfdocs/cfMAUDE/detail.cfm?mdrfoi__id=1492072


Title: Re: Short circuit
Post by: dennis100 on March 23, 2012, 08:37:28 AM
Model Number 302-20
Event Date 07/24/2009
Event Type Malfunction
Event Description
Reporter indicated a vns pt had a systems diagnostics dcdc code result of 0. The pt previously had dcdc codes of 1 and 2. The pt has also been experiencing painful stimulation at the neck and generator sites. The reporter suspects a possible short-circuit condition with the vns lead. The vns has been disabled and vns revision surgery is likely, but a surgery date has not been set.

Manufacturer Narrative
Device failure is suspected, but did not cause or contribute to a death or serious injury.

http://www.accessdata.fda.gov/scripts/cdrh/cfdocs/cfMAUDE/detail.cfm?mdrfoi__id=1490567


Title: Re: Short circuit
Post by: dennis100 on March 23, 2012, 08:37:59 AM
Model


Title: Re: Short circuit
Post by: dennis100 on March 23, 2012, 08:38:28 AM
Model Number 302-30
Device Problem Low impedance
Event Date 01/01/2006
Event Type Malfunction
Event Description
As part of a retrospective complainant review associated with an investigation of low impedance events, the events in this complaint investigation were assessed for the possibility of a short-circuit condition in the implanted lead. Based on clinical symptoms and the diagnostic history of the pt's device, this file was found to be possibly related to a short-circuit condition. It was reported that the vns pt was experiencing increase in seizures, not above pre-vns baseline. Pt was also complaining about blurred vision, headache and dizziness. However, current information may suggest a possible relationship to the short-circuit condition of the implanted lead.

Manufacturer Narrative
Device failure is suspected, but did not cause or contributed to a death or serious injury.

http://www.accessdata.fda.gov/scripts/cdrh/cfdocs/cfMAUDE/detail.cfm?mdrfoi__id=1477520


Title: Re: Short circuit
Post by: dennis100 on March 23, 2012, 08:39:03 AM
Model Number 300-20
Device Problems Low impedance; Electrical shorting
Event Date 01/01/2006
Event Type Malfunction
Event Description
As part of a retrospective complaint review associated with an investigation of low impedance events, the events in this complaint investigation were assessed for the possibility of a short-circuit condition in the implanted lead. Based on clinical symptoms and the diagnostic history of the pt's device, this file was found to be possibly related to a short-circuit condition. It was reported that the vns pt was experiencing pain in the base of the neck that radiates through the left side of the face and to the apex of the head. Pain was related to stimulation. Pain was resolved with change in parameters. However, current info may suggest a possible relationship to the short-circuit condition of the implanted lead.

Manufacturer Narrative
Device failure is suspected, but did not cause or contribute to a death or serious injury.

http://www.accessdata.fda.gov/scripts/cdrh/cfdocs/cfMAUDE/detail.cfm?mdrfoi__id=1477521


Title: Re: Short circuit
Post by: dennis100 on March 23, 2012, 08:39:35 AM
Model Number 300-20
Event Date 01/01/2006
Event Type Malfunction
Event Description
As part of a retrospective complaint review associated with an investigation of low impedance events, the events in this complaint investigation were assessed for the possibility of a short-circuit condition in the implanted lead. Based on clinical symptoms and the diagnostic history of the pt's device, this file was found to be possibly related to a short-circuit condition. It was reported to the mfr that the vns pt was seen by the treating physician for a follow up visit due to an increase in seizure activity, below the pre-vns baseline, and the pt was no longer feeling normal delivery of stimulation. The pt subsequently had the generator replaced. The explanted generator was returned to manufacturer, where analysis confirmed proper generator function.

Manufacturer Narrative
Device malfunction is suspected but did not cause or contribute to a death or serious injury.

http://www.accessdata.fda.gov/scripts/cdrh/cfdocs/cfMAUDE/detail.cfm?mdrfoi__id=1477522


Title: Re: Short circuit
Post by: dennis100 on March 23, 2012, 08:40:03 AM
Model Number 302-20
Event Date 01/01/2006
Event Type Malfunction
Manufacturer Narrative
Device malfunction is suspected but did not cause or contribute to a death.

Event Description
As part of a retrospective complaint review associated with an investigation of low impedance events, the events in this complaint investigation were assessed for the possibility of a short-circuit condition in the implanted lead. Based on clinical symptoms and the diagnostic history of the pt's device, this file was found to be possibly related to a short-circuit condition. It was reported the pt began experiencing an increase in seizures and could not feel magnet or normal mode stimulation. The treating physician performed a system diagnostic test at a follow up appointment following the onset of the events, which revealed a dcdc code of "0", and the eos status was set to no. The pt subsequently underwent surgery where the generator was replaced. The explanted generator was not returned to mfr for analysis. Follow up with the treating physician has been unsuccessful regarding the status of the pt after re-implant.

http://www.accessdata.fda.gov/scripts/cdrh/cfdocs/cfMAUDE/detail.cfm?mdrfoi__id=1477523


Title: Re: Short circuit
Post by: dennis100 on March 23, 2012, 08:40:39 AM
Model Number 300-20
Device Problem Circuit Failure
Event Date 11/01/2006
Event Type Malfunction
Manufacturer Narrative
Device malfunction is suspected but did not cause or contribute to a death.

Event Description
As part of a retrospective complaint review associated with an investigation of low impedance events, the events in this complaint investigation were assessed for the possibility of a short-circuit condition in the implanted lead. Based on clinical symptoms and the diagnostic history of the pt's device, this file was found to be possibly related to a short circuit condition. It was reported to the manufacturer that the vns pt presented at the treating physician's office with an increase in breakthrough seizures, relationship to pre-vns baseline unk. No intervention was reported to have been taken. A system diagnostic test performed following the onset or the increase in seizures revealed a dcdc code of "0", and the end of service status was set to no.

http://www.accessdata.fda.gov/scripts/cdrh/cfdocs/cfMAUDE/detail.cfm?mdrfoi__id=1477524


Title: Re: Short circuit
Post by: dennis100 on March 23, 2012, 08:41:14 AM
Model Number 302-20
Event Date 12/01/2006
Event Type Malfunction
Event Description
As part of a retrospective complaint review associated with an investigation of low impedances events, the events in this complaint investigation were assessed for the possibility of a short-circuit condition in the implanted lead. Based on clinical symptoms and the diagnostic history of the pt's device, this file was found to be possibly related to a short-circuit condition. It was reported to manufacturer that the vns pt had a major fall and following the fall, the pt could no longer tolerate stimulation due to painful stimulation, feeling that the device was constantly stimulating at times, and experiencing severe coughing during stimulation. System diagnostics performed following the fall revealed a dcdc code of "0", and end of service status was set to no. X-rays were sent to manufacturer to review, and there were no lead discontinuities identified. The physician opted to disable the device as intervention, and the adverse events resolved. The device remains off and still implanted in the pt.

Manufacturer Narrative
Manufacturer reviewed x-rays of implanted device. X-rays reviewed by the manufacturer, no gross lead discontinuities visualized. Device malfunction is suspected but did not cause or contribute to a death.

http://www.accessdata.fda.gov/scripts/cdrh/cfdocs/cfMAUDE/detail.cfm?mdrfoi__id=1477525


Title: Re: Short circuit
Post by: dennis100 on March 23, 2012, 08:41:51 AM
Model Number 300-20
Event Date 01/01/2006
Event Type Malfunction
Manufacturer Narrative
Device malfunction is suspected, but did not cause or contribute to death or serious injury.

Event Description
As part of a retrospective complaint review associated with an investigation of low impedance events, the events in this complaint investigation were assessed for the possibility of a short-circuit condition in the implanted lead. Based on clinical symptoms and the diagnostic history of the pt's device, this file was found to be possible related to a short-circuit condition. It was reported that the vns pt had been experiencing a gradual increase in voice alteration and throat discomfort with stimulation. There had been no recent setting changes or trauma that could have contributed to the events. The pt was seen by the physician following the onset of the reported events where the device settings were altered to help with the discomfort. The pt was tolerating the setting changes well and the discomfort had immediately improved. Diagnostic testing was performed which revealed a system diagnostic dcdc code of "0" and a normal mode dcdc code of "1".

http://www.accessdata.fda.gov/scripts/cdrh/cfdocs/cfMAUDE/detail.cfm?mdrfoi__id=1477527


Title: Re: Short circuit
Post by: dennis100 on March 23, 2012, 08:42:32 AM
Model Number 302-20
Device Problem Low impedance
Event Date 01/01/2007
Event Type Malfunction
Event Description
As part of a retrospective complaint review associated with an investigation of low impedance events, the events in this complaint investigation were assessed for the possibility of a short-circuit condition in the implanted lead. Based on clinical symptoms and the diagnostic history of the pt's device, this file was found to be possibly related to a short-circuit condition. It was reported to mfr by the vns pt's caregiver, that the pt began experiencing increased coughing and choking sensation during stimulation of the device. According to the reporter, there had been no recent programmed setting changes, trauma, or manipulation of the device that could be contributing to the onset of the events. The pt was seen by the treating physician due to the coughing and dysphagia events, and the vns device output setting were decreased to help with the events. A system diagnostic test was performed at this office visit and revealed a dcdc code of "0". The setting change improved the coughing and dysphagia temporarily, until several weeks later, the events continued, again with no reports of trauma or manipulation. The device was temporarily disabled where the events resolved. The device settings were programmed back on shortly thereafter as the pt was receiving efficacy for their seizure disorder. Good faith attempts to obtain additional info from the treating physician have been made, but have been unsuccessful to date.

Manufacturer Narrative
Device malfunction is suspected, but did not cause or contribute to a death or serious injury.

http://www.accessdata.fda.gov/scripts/cdrh/cfdocs/cfMAUDE/detail.cfm?mdrfoi__id=1477528


Title: Re: Short circuit
Post by: dennis100 on March 23, 2012, 08:43:09 AM
Model Number 302-20
Event Date 01/01/2006
Event Type Malfunction
Event Description
As part of a retrospective complaint review associated with an investigation of low impedance events, the events in this complaint investigation were assessed for the possibility of a short-circuit condition in the implanted lead. Based on clinical symptoms and the diagnostic history of the pt's device, this file was found to be possibly related to a short-circuit condition. It was initially reported by a pt's mother that her daughter was experiencing an increase in seizures and she thought the device may be nearing eos. F/u with the physician's office revealed that the pt's seizures were not above pre-vns baseline, and that they did not think it was an increase. It was additionally reported that diagnostics were performed in (b) (6) 2007, showing proper device function. Nurse indicated that pt was given a new medication to try, but that they had not heard back from the mother since the (b) (6) appointment.

Manufacturer Narrative
Device failure is suspected, but did not cause or contribute to a death or serious injury.

http://www.accessdata.fda.gov/scripts/cdrh/cfdocs/cfMAUDE/detail.cfm?mdrfoi__id=1476454


Title: Re: Short circuit
Post by: dennis100 on March 23, 2012, 08:43:38 AM
Model Number 300-20
Event Date 01/01/2007
Event Type Malfunction
Event Description
As part of a retrospective complaint review associated with an investigation of low impedance events, the events in this complaint investigation were assessed for the possibility of a short-circuit condition in the implanted lead. Based on clinical symptoms and the diagnostic history of the pt's device, this file was found to be possibly related to a short-circuit condition. It was reported that the pt experienced an increase in seizures below pre-vns baseline. A battery life calculation with sufficient programming history estimated over 2 yrs remaining and during diagnostic testing the eri-no. System and normal mode diagnostics were within normal limits, indicating proper device function. The treating physician did not indicate a cause for the increase in seizures, but the duty cycle was increased.

Manufacturer Narrative
Device failure is suspected, but did not cause or contribute to a death or serious injury.

http://www.accessdata.fda.gov/scripts/cdrh/cfdocs/cfMAUDE/detail.cfm?mdrfoi__id=1476455


Title: Re: Short circuit
Post by: dennis100 on March 23, 2012, 08:44:13 AM
Model Number 302-20
Event Date 05/29/2008
Event Type Malfunction
Manufacturer Narrative
Device failure is suspected, but did not cause or contribute to a death or serious injury.

Event Description
As part of a retrospective complaint review associated with an investigation of low impedance events, the events in this complaint investigation were assessed for the possibility of a short-circuit condition in the implanted lead. Based on clinical symptoms and the diagnostic history of the pt's device, this file was found to be possibly related to a short-circuit condition. It was reported that a vns pt was not able to perceive stimulation after being re-implanted with a new generator. Add'l info received from the neurologist indicated that stimulation was present at some point and now the pt was not able to feel either normal or magnet mode stimulation. Diagnostic results were within normal limits, however, current info may suggest a possible relationship to the short-circuit condition of the implanted lead.

http://www.accessdata.fda.gov/scripts/cdrh/cfdocs/cfMAUDE/detail.cfm?mdrfoi__id=1476460


Title: Re: Short circuit
Post by: dennis100 on March 23, 2012, 08:44:48 AM
Model Number 302-20
Event Date 07/10/2008
Event Type Malfunction
Event Description
As part of a retrospective complaint review associated with an investigation of low impedance events, the events in this complaint investigation were assessed for the possibility of a short-circuit condition in the implanted lead. Based on clinical symptoms and the diagnostic history of the pt's device, this file was found to be possibly related to a short-circuit condition. It was reported that the vns pt experienced an increase in seizures. The treating nurse indicated the seizures were below pre-vns baseline and diagnostics were within normal limits. However, current info may suggest a possible relationship to the short-circuit condition of the implanted lead.

Manufacturer Narrative
Device failure is suspected, but did not cause or contribute to a death or serious injury.

http://www.accessdata.fda.gov/scripts/cdrh/cfdocs/cfMAUDE/detail.cfm?mdrfoi__id=1476463


Title: Re: Short circuit
Post by: dennis100 on March 23, 2012, 08:45:25 AM
Model Number 302-20
Event Date 06/26/2008
Event Type Malfunction
Event Description
As part of a retrospective complaint review associated with an investigation of low impedance events, the events in this complaint investigation were assessed for the possibility of a short-circuit condition in the implanted lead. Based on clinical symptoms and the diagnostic history of the pt's device, this file was found to be possibly related to a short-circuit condition. It was reported that a vns pt experienced painful stimulation in the neck area. Good faith attempts to obtain add'l info from the treating neurologist have been unsuccessful at the moment. However, current info may suggest a possible relationship to the short-circuit condition of the implanted lead.

Manufacturer Narrative
Device failure is suspected, but did not cause or contribute to a death or serious injury.

http://www.accessdata.fda.gov/scripts/cdrh/cfdocs/cfMAUDE/detail.cfm?mdrfoi__id=1476467


Title: Re: Short circuit
Post by: dennis100 on March 23, 2012, 08:45:55 AM
Model Number 300-20
Event Date 06/25/2008
Event Type Malfunction
Event Description
As part of a retrospective complaint review associated with an investigation of low impedance events, the events in this complaint investigation were assessed for the possibility of a short-circuit condition in the implanted lead. Based on clinical symptoms and the diagnostic history of the pt's device, this file was found to be possibly related to a short-circuit condition. It was reported that the vns pt experienced an increase in seizures. The treating nurse indicated the seizures were below pre-vns baseline. However, current info may suggest a possible relationship to the short-circuit condition of the implanted lead.

Manufacturer Narrative
Device failure is suspected, but did not cause or contribute to a death or serious injury.

http://www.accessdata.fda.gov/scripts/cdrh/cfdocs/cfMAUDE/detail.cfm?mdrfoi__id=1476468


Title: Re: Short circuit
Post by: dennis100 on March 23, 2012, 08:46:21 AM
Model Number 302-20
Event Date 06/09/2008
Event Type Malfunction
Manufacturer Narrative
Device failure is suspected, but did not cause or contribute to a death or serious injury.

Event Description
As part of a retrospective complaint review associated with an investigation of low impedance events, the events in this complaint investigation were assessed for the possibility of a short-circuit condition in the implanted lead. Based on clinical symptoms and the diagnostic history of the pt's device, this file was found to be possibly related to a short-circuit condition. It was reported that the vns pt experienced intermittent acute pain on the anterior left side of the neck. The treating physician stated the pain was likely related to implantation and unlikely related to stimulation. However, current info may suggest a possible relationship to the short-circuit condition of the implanted lead.

http://www.accessdata.fda.gov/scripts/cdrh/cfdocs/cfMAUDE/detail.cfm?mdrfoi__id=1476470


Title: Re: Short circuit
Post by: dennis100 on March 23, 2012, 08:46:53 AM
Model Number 302-20
Event Date 01/01/2008
Event Type Malfunction
Event Description
As part of a retrospective complaint review associated with an investigation of low impedance events, the events in this complaint investigation were assessed for the possibility of a short-circuit condition in the implanted lead. Based on clinical symptoms and the diagnostic history of the pt's device, this file was found to be possibly related to a short-circuit condition. It was reported that a vns pt experienced an increase in seizures that were above pre-vns baseline. Based on the clinical symptom and the diagnostic history of the pt's device, the neurologist stated the increase in seizures was related to low levels of therapeutic medicament and not related to vns therapy as the pt is doing well after medication was increased. However, current info may suggest a possible relationship to the short-circuit condition of the implanted lead.

Manufacturer Narrative
Device failure is suspected, but did not cause or contribute to a death or serious injury.

http://www.accessdata.fda.gov/scripts/cdrh/cfdocs/cfMAUDE/detail.cfm?mdrfoi__id=1476472


Title: Re: Short circuit
Post by: dennis100 on March 23, 2012, 08:47:23 AM
Model Number 300-20
Event Date 07/22/2008
Event Type Malfunction
Manufacturer Narrative
Mfr reviewed x-rays of implanted device. X-rays reviewed by the mfr, no gross lead discontinuities visualized. Device failure is suspected, but did not cause or contribute to a death or serious injury.

Event Description
As part of a retrospective complaint review associated with an investigation of low impedance events, the events in this complaint investigation were assessed for the possibility of a short-circuit condition in the implanted lead. Based on clinical symptoms and the diagnostic history of the pt's device, this file was found to be possibly related to a short-circuit condition. It was reported that a vns pt experienced neck pain with stimulation of the device. The magnet was placed over the generator and the pt was evaluated by the neurologist the following day. F/u from the neurologist revealed normal and system diagnostics to be within normal limits. The neurologist reduced the output current and the pt was relieved from neck pain. However, current info may suggest a possible relationship to the short-circuit condition of the implanted lead.

http://www.accessdata.fda.gov/scripts/cdrh/cfdocs/cfMAUDE/detail.cfm?mdrfoi__id=1476474


Title: Re: Short circuit
Post by: dennis100 on March 23, 2012, 08:47:56 AM
Model Number 302-20
Event Date 11/07/2008
Event Type Malfunction
Manufacturer Narrative
Device failure is suspected, but did not cause or contribute to a death or serious injury.

Event Description
As part of a retrospective complaint review associated with an investigation of low impedance events, the events in this complaint investigation were assessed for the possibility of a short-circuit condition in the implanted lead. Based on clinical symptoms and the diagnostic history of the pt's device, this file was found to be possibly related to a short-circuit condition. It was reported that a vns pt had experienced muscle spasms in the neck and throat during stimulation. No interventions were taken for these events. If present, an intermittent short-circuit could have potentially contributed to the pt's muscle spasms.

http://www.accessdata.fda.gov/scripts/cdrh/cfdocs/cfMAUDE/detail.cfm?mdrfoi__id=1476476


Title: Re: Short circuit
Post by: dennis100 on March 23, 2012, 08:48:24 AM
Model Number 302-20
Event Date 08/22/2008
Event Type Malfunction
Event Description
As part of a retrospective complaint review associated with an investigation of low impedance events, the events in this complaint investigation were assessed for the possibility of a short-circuit condition in the implanted lead. Based on clinical symptoms and the diagnostic history of the pt's device, this file was found to be possibly related to a short-circuit condition. It was reported that a vns pt did not experience any efficacy with vns therapy. Diagnostics performed on the device revealed proper device function. Review of programming history and confirmation with the physician revealed that multiple settings have been attempted to achieve greater efficacy. No interventions were taken for this event. If present, an intermittent short-circuit could have potentially contributed to the pt's lack of efficacy event.

Manufacturer Narrative
Device failure is suspected, but did not cause or contribute to a death or serious injury.

http://www.accessdata.fda.gov/scripts/cdrh/cfdocs/cfMAUDE/detail.cfm?mdrfoi__id=1476478


Title: Re: Short circuit
Post by: dennis100 on March 23, 2012, 08:48:49 AM
Model Number 302-20
Event Date 08/22/2008
Event Type Malfunction
Manufacturer Narrative
Device failure is suspected, but did not cause or contribute to a death or serious injury.

Event Description
As part of a retrospective complaint review associated with an investigation of low impedance events, the events in this complaint investigation were assessed for the possibility of a short-circuit condition in the implanted lead. Based on clinical symptoms and the diagnostic history of the pt's device, this file was found to be possibly related to a short-circuit condition. The pt's physician reported that the pt experienced an increase in seizures below pre-vns baseline due to possible battery depletion. Diagnostics performed on the device revealed proper device function. The pt's generator was replaced prophylactically and returned to the mfr for product analysis. Product analysis did not reveal any anomalies that may have contributed to the reported event. The end of service allegation was not duplicated in the product analysis laboratory. If present, an intermittent short-circuit could have potentially contributed to the pt's increased seizure activity, though this activity was still below pre-vns levels.

http://www.accessdata.fda.gov/scripts/cdrh/cfdocs/cfMAUDE/detail.cfm?mdrfoi__id=1476480


Title: Re: Short circuit
Post by: dennis100 on March 23, 2012, 08:49:14 AM
Model Number 300-20
Event Date 07/26/2006
Event Type Malfunction
Manufacturer Narrative
Device failure is suspected, but did not cause or contribute to a death or serious injury.

Event Description
Reporter indicated a pt could no longer feel vns stimulation and was also having increased seizures. All attempts for further info from the reporter were unsuccessful. The pt later underwent vns generator replacement and was still unable to feel vns stimulation. The explanted generator was returned for analysis. No anomalies were noted and the generator performed per specifications. As part of a retrospective complaint review associated with an investigation of low impedance events, the events in this complaint investigation were assessed for the possibility of a short-circuit condition in the implanted lead. Based on clinical symptoms and the diagnostic history of the pt's device. This file was found to be possibly related to a short-circuit condition.

http://www.accessdata.fda.gov/scripts/cdrh/cfdocs/cfMAUDE/detail.cfm?mdrfoi__id=1476488


Title: Re: Short circuit
Post by: dennis100 on March 23, 2012, 08:49:36 AM
Model Number 302-20
Event Date 07/04/2006
Event Type Malfunction
Manufacturer Narrative
Mfr reviewed x-rays of implanted device. X-rays reviewed by the mr, no gross lead discontinuities visualized. Conclusion code: device failure is suspected, but did not cause or contribute to a death or serious injury.

Event Description
Reporter indicated a vns pt experienced painful stimulation at the generator site along with muscle spasms in the left arm. X-rays were reviewed which did not identify any obvious lead discontinuities, but a sharp angle was noted in the lead near the lead/pin generator header interface. The pt underwent vns generator replacement surgery and the symptoms resolved. As part of a retrospective complaint review associated with an investigation of low impedance events, the events in this complaint investigation were assessed for the possibility of a short-circuit condition in the implanted lead. Based on clinical symptoms and the diagnostic history of the pt's device. This file was found to be possibly related to a short-circuit condition.

http://www.accessdata.fda.gov/scripts/cdrh/cfdocs/cfMAUDE/detail.cfm?mdrfoi__id=1476490


Title: Re: Short circuit
Post by: dennis100 on March 23, 2012, 08:50:02 AM
Model Number 302-30
Event Date 06/02/2006
Event Type Malfunction
Event Description
Reporter indicated: a pt had pain with vns stimulation at the generator site. Attempts to the reporter for further info were unsuccessful as the pt did not follow up with the reporter. As part of a retrospective complaint review associated with an investigation of low impedance events, the events in this complaint investigation were assessed for the possibility of a short-circuit condition in the implanted lead. Based on clinical symptoms and the diagnostic history of the pt's device, this file was found to be possibly related to a short-circuit condition.

Manufacturer Narrative
Device failure is suspected, but did not cause or contribute to a death or serious injury.

http://www.accessdata.fda.gov/scripts/cdrh/cfdocs/cfMAUDE/detail.cfm?mdrfoi__id=1476491


Title: Re: Short circuit
Post by: dennis100 on March 23, 2012, 08:50:25 AM
Model Number 300-20
Event Date 11/15/2005
Event Type Malfunction
Manufacturer Narrative
Device failure is suspected, but did not cause or contribute to a death or serious injury.

Event Description
Rptr indicated that a vns pt underwent vns lead and generator replacement surgery due to facial pain. The face pain reportedly resolved following replacement surgery. The explanted lead and generator were returned for analysis. Analysis of the generator did not reveal any anomalies and the generator performed per specifications. No anomalies were identified with the returned portions of the vns lead and therefore no findings that could have contributed to the facial pain complaint. Note that since part of the lead assembly (approx 50%) was not returned for analysis an eval and resulting commentary cannot be made on the portion of the lead. Other than typical wear and explanted related observations, there were no findings or anomalies noted on the returned portion of the lead. As part of a retrospective complaint review associated with an investigation of low impedance events, the events in this complaint investigation were assessed for the possibility of a short-circuit condition in the implanted lead. Based on clinical symptoms and the diagnostic history of the pt's device, this file was found to be possibly to a related a short-circuit condition.

http://www.accessdata.fda.gov/scripts/cdrh/cfdocs/cfMAUDE/detail.cfm?mdrfoi__id=1476493


Title: Re: Short circuit
Post by: dennis100 on March 23, 2012, 08:50:57 AM
Model Number 300-20
Device Problem No Information
Event Date 05/14/2009
Event Type Malfunction
Event Description
As a part of a retrospective complaint review associated with an investigation of low impedance events, the events in this complaint investigation were assessed for the possibility of a short-circuit condition in the implanted lead. Based on clinical symptoms and the diagnostic history of the patient's device, this file was found to be possibly related to a short-circuit condition. The reporter indicated that a vns patient had requested that his vns device be explanted as he felt that he had not received efficacy from therapy and added that his device had been programmed off for quite some time. A review of the patent's programming history revealed that the patient's generator was near end of service prior to device disablement. Good faith attempts to the patient's treating vns therapy physician assessment of the patient's lack of efficacy have been unsuccessful to date. Follow up with the patient's surgical facility revealed that the explanted device had been disposed of following surgery.

http://www.accessdata.fda.gov/scripts/cdrh/cfdocs/cfMAUDE/detail.cfm?mdrfoi__id=1476496


Title: Re: Short circuit
Post by: dennis100 on March 23, 2012, 08:51:20 AM
Model Number 302-20
Device Problem Low impedance
Event Date 03/13/2008
Event Type Malfunction
Manufacturer Narrative
Device failure is suspected.

Event Description
As part of a retrospective complaint review associated with an investigation of low impedance events, the events in this complaint investigation were assessed for the possibility of a short-circuit condition in the implanted lead. Based on clinical symptoms and the diagnostic history of the patient's device, this file was found to be possibly related to a short circuit condition. It was reported that a vns patient had experienced an increase in seizures, below pre-vns baseline levels, just prior to generator revision surgery. The patient's seizure activity reportedly began to decrease two days after revision surgery. Follow up with the patient's treating vns therapy physician revealed that she did not believe the patient's seizures were due to vns and added that the patient's generator had been replaced prophylactically. If present, an intermittent short-circuit could have potentially contributed to the patient's increased seizure activity, though this activity was still below pre-vns levels.

http://www.accessdata.fda.gov/scripts/cdrh/cfdocs/cfMAUDE/detail.cfm?mdrfoi__id=1476497


Title: Re: Short circuit
Post by: dennis100 on March 23, 2012, 08:51:45 AM
Model Number 302-30
Device Problem Low impedance
Event Date 06/07/2006
Event Type Malfunction
Event Description
As part of a retrospective complaint review associated with an investigation of low impedance events, the events in this complaint investigation were assessed for the possibility of a short-circuit condition in the implanted lead. Based on clinical symptoms and the diagnostic history of the pt's device, this file was found to be possibly related to a short-circuit condition. It was reported that a vns pt was experiencing an increase in seizures, below pre-vns baseline levels. The pt's treating vns therapy physician indicated that the pt's device had been programmed to a 1% duty cycle (30 seconds of stimulation /60 minutes of no stimulation). The physician adjusted the pt therapy settings in an effort to improve the pt's efficacy with therapy. Later, pt clinic notes were received indicating that the pt had fallen after having a seizure which resulted in a cut to his forehead and necessitated stitches. The clinic notes state that the pt's mother had mentioned that the pt had changed medications prior to this event. Device diagnostics performed two months after the pt's fall resulted in a dcdc code of 0.

Manufacturer Narrative
Device failure is suspected.

http://www.accessdata.fda.gov/scripts/cdrh/cfdocs/cfMAUDE/detail.cfm?mdrfoi__id=1476498


Title: Re: Short circuit
Post by: dennis100 on March 23, 2012, 08:52:06 AM
Model Number 300-20
Device Problem Low impedance
Event Date 01/01/2007
Event Type Malfunction
Event Description
As part of a retrospective complaint review associated with an investigation of low impedance events, the events in this complaint investigation were assessed for the possibility of a short-circuit condition in the implanted lead. Based on clinical symptoms and the diagnostic history of the patient's device, this file was not found to be possibly related to a short-circuit condition. Patient has a history of seizure flurries and it is not uncommon for the patient to have a flurry of seizures. The normal mode diagnostics indicate that the device is able to deliver it's programmed settings and was not at eos. Unknown cause from the site for the patient's seizure flurry, but is part of the patient's seizure history.

Manufacturer Narrative
Device malfunction is suspected, but did not contribute to a death or serious injury

http://www.accessdata.fda.gov/scripts/cdrh/cfdocs/cfMAUDE/detail.cfm?mdrfoi__id=1476499


Title: Re: Short circuit
Post by: dennis100 on March 23, 2012, 08:52:34 AM
Model Number 300-20
Device Problem Electrical shorting
Event Date 01/01/2007
Event Type Malfunction
Event Description
As part of a retrospective complaint review associated with an investigation of low impedance events, the events in this complaint investigation were assessed for the possibility of a short-circuit condition in the implanted lead. Based on clinical symptoms and the diagnostic history of the pt's device, this file was found to be possibly related to a short-circuit condition. It was initially reported that the pt began to "have a few breakthrough seizures which until now have been relatively well controlled for several years. " in addition, there was a concern of "early battery failure. " diagnostic testing found all systems intact and functioning normally with dcdc: 0 and eri = no. The pt's output current was increased to 2. 75ma which resulted in "an uncomfortable coughing and choking sensation in her ear and throat. " follow-up with the physician indicated that the pt's seizures were still below pre-vns levels which may have been related to the pt "getting sick due to infection. " the infection was not related to the vns but rather poor hygiene. The physician further explained that the pt's choking and coughing was related to intolerable settings as decreasing the pt's settings resolved the events. It was also noted that the pt was experiencing some weight loss. It was later reported on a follow-up that the pt is "continuing to tolerate the stimulator system well with no remarkable subjective complaints. There have been no changes in her general health status. " there is no allegation that the pt's weight loss is causing harm to the pt.

Manufacturer Narrative
Device malfunction is suspected, but did not contributed to a death or serious injury.

http://www.accessdata.fda.gov/scripts/cdrh/cfdocs/cfMAUDE/detail.cfm?mdrfoi__id=1476500


Title: Re: Short circuit
Post by: dennis100 on March 23, 2012, 08:52:58 AM
Model Number 300-20
Event Date 04/29/2008
Event Type Malfunction
Manufacturer Narrative
Device failure is suspected, but did not cause or contribute to a death or serious injury.

Event Description
As part of a retrospective complaint review associated with an investigation of low impedance events, the events in this complaint investigation were assessed for the possibility of a short-circuit condition in the implanted lead. Based on clinical symptoms and the diagnostic history of the pt's device, this file was found to be possibly related to a short-circuit condition. It was reported that the pt was experiencing an increase in seizures (below pre-vns-baseline). Per the physician, the believed cause of the increase is few missed doses of epilepsy medication. Device diagnostics were within normal limits with dc/dc code = 0. No further info is available at this time.

http://www.accessdata.fda.gov/scripts/cdrh/cfdocs/cfMAUDE/detail.cfm?mdrfoi__id=1476024


Title: Re: Short circuit
Post by: dennis100 on March 23, 2012, 08:53:25 AM
Model Number 302-20
Event Date 05/23/2008
Event Type Malfunction
Event Description
As part of a retrospective complaint review associated with an investigation of low impedance events, the events in this complaint investigation were assessed for the possibility of a short-circuit condition in the implanted lead. Based on clinical symptoms and the diagnostic history of the pt's device, this file was found to be possibly related to a short-circuit condition. It was reported that the pt was experiencing an increase in seizures (below pre-vns baseline) and had her generator prophylactically replaced. No further info is available to date.

Manufacturer Narrative
Device failure is suspected, but did not cause or contribute to a death or serious injury.

http://www.accessdata.fda.gov/scripts/cdrh/cfdocs/cfMAUDE/detail.cfm?mdrfoi__id=1476027


Title: Re: Short circuit
Post by: dennis100 on March 23, 2012, 08:53:54 AM
Model Number 302-20
Event Date 11/01/2007
Event Type Malfunction
Manufacturer Narrative
Device failure is suspected, but did not cause or contribute to death or serious injury.

Event Description
As part of a retrospective complaint review associated with an investigation of low impedance events, the events in this complaint investigation were assessed for the possibility of a short-circuit condition in the implanted lead. Based on clinical symptoms and the diagnostic history of the pt's device, this file was found to be possible related to a short-circuit condition. It was reported that the pt was coughing when the device stimulated. The physician turned the output current down which alleviated the coughing for a few months, but then it started again. The physician did not know why the pt could not tolerate the stimulation. The device was turned off for a few weeks, and then turned back on to 0. 5 ma. Attempts for further info have been unsuccessful to date.

http://www.accessdata.fda.gov/scripts/cdrh/cfdocs/cfMAUDE/detail.cfm?mdrfoi__id=1476029


Title: Re: Short circuit
Post by: dennis100 on March 23, 2012, 08:54:21 AM
Model Number 302-20
Event Date 09/12/2005
Event Type Malfunction
Manufacturer Narrative
Device failure is suspected, but did not cause or contribute to a death or serious injury.

Event Description
As part of a retrospective complaint review associated with an investigation of low impedance events, the events in this complaint investigation were assessed for the possibility of a short-circuit condition in the implanted lead. Based on clinical symptoms and the diagnostic history of the pt's device, this file was found to be possibly related to a short-circuit condition. Reporter indicated a vns pt was unable to feel regular or magnet mode vns stimulation

http://www.accessdata.fda.gov/scripts/cdrh/cfdocs/cfMAUDE/detail.cfm?mdrfoi__id=1476030


Title: Re: Short circuit
Post by: dennis100 on March 23, 2012, 08:54:46 AM
Model Number 302-20
Event Date 07/21/2005
Event Type Malfunction
Manufacturer Narrative
Conclusions - device failure is suspected, but did not cause or contributed to a death or serious injury.

Event Description
As part of a retrospective complaint review associated with an investigation a low impedance events, the events in this complaint investigation were assessed for the possibility of a short-circuit condition in the implanted lead. Based on clinical symptoms and the diagnostic history of the pt's device, this file was found to be possibly related to a short-circuit condition. Reporter indicated a vns pt could no longer feel vns stimulation

http://www.accessdata.fda.gov/scripts/cdrh/cfdocs/cfMAUDE/detail.cfm?mdrfoi__id=1476032


Title: Re: Short circuit
Post by: dennis100 on March 23, 2012, 08:55:41 AM
Model Number 300-UNK
Event Date 10/09/2004
Event Type Malfunction
Manufacturer Narrative
Device failure suspected.

Event Description
As part of a retrospective complaint review associated with an investigation of low impedance events, the events in this complaint investigation were assessed for the possibility of a short-circuit condition in the implanted lead. Based on clinical symptoms and the diagnostic history of the pt's device, this file was found to be possibly related to a short-circuit condition. It was reported in medwatch 1644487-2007-01852 that the vns pt had not had good seizure control over the last three years.

http://www.accessdata.fda.gov/scripts/cdrh/cfdocs/cfMAUDE/detail.cfm?mdrfoi__id=1476034


Title: Re: Short circuit
Post by: dennis100 on March 23, 2012, 08:56:10 AM
Model Number 300-20
Event Date 01/01/2006
Event Type Malfunction
Manufacturer Narrative
Device failure is suspected, but did not cause or contribute to a death or serious injury.

Event Description
It was reported that the patient showed increase in seizures but not above pre-vns baseline. The site thought that the battery was nearing end-of-service, however, battery life calculation showed approximately 2. 53 years before eri=yes. Site mentioned about dcdc code equal to zero and they thought there might have been some lead issue. Good faith attempts to obtain additional information was unsuccessful. As part of a retrospective complaint review associated with an investigation of low impedance events, the events in this complaint investigation were assessed for the possibility of a short-circuit condition in the implanted lead. Based on clinical symptoms and the diagnostic history of the patient's device, this file was found to be possibly related to a short-circuit condition.

http://www.accessdata.fda.gov/scripts/cdrh/cfdocs/cfMAUDE/detail.cfm?mdrfoi__id=1478393


Title: Re: Short circuit
Post by: dennis100 on March 23, 2012, 08:56:39 AM
Model Number 302-20
Event Date 01/01/2005
Event Type Malfunction
Manufacturer Narrative
Device failure is suspected, but did not cause or contribute to a death or serious injury.

Event Description
It was reported that the patient had increase in cough. Patient had (b) (6), but vns system normally elicits the cough. Cough is worsened at night. As part of a retrospective complaint review associated with an investigation of low impedance events, the events in this complaint investigation were assessed for the possibility of a short-circuit condition in the implanted lead. Based on clinical symptoms and the diagnostic history of the patient's device, this file was found to be possibly related to a short-circuit condition.

http://www.accessdata.fda.gov/scripts/cdrh/cfdocs/cfMAUDE/detail.cfm?mdrfoi__id=1478394


Title: Re: Short circuit
Post by: dennis100 on March 23, 2012, 08:57:08 AM
Model Number 302-20
Event Date 05/01/2005
Event Type Malfunction
Event Description
Please refer to report # 1644487-2005-00365. As part of a retrospective complaint review associated with an investigation of low impedance events, the events in this complaint investigation were assessed for the possibility of a short-circuit condition in the implanted lead. Based on clinical symptoms and the diagnostic history of the patient's device, this file was found to be possibly related to a short-circuit condition.

Manufacturer Narrative
Device failure is suspected, but did not cause or contribute to a death or serious injury.

http://www.accessdata.fda.gov/scripts/cdrh/cfdocs/cfMAUDE/detail.cfm?mdrfoi__id=1478396


Title: Re: Short circuit
Post by: dennis100 on March 23, 2012, 08:57:39 AM
Model Number 302-20
Event Date 01/01/2005
Event Type Malfunction
Manufacturer Narrative
Device failure is suspected, but did not cause or contribute to a death or serious injury.

Event Description
As part of a retrospective complaint review associated with an investigation of low impedance events, the events in this complaint investigation were assessed for the possibility of a short-circuit condition in the implanted lead. Based on clinical symptoms and the diagnostic history of the patient's device, this file was found to be possibly related to a short-circuit condition. It was reported that the patient had an increase in seizures and patient's mom believe that the battery was dead or not working properly. No additional information was received.

http://www.accessdata.fda.gov/scripts/cdrh/cfdocs/cfMAUDE/detail.cfm?mdrfoi__id=1478398


Title: Re: Short circuit
Post by: dennis100 on March 23, 2012, 08:58:13 AM
Model Number 302-20
Event Date 03/01/2009
Event Type Malfunction
Manufacturer Narrative
Device failure is suspected, but did not cause or contribute to a death or serious injury.

Event Description
As part of a retrospective complaint review associated with an investigation of low impedance events, the events in this complaint investigation were assessed for the possibility of a short-circuit condition in the implanted lead. Based on clinical symptoms and the diagnostic history of the patient's device, this file was found to be possibly related to a short-circuit condition. It was reported that the patient is having pain in her neck, ear, throat, and mouth with stimulation. No trauma or manipulation was reported. Patient's device was turned off and then turned back on once pain disappeared. Patient was set to low output current and is doing great now.

http://www.accessdata.fda.gov/scripts/cdrh/cfdocs/cfMAUDE/detail.cfm?mdrfoi__id=1478400


Title: Re: Short circuit
Post by: dennis100 on March 23, 2012, 08:58:46 AM
Model Number 300-20
Event Date 10/01/2007
Event Type Malfunction
Event Description
As part of a retrospective complaint review associated with an investigation of low impedance events, the events in this complaint investigation were assessed for the possibility of a short-circuit condition in the implanted lead. Based on clinical symptoms and the diagnostic history of the patient's device, this file was found to be possibly related to a short-circuit condition. It was reported in medwatch 1644487-2007-01890 that the patient was experiencing an increase in seizures, which was later found to be less than her baseline level of seizures, and was believed to be due to the generator nearing eos.

Manufacturer Narrative
Device failure suspected.

http://www.accessdata.fda.gov/scripts/cdrh/cfdocs/cfMAUDE/detail.cfm?mdrfoi__id=1478410


Title: Re: Short circuit
Post by: dennis100 on March 23, 2012, 08:59:25 AM
Model Number 300-20
Event Date 09/01/2007
Event Type Malfunction
Event Description
As part of a retrospective complaint review associated with an investigation of low impedance events, the events in this complaint investigation were assessed for the possibility of a short-circuit condition in the implanted lead. Based on clinical symptoms and the diagnostic history of the patient's device, this file was found to be possibly related to a short-circuit condition. Reporter indicated that the patient was experiencing an increase in seizure activity, however, it was not worse than before starting vns therapy, and the physician felt the event may be due to stressors in the patient's life, and not vns therapy.

Manufacturer Narrative
Device failure suspected.

http://www.accessdata.fda.gov/scripts/cdrh/cfdocs/cfMAUDE/detail.cfm?mdrfoi__id=1478411


Title: Re: Short circuit
Post by: dennis100 on March 23, 2012, 08:59:59 AM
Model Number 300-20
Event Date 09/04/2007
Event Type Malfunction
Event Description
As part of a retrospective complaint review associated with an investigation of low impedance events, the events in this complaint investigation were assessed for the possibility of a short-circuit condition in the implanted lead. Based on clinical symptoms and the diagnostic history of the patient's device, this file was found to be possibly related to a short-circuit condition. Reporter indicated that the patient was experiencing pain and muscle spasms in his neck during stimulation, that were more tolerable at lower output current settings.

Manufacturer Narrative
Device failure suspected.

http://www.accessdata.fda.gov/scripts/cdrh/cfdocs/cfMAUDE/detail.cfm?mdrfoi__id=1478412


Title: Re: Short circuit
Post by: dennis100 on March 23, 2012, 09:00:36 AM
Model Number 302-20
Event Date 12/14/2007
Event Type Malfunction
Event Description
As part of a retrospective complaint review associated with an investigation of low impedance events, the events in this complaint investigation were assessed for the possibility of a short-circuit condition in the implanted lead. Based on clinical symptoms and the diagnostic history of the patient's device, this file was found to be possibly related to a short-circuit condition. It was reported that the patient was experiencing an increase in seizures back to pre-vns baseline. The physician did not believe the increase was related to vns therapy and prior to the onset, that patient had changed her depakote dosing. The physician increased the patient's medication to address the event. No further information is available.

Manufacturer Narrative
Device failure is suspected, but did not cause or contribute to a death or serious injury.

http://www.accessdata.fda.gov/scripts/cdrh/cfdocs/cfMAUDE/detail.cfm?mdrfoi__id=1478413


Title: Re: Short circuit
Post by: dennis100 on March 23, 2012, 09:01:12 AM
Model Number 302-30
Event Date 03/01/2007
Event Type Malfunction
Event Description
Initial reporter indicated that their patient was having an increase in seizures. In the last 2. 5 months he has been having a lot of seizures. Not over his pre vns baseline and the doctor is attributing them to the patient's stress that he is having at the moment. As part of a retrospective complaint review associated with an investigation of how impedance events, the events in this complaint investigation were assessed for the possibility of a short-circuit condition in the implanted lead. Based on clinical symptoms and the diagnostic history of the patient's device, this file was found to be possibly replated to a short-circuit condition.

Manufacturer Narrative
Device malfunction suspected, but did not cause or contribute to a death or serious injury.

http://www.accessdata.fda.gov/scripts/cdrh/cfdocs/cfMAUDE/detail.cfm?mdrfoi__id=1478431


Title: Re: Short circuit
Post by: dennis100 on March 23, 2012, 09:01:49 AM
Model Number 300-20
Event Date 03/15/2007
Event Type Malfunction
Event Description
It was reported that a vns patient experienced cough and subsequent muscle spasms in the neck with vns stimulation. X-rays were taken and reviewed at manufacturer no anomalies were observed. The patient's treating physician did witness the muscle spasms and correlated it with stimulation cycles. The patient's device was disabled and both cough and muscle spasms resolved. There are no plans to turn on the device. As part of a retrospective complaint review associated with an investigation of low impedance events, the events in this complaint investigation were assessed for the possibility of a short-circuit condition in the implanted lead. Based on clinical symptoms and the diagnostic history of the patient's device, this file was found to be possibly related to a short-circuit condition.

Manufacturer Narrative
Manufacturer review of x-rays. Results - x-rays reviewed by manufacturer, no gross lead discontinuities visualized. Conclusions - device malfunction suspected, but did not cause or contribute to a death or serious injury.

http://www.accessdata.fda.gov/scripts/cdrh/cfdocs/cfMAUDE/detail.cfm?mdrfoi__id=1478433


Title: Re: Short circuit
Post by: dennis100 on March 23, 2012, 09:02:22 AM
Model Number 302-20
Event Date 08/17/2006
Event Type Malfunction
Manufacturer Narrative
Device malfunction suspected, but did not cause or contribute to a death.

Event Description
Initial reporter indicated that their patient was seen in their clinic and had on a systems test dcdc 7 limit high eri no and normal mode test dcdc 7 limit high eri no. It was additionally reported the patient had drop attack seizures and had been having more drop attacks recently. Last date diagnostics were taken was (b) (6) 2005. Normal mode ok/ok/dcdc 0, systems test ok/ok/dcdc 3. The patient's x-rays were not sent to the manufacturer but the site reported that they reviewed x-rays and there was an obvious break and lead coiled up. The treating physician believed the cause of the patient's lead break was related to a very bad fall related to drop attacks. The patient had their lead replaced but it was not returned to the manufacturer for analysis. As part of a retrospective complaint review associated with an investigation of low impedance events, the events in this complaint investigation were assessed for the possibility of a short-circuit condition in the implanted lead. Based on clinical symptoms and the diagnostic history of the patient's device, this file was found to be possibly related to a short-circuit condition.

http://www.accessdata.fda.gov/scripts/cdrh/cfdocs/cfMAUDE/detail.cfm?mdrfoi__id=1478437


Title: Re: Short circuit
Post by: dennis100 on March 23, 2012, 09:02:57 AM
Model Number 302-20
Event Date 07/01/2006
Event Type Malfunction
Manufacturer Narrative
Device malfunction suspected, but did not cause or contribute to a death or serious injury.

Event Description
It was reported that a vns patient was working in an e. R. And got close to an mri machine while in use. The patient subsequently experienced a sensation of strong stimulation and had a gagging episode for about 20 minutes. The treating physician indicated that both events were believed to be related to vns and that the mri most likely caused the vns to "trigger". As part of a retrospective complaint review associated with an investigation of low impedance events, the events in this complaint investigation were assessed for the possibility of a short-circuit condition in the implanted lead. Based on clinical symptoms and the diagnostic history of the patient's device, this file was found to be possibly related to a short-circuit condition.

http://www.accessdata.fda.gov/scripts/cdrh/cfdocs/cfMAUDE/detail.cfm?mdrfoi__id=1478442


Title: Re: Short circuit
Post by: dennis100 on March 23, 2012, 09:03:30 AM
Model Number 300-20
Event Date 06/01/2006
Event Type Malfunction
Manufacturer Narrative
Device malfunction suspected, but did not cause or contribute to a death.

Event Description
It was reported that the patient was experiencing shocking sensation with stimulation that the patient had been having for over a year. Additionally it was reported that the patient was having prolonged seizures lasting up to two hours long. Previously their seizures were one hour long. The patient, it was reported, had a large amount of scar tissue around their nerve. The patient had not had any falls or injuries preceding their shocking sensation. Full revision surgery was performed. The explanted products will not be returned for analysis. As part of a retrospective complaint review associated with an investigation of low impedance events, the events in this complaint investigation were assessed for the possibility of a short-circuit condition in the implanted lead. Based on clinical symptoms and the diagnostic history of the patient's device, this file was found to be possibly related to a short-circuit condition.

http://www.accessdata.fda.gov/scripts/cdrh/cfdocs/cfMAUDE/detail.cfm?mdrfoi__id=1478444


Title: Re: Short circuit
Post by: dennis100 on March 23, 2012, 09:04:03 AM
Model Number 302-20
Event Date 06/01/2006
Event Type Malfunction
Manufacturer Narrative
Device malfunction suspected, but did not cause or contribute to a death or serious injury.

Event Description
The patient reported to manufacturer that they were experiencing throat pain, a stiffening of his neck, and breathing problems with stimulation following an increase in device output current. The events reportedly resolved following a subsequent decrease in device settings. It was later reported that the patient was again having trouble breathing and experienced painful stimulation and vomiting with magnet usage. Those events reportedly resolved following another programming change. As part of a retrospective complaint review associated with an investigation of low impedance events, the events in this complaint investigation were assessed for the possibility of a short-circuit condition in the implanted lead. Based on clinical symptoms and the diagnostic history of the patient's device, this file was found to be possibly related to a short-circuit condition.

http://www.accessdata.fda.gov/scripts/cdrh/cfdocs/cfMAUDE/detail.cfm?mdrfoi__id=1478447


Title: Re: Short circuit
Post by: dennis100 on March 23, 2012, 09:04:30 AM
Model Number 302-20
Device Problems Vibration; Low impedance
Event Date 09/01/2007
Event Type Malfunction
Manufacturer Narrative
Device failure suspected.

Event Description
As part of a retrospective complaint review associated with an investigation of low impedance events, the events in this complaint investigation were assessed for the possibility of a short-circuit condition in the implanted lead. Based on clinical symptoms and the diagnostic history of the pt's device, this file was found to be possibly related to a short-circuit condition. Reporter indicated that the pt was experiencing painful stimulation and a "vibration" of the generator in the chest area. As there are no mechanical component which could cause a vibration, it was likely muscle spasms. The event resolved when the device was disabled using the magnet, and the physician has opted to turn the device output to 0ma.

http://www.accessdata.fda.gov/scripts/cdrh/cfdocs/cfMAUDE/detail.cfm?mdrfoi__id=1409617


Title: Re: Short circuit
Post by: dennis100 on March 23, 2012, 09:05:05 AM
Model Number 302-20
Device Problems Vibration; Low impedance
Event Date 09/01/2007
Event Type Malfunction
Manufacturer Narrative
Device failure suspected.

Event Description
As part of a retrospective complaint review associated with an investigation of low impedance events, the events in this complaint investigation were assessed for the possibility of a short-circuit condition in the implanted lead. Based on clinical symptoms and the diagnostic history of the pt's device, this file was found to be possibly related to a short-circuit condition. Reporter indicated that the pt was experiencing painful stimulation and a "vibration" of the generator in the chest area. As there are no mechanical component which could cause a vibration, it was likely muscle spasms. The event resolved when the device was disabled using the magnet, and the physician has opted to turn the device output to 0ma.

http://www.accessdata.fda.gov/scripts/cdrh/cfdocs/cfMAUDE/detail.cfm?mdrfoi__id=1475708


Title: Re: Short circuit
Post by: dennis100 on March 23, 2012, 09:05:30 AM
Model Number 302-20
Device Problems Low impedance; Electrical shorting
Event Date 07/20/2007
Event Type Malfunction
Manufacturer Narrative
Device failure is suspected.

Event Description
As part of a retrospective complaint review associated with an investigation of low impedance events, the events in this complaint investigation were assessed for the possibility of a short-circuit condition in the implanted lead. Based on clinical symptoms and the diagnostic history of the pt's device, this file was found to be possibly related to a short-circuit condition. It was reported that the pt was experiencing a mild cough during stimulation. The physician stated that the event was definitely related to stimulation, but was mild.

http://www.accessdata.fda.gov/scripts/cdrh/cfdocs/cfMAUDE/detail.cfm?mdrfoi__id=1475709


Title: Re: Short circuit
Post by: dennis100 on March 23, 2012, 09:05:55 AM
Model Number 300-20
Event Date 10/29/2001
Event Type Malfunction
Event Description
As part of a retrospective complaint review associated with an investigation of low impedance events, the events in this complaint investigation were assessed for the possibility of a short-circuit condition in the implanted lead. Based on clinical symptoms and the diagnostic history of the pt's device, this file was found to be possibly related to a short-circuit condition. The physician reported that the pt was experiencing an increase in seizure activity. The pt's generator was replaced, however, no additional interventions or x-rays were taken to address this event.

Manufacturer Narrative
Device failure is suspected, but did not cause or contributed to a death or serious injury.

http://www.accessdata.fda.gov/scripts/cdrh/cfdocs/cfMAUDE/detail.cfm?mdrfoi__id=1475716


Title: Re: Short circuit
Post by: dennis100 on March 23, 2012, 09:06:19 AM
Model Number 302-20
Event Date 10/01/2007
Event Type Malfunction
Event Description
As part of a retrospective complaint review associated with an investigation of low impedance events, the events in this complaint investigation were assessed for the possibility of a short-circuit condition in the implanted lead. Based on clinical symptoms and the diagnostic history of the pt's device, this file was found to be possibly related to a short-circuit condition. The pt's physician had reported that the pt's behavior and seizure activity had worsened to baseline levels. Medications and vns settings were changed in response to the events.

Manufacturer Narrative
Device failure is suspected, but did not cause or contribute to a death or serious injury.

http://www.accessdata.fda.gov/scripts/cdrh/cfdocs/cfMAUDE/detail.cfm?mdrfoi__id=1475717


Title: Re: Short circuit
Post by: dennis100 on March 23, 2012, 09:06:43 AM
Model Number 302-20
Event Date 09/01/2007
Event Type Malfunction
Event Description
As part of a retrospective complaint review associated with an investigation of low impedance events, the events in this complaint investigation were assessed for the possibility of a short-circuit condition in the implanted lead. Based on clinical symptoms and the diagnostic history of the pt's device, this file was found to be possibly related to a short-circuit condition. The pt had initially reported pain at the electrode site that would occur with device stimulation. No x-rays were taken, and no interventions were taken to address this event.

Manufacturer Narrative
Device failure is suspected, but did not cause or contribute to a death or serious injury.

http://www.accessdata.fda.gov/scripts/cdrh/cfdocs/cfMAUDE/detail.cfm?mdrfoi__id=1475718


Title: Re: Short circuit
Post by: dennis100 on March 23, 2012, 09:07:11 AM
Model Number 300-20
Event Date 09/01/2007
Event Type Malfunction
Manufacturer Narrative
Device failure is suspected, but did not cause or contribute to a death or serious injury.

Event Description
As part of a retrospective complaint review associated with an investigation of low impedance events, the events in this complaint investigation were assessed for the possibility of a short-circuit condition in the implanted lead. Based on clinical symptoms and the diagnostic history of the pt's device, this file was found to be possibly related to a short-circuit condition. The pt had reported experiencing painful stimulation and an electrical sensation during device stimulation. No x-rays or interventions were taken to address this event.

http://www.accessdata.fda.gov/scripts/cdrh/cfdocs/cfMAUDE/detail.cfm?mdrfoi__id=1475719


Title: Re: Short circuit
Post by: dennis100 on March 23, 2012, 09:07:37 AM
Model Number 302-20
Event Date 02/04/2008
Event Type Malfunction
Manufacturer Narrative
Device failure is suspected, but did not cause or contribute to a death or serious injury.

Event Description
As part of a retrospective complaint review associated with an investigation of low impedance events, the events in this complaint investigation were assessed for the possibility of a short-circuit condition in the implanted lead. Based on clinical symptoms and the diagnostic history of the pt's device, this file was found to be possibly related to a short-circuit condition. The physician reported that the pt had an increase in seizure activity. No interventions were taken to address this event.

http://www.accessdata.fda.gov/scripts/cdrh/cfdocs/cfMAUDE/detail.cfm?mdrfoi__id=1475720


Title: Re: Short circuit
Post by: dennis100 on March 23, 2012, 09:08:03 AM
Model Number 302-30
Event Date 12/26/2007
Event Type Malfunction
Event Description
As part of a retrospective complaint review associated with an investigation of low impedance events, the events in this complaint investigation were assessed for the possibility of a short-circuit condition in the implanted lead. Based on clinical symptoms and the diagnostic history of the pt's device, this file was found to be possibly related to a short-circuit condition. It was reported that the pt underwent a lead revision surgery due to the pt twisting the lead and causing it to break. The damage to the lead was visible during revision surgery. The explanted lead was discarded and will not be returned for product analysis.

Manufacturer Narrative
Device failure is suspected, but did not cause or contribute to a death or serious injury

http://www.accessdata.fda.gov/scripts/cdrh/cfdocs/cfMAUDE/detail.cfm?mdrfoi__id=1475721


Title: Re: Short circuit
Post by: dennis100 on March 23, 2012, 09:08:28 AM
Model Number 302-20
Device Problems Vibration; Low impedance
Event Date 09/01/2007
Event Type Malfunction
Manufacturer Narrative
Device failure suspected.

Event Description
As part of a retrospective complaint review associated with an investigation of low impedance events, the events in this complaint investigation were assessed for the possibility of a short-circuit condition in the implanted lead. Based on clinical symptoms and the diagnostic history of the pt's device, this file was found to be possibly related to a short-circuit condition. Reporter indicated that the pt was experiencing painful stimulation and a "vibration" of the generator in the chest area. As there are no mechanical component which could cause a vibration, it was likely muscle spasms. The event resolved when the device was disabled using the magnet, and the physician has opted to turn the device output to 0ma.

http://www.accessdata.fda.gov/scripts/cdrh/cfdocs/cfMAUDE/detail.cfm?mdrfoi__id=1475708


Title: Re: Short circuit
Post by: dennis100 on March 23, 2012, 11:09:29 AM
Model Number 302-20
Device Problems Low impedance; Electrical shorting
Event Date 07/20/2007
Event Type Malfunction
Manufacturer Narrative
Device failure is suspected.

Event Description
As part of a retrospective complaint review associated with an investigation of low impedance events, the events in this complaint investigation were assessed for the possibility of a short-circuit condition in the implanted lead. Based on clinical symptoms and the diagnostic history of the pt's device, this file was found to be possibly related to a short-circuit condition. It was reported that the pt was experiencing a mild cough during stimulation. The physician stated that the event was definitely related to stimulation, but was mild.

http://www.accessdata.fda.gov/scripts/cdrh/cfdocs/cfMAUDE/detail.cfm?mdrfoi__id=1475709


Title: Re: Short circuit
Post by: dennis100 on March 23, 2012, 11:09:58 AM
Model Number 300-20
Event Date 10/29/2001
Event Type Malfunction
Event Description
As part of a retrospective complaint review associated with an investigation of low impedance events, the events in this complaint investigation were assessed for the possibility of a short-circuit condition in the implanted lead. Based on clinical symptoms and the diagnostic history of the pt's device, this file was found to be possibly related to a short-circuit condition. The physician reported that the pt was experiencing an increase in seizure activity. The pt's generator was replaced, however, no additional interventions or x-rays were taken to address this event.

Manufacturer Narrative
Device failure is suspected, but did not cause or contributed to a death or serious injury.

http://www.accessdata.fda.gov/scripts/cdrh/cfdocs/cfMAUDE/detail.cfm?mdrfoi__id=1475716


Title: Re: Short circuit
Post by: dennis100 on March 23, 2012, 11:10:22 AM
Model Number 302-20
Event Date 10/01/2007
Event Type Malfunction
Event Description
As part of a retrospective complaint review associated with an investigation of low impedance events, the events in this complaint investigation were assessed for the possibility of a short-circuit condition in the implanted lead. Based on clinical symptoms and the diagnostic history of the pt's device, this file was found to be possibly related to a short-circuit condition. The pt's physician had reported that the pt's behavior and seizure activity had worsened to baseline levels. Medications and vns settings were changed in response to the events.

Manufacturer Narrative
Device failure is suspected, but did not cause or contribute to a death or serious injury.

http://www.accessdata.fda.gov/scripts/cdrh/cfdocs/cfMAUDE/detail.cfm?mdrfoi__id=1475717


Title: Re: Short circuit
Post by: dennis100 on March 23, 2012, 11:10:51 AM
Model Number 302-20
Event Date 09/01/2007
Event Type Malfunction
Event Description
As part of a retrospective complaint review associated with an investigation of low impedance events, the events in this complaint investigation were assessed for the possibility of a short-circuit condition in the implanted lead. Based on clinical symptoms and the diagnostic history of the pt's device, this file was found to be possibly related to a short-circuit condition. The pt had initially reported pain at the electrode site that would occur with device stimulation. No x-rays were taken, and no interventions were taken to address this event.

Manufacturer Narrative
Device failure is suspected, but did not cause or contribute to a death or serious injury

http://www.accessdata.fda.gov/scripts/cdrh/cfdocs/cfMAUDE/detail.cfm?mdrfoi__id=1475718


Title: Re: Short circuit
Post by: dennis100 on March 23, 2012, 11:11:18 AM
Model Number 300-20
Event Date 09/01/2007
Event Type Malfunction
Manufacturer Narrative
Device failure is suspected, but did not cause or contribute to a death or serious injury.

Event Description
As part of a retrospective complaint review associated with an investigation of low impedance events, the events in this complaint investigation were assessed for the possibility of a short-circuit condition in the implanted lead. Based on clinical symptoms and the diagnostic history of the pt's device, this file was found to be possibly related to a short-circuit condition. The pt had reported experiencing painful stimulation and an electrical sensation during device stimulation. No x-rays or interventions were taken to address this event

http://www.accessdata.fda.gov/scripts/cdrh/cfdocs/cfMAUDE/detail.cfm?mdrfoi__id=1475719


Title: Re: Short circuit
Post by: dennis100 on March 23, 2012, 11:11:45 AM
Model Number 302-20
Event Date 02/04/2008
Event Type Malfunction
Manufacturer Narrative
Device failure is suspected, but did not cause or contribute to a death or serious injury.

Event Description
As part of a retrospective complaint review associated with an investigation of low impedance events, the events in this complaint investigation were assessed for the possibility of a short-circuit condition in the implanted lead. Based on clinical symptoms and the diagnostic history of the pt's device, this file was found to be possibly related to a short-circuit condition. The physician reported that the pt had an increase in seizure activity. No interventions were taken to address this event.

http://www.accessdata.fda.gov/scripts/cdrh/cfdocs/cfMAUDE/detail.cfm?mdrfoi__id=1475720


Title: Re: Short circuit
Post by: dennis100 on March 23, 2012, 11:12:11 AM
Model Number 302-30
Event Date 12/26/2007
Event Type Malfunction
Event Description
As part of a retrospective complaint review associated with an investigation of low impedance events, the events in this complaint investigation were assessed for the possibility of a short-circuit condition in the implanted lead. Based on clinical symptoms and the diagnostic history of the pt's device, this file was found to be possibly related to a short-circuit condition. It was reported that the pt underwent a lead revision surgery due to the pt twisting the lead and causing it to break. The damage to the lead was visible during revision surgery. The explanted lead was discarded and will not be returned for product analysis.

Manufacturer Narrative
Device failure is suspected, but did not cause or contribute to a death or serious injury

http://www.accessdata.fda.gov/scripts/cdrh/cfdocs/cfMAUDE/detail.cfm?mdrfoi__id=1475721


Title: Re: Short circuit
Post by: dennis100 on March 23, 2012, 11:12:45 AM
Model Number 300-30
Event Date 04/08/2008
Event Type Malfunction
Event Description
Reporter indicated that their vns pt was not feeling stimulation. Review of programming history showed the pt's systems test to have a dcdc code of 0 meaning that there is a possibility of a short-circuit condition in the implanted lead. Based on clinical symptoms and the diagnostic history of the pt's device, this file was found to be possibly related to a short-circuit condition. Good faith attempts are being made of additional details about the event.

Manufacturer Narrative
Device malfunction suspected but did not cause or contribute to a death or serious injury.

http://www.accessdata.fda.gov/scripts/cdrh/cfdocs/cfMAUDE/detail.cfm?mdrfoi__id=1497095


Title: Re: Short circuit
Post by: dennis100 on March 23, 2012, 11:13:11 AM
Model Number 302-20
Event Date 07/23/2007
Event Type Malfunction
Manufacturer Narrative
Device malfunction is suspected, but did not cause a death or serious injury.

Event Description
As part of a retrospective complaint review associated with an investigation of low impedance events, the events in this complaint investigation were assessed for the possibility of a short-circuit condition in the implanted lead. Based on clinical symptoms and the diagnostic history of the pt's device, this file was found to be possibly related to a short-circuit condition. It was reported, a pt was experiencing magnet failure as the magnet would not stop the device from stimulating. Also the pt was experiencing continuous stimulation that lasted for 3-4 hours after a magnet stimulation. Due to the continuous stimulation, the pt was experiencing muscle spasms. The pt reported increased seizures. The nurse practitioner in the physician's office stated, the reported issues were not related to vns therapy. She stated, the pt was experiencing high anxiety and cardiac issues that caused the "perceived issues". The np re-educated the pt on swiping the magnet and what the intended results would be and has scheduled the pt for a cardiac cath.

http://www.accessdata.fda.gov/scripts/cdrh/cfdocs/cfMAUDE/detail.cfm?mdrfoi__id=1476458


Title: Re: Short circuit
Post by: dennis100 on March 24, 2012, 04:42:58 AM
Model Number 302-20
Event Date 08/01/2008
Event Type Malfunction
Manufacturer Narrative
Device failure is suspected, but did not cause or contribute to a death.

Event Description
It was reported by the pt's treating physician that pt has been experiencing increase in seizures (not above pre-vns) and longer seizures duration over the past one year. Pt also use to typically cough and had voice alteration with stimulation but she does not have those symptoms anymore. Further info from the physician indicated that diagnostics were done and it results in dcdc code of 0 on system test. It was informed to the physician a possibility of short circuit condition. Physician does not plan to take any intervention at this point other than monitoring the pt for a while and try to change settings. Physician believes that pt's symptoms are related to vns therapy and possibly related to the short circuit condition. Based on clinical symptoms and the diagnostic results of the pt's device, this file was found to be possibly related to a short-circuit condition.

http://www.accessdata.fda.gov/scripts/cdrh/cfdocs/cfMAUDE/detail.cfm?mdrfoi__id=1506025


Title: Re: Short circuit
Post by: dennis100 on March 24, 2012, 04:43:24 AM
Model Number 300-20
Device Problem Circuit Failure
Event Type Malfunction
Event Description
It was initially reported that the patient's seizure control has not been as good over the last few years. It was also noted that the patient has been diagnosed with lennox gastaut epilepsy. During a review of the patient's diagnostic/programming history, it was observed that there is a possible short circuit condition that occurred about 2004-2006. The site has not made a determination about the possibilities of surgery revision or exploration. Good faith attempts to obtain additional information have been unsuccessful to date.

http://www.accessdata.fda.gov/scripts/cdrh/cfdocs/cfMAUDE/detail.cfm?mdrfoi__id=1516851


Title: Re: Short circuit
Post by: dennis100 on March 24, 2012, 04:43:54 AM
Model Number 302-20
Event Date 07/01/2009
Event Type Malfunction
Event Description
It was reported that the pt had dc/dc code = 0 on system diagnostics. Pt also experienced a "spike" in seizures in (b) (6) and (b) (6) of 2009, but this was below pre-vns baseline levels. Because of pt's developmental delay, they are unable to tell if she is feeling stimulation, but she does not show any signs of discomfort. The pt's medications had been changed in (b) (6) 2009, but no changes to vns have been made. No interventions have been taken or planned at this point. A short circuit condition is suspected in the lead, but this cannot be confirmed at this time.

http://www.accessdata.fda.gov/scripts/cdrh/cfdocs/cfMAUDE/detail.cfm?mdrfoi__id=1521141


Title: Re: Short circuit
Post by: dennis100 on March 24, 2012, 04:44:27 AM
Event Date 01/01/2009
Event Type Malfunction
Event Description
It was reported that this pt had a possible short circuit condition. No further information is available. Attempts for further information have been unsuccessful to date.

http://www.accessdata.fda.gov/scripts/cdrh/cfdocs/cfMAUDE/detail.cfm?mdrfoi__id=1510631


Title: Re: Short circuit
Post by: dennis100 on March 24, 2012, 09:15:56 AM
Model Number 302-20
Event Date 07/01/2009
Event Type Malfunction
Manufacturer Narrative
Device failure suspected.

Event Description
Reporter indicated that during a generator replacement surgery, it was noted that portions of the patient's neck appeared to be stimulated. Examination of the lead by the surgeon found that there was a bubble, and abrasion in the lead insulation. The surgeon suspected that the issue the patient was experiencing was likely due to current being leaked to the tissues surrounding the vagus nerve, instead of only the vagus nerve. The surgeon proceeded to replace both the generator and the lead. Attempts to have the explanted lead returned for analysis were unsuccessful as the product was discarded.

http://www.accessdata.fda.gov/scripts/cdrh/cfdocs/cfMAUDE/detail.cfm?mdrfoi__id=1551281


Title: Re: Short circuit
Post by: dennis100 on March 24, 2012, 09:16:33 AM
Model Number 103
Device Problem Connection issue
Event Date 09/01/2009
Event Type Malfunction
Event Description
During investigation in reference medwatch number: 1644487-2009-01743 for high impedance short circuit report x-rays were received for review. Manufacturer review of films noted the lead connector pin did not appear to be fully inserted into the generator connector block based on the view available. Based on the x-rays reviewed the appearance of the lead pin not being fully inserted could possibly be the cause of the high lead impedance, but a lead fracture cannot be ruled out. Surgical exploration has been planned for the patient on (b) (6) 2009. The patient in (b) (6) 2009 had high lead impedance that resolved in the or during their vns generator replacement and postoperatively was discovered to have high lead impedance again. The vns was programmed off.

Manufacturer Narrative
Manufacturer review of x-rays of implanted device. X-rays reviewed by the manufacturer, no gross lead discontinuities noted. Appeared based on one view only, pin to not be fully inserted into the header of the generator.

http://www.accessdata.fda.gov/scripts/cdrh/cfdocs/cfMAUDE/detail.cfm?mdrfoi__id=1551036


Title: Re: Short circuit
Post by: dennis100 on March 24, 2012, 09:17:10 AM
Model Number 300-20
Event Date 01/01/2009
Event Type Malfunction
Manufacturer Narrative
Device failure is suspected, but did not cause or contribute to a death or serious injury.

Event Description
It was reported that the vns pt was seen for a follow up visit and the pt reported that she was no longer feeling stimulation of the device, and when a system diagnostic test was performed, the pt did not have the same clinical response that she had in the past during the diagnostic test. The site reported that the pt still does have seizure clusters, however, the seizure frequency remains much improved in relation to pre-vns seizure frequency. Based on clinical symptoms and the diagnostic history of the pt's device, this event was found to be possibly related to a short-circuit condition. Good faith attempts to obtain additional info have been made, but have been unsuccessful to date. Revision surgery is likely.

Manufacturer Narrative
Device failure is suspected, but did not cause or contribute to a death or serious injury.

http://www.accessdata.fda.gov/scripts/cdrh/cfdocs/cfMAUDE/detail.cfm?mdrfoi__id=1553670


Title: Re: Short circuit
Post by: dennis100 on March 24, 2012, 10:34:03 AM
Model Number 302-20
Event Date 11/01/2009
Event Type Malfunction
Event Description
Reporter indicated that the pt was not feeling stimulation. Even after turning the settings up relatively high for this pt, stimulation was still not perceived. The physician found a dcdc code of 0 on a system diagnostic test, which can be indicative of a short circuit in the lead, especially in conjunction with the reported lack of perception of stimulation. X-rays were taken, and a copy sent to the manufacturer for analysis. There was an area of suspicion in the lead directly after it leaves the header of the generator, the lead appears to make an extreme angle, and is possibly fractured and short circuiting, but due to limited images, this event could not be confirmed. Requests to additional x-rays to better visualize the area in question will not be fulfilled as the physician feels this will take too long. The pt has been sent to a surgeon for a surgical consult for device revision or replacement, but no surgical plans are known at this time

http://www.accessdata.fda.gov/scripts/cdrh/cfdocs/cfMAUDE/detail.cfm?mdrfoi__id=1581041


Title: Re: Short circuit
Post by: dennis100 on March 26, 2012, 11:32:25 AM
Model Number 300-20
Event Date 12/14/2009
Event Type Malfunction
Manufacturer Narrative
Device failure is suspected, but did not cause or contribute to a death or serious injury.

Event Description
It was reported to the mfr that the vns pt has been experiencing painful stimulation in the neck area erratically due to unk reason. Info from the treating neurologist revealed the pt had been doing well since implant in (b) (6) 2002. Furthermore, there were no reports of pt trauma or manipulation that could have contributed to the reported event. Moreover, both system and normal mode diagnostics were performed at the time of the event and resulted within normal limits and it was noticed the dcdc converter code was 0. The physician was notified regarding the possibility of a short circuit condition in the pt's lead. No add'l info has been rec'd regarding last known good diagnostics. The pt has been scheduled for full revision surgery. X-rays to evaluate the integrity of the device have not been taken. If present, an intermittent short-circuit could have potentially contributed to the pt's erratic painful stimulation event

http://www.accessdata.fda.gov/scripts/cdrh/cfdocs/cfMAUDE/detail.cfm?mdrfoi__id=1583750


Title: Re: Short circuit
Post by: dennis100 on March 26, 2012, 11:33:16 AM
Model Number 302-20
Event Date 01/01/2008
Event Type Malfunction
Event Description
Reporter indicated a vns pt had a dcdc=0 on systems diagnostics currently and in 2008; the dcdc code was 2 in 2006. The pt is currently experiencing increased nocturnal seizures. The pt is nonverbal and cannot state if stimulation is felt. A short circuit condition of the lead may be occurring. The reporter was advised to have x-rays done to assess the integrity of the vns device. Attempts for further info are in progress.

Manufacturer Narrative
Device failure is suspected.

http://www.accessdata.fda.gov/scripts/cdrh/cfdocs/cfMAUDE/detail.cfm?mdrfoi__id=1614973


Title: Re: Short circuit
Post by: dennis100 on March 26, 2012, 11:33:40 AM
Model Number 300-20
Event Date 01/06/2010
Event Type Malfunction
Event Description
Manufacturer review of vns programming history for a patient identified that a possible short circuit condition of the vns lead may be occurring due to a decreasing dcdc code. The patient was also experiencing pain at the generator site, and the vns generator was believed to be at end of service. The pain event was previously reported via mdr #1644487-2010-00239. The patient had generator replacement surgery only on (b) (6)2010. Lead impedance was checked "ok" for systems diagnostics with the new generator, but the dcdc code is not known. Attempts for further information are in progress.

Manufacturer Narrative
Conclusions: device failure is suspected, but did not cause or contribute to a death or serious injury.

http://www.accessdata.fda.gov/scripts/cdrh/cfdocs/cfMAUDE/detail.cfm?mdrfoi__id=1613613


Title: Re: Short circuit
Post by: dennis100 on March 26, 2012, 11:34:06 AM
Model Number 302-20
Event Date 11/18/2009
Event Type Malfunction
Event Description
Initial reporter indicated that their patient had a dcdc of 0 on their systems test, worsening seizures and reduced quality of life. The patient's seizures have been worsening over the last year. The dcdc 0 on their systems test was noticed in (b) (6) 2009. The patient does not take any seizure medications and no programming changes were made around the time of the reported event. It was reported that the patient does on occasions report feeling his stimulation. The patient had previously been very bright and communicative. In (b) (6) 2009, he had an eeg and it did not show more seizure activity at that time. It is believed currently the patient's seizures are over their prevns baseline rate. No fall, injury or manipulation occurred around the time the patient's dcdc 0 was noted. The patients nurse does not relate the worsening seizure control to the drop in dcdc codes on their systems test as it was occurring before the drop was recorded. The patient's vns is currently programmed on and they are going to be evaluated for a possible short circuit condition. At this time no x-rays have been performed or surgical interventions planned.

Manufacturer Narrative
Device malfunction suspected, but did not cause or contribute to a death.

http://www.accessdata.fda.gov/scripts/cdrh/cfdocs/cfMAUDE/detail.cfm?mdrfoi__id=1604137


Title: Re: Short circuit
Post by: dennis100 on March 26, 2012, 11:34:29 AM
Model Number 300-20
Event Date 01/01/2009
Event Type Malfunction
Event Description
It was reported that a vns pt experienced an increase in seizures due to unk reason. The pt's parents had not noticed the presence of cough and voice alteration with stimulation after the pt's sudden increase in seizures. Furthermore a dcdc of 0 was read at a necessary follow up with the treating neurologist in nov 2009 and x-rays along with evoked potentials and normal mode diagnostics resulted in terms of normality. The pt's generator was left on as advice was given from a company rep to maintain the device on. The treating neurologist at the time believed the increase in the pt's seizures was due to the pt's natural disease progression. The neurologist had plans to replace the vns system, but the given advice to leave the generator on changed the physician's perspective. A review of the pt's programming history indicated system diagnostics were previously of dcdc 1 and dropped to dcdc 0 in the span of approx 2 yrs (from (b)(6) 2007 to (b)(6) 2009). Additional info was received through a company rep from the treating physician. The physician indicated the pt's seizures were of unk pre-vns level at the time of the dcdc of 0 and interventions taken for the dcdc of 0 were to program the pt's device off. At the moment no surgical interventions are planned as the pt is now receiving a different drug therapy and is seizure free. Nonetheless, review of the evoked potential reading by the mfr revealed normality as expected normal pulse (a clear positive square wave followed by a charge-balanced negative phase). However, the changes in clinical symptoms at the time are likely indicative of a short circuit issue along with the consideration of a drop in dcdc code from 1 to 0.

Manufacturer Narrative
Device malfunction is suspected, but did not cause or contribute to a death or serious injury.

http://www.accessdata.fda.gov/scripts/cdrh/cfdocs/cfMAUDE/detail.cfm?mdrfoi__id=1652988


Title: Re: Short circuit
Post by: dennis100 on March 26, 2012, 11:34:54 AM
Model Number 302-30
Event Date 12/01/2009
Event Type Malfunction
Manufacturer Narrative
Device failure is suspected, but did not cause or contribute to a death or serious injury.

Event Description
It was reported to the manufacturer that a vns pt had a short circuit condition of the vns lead. The pt was in the operating room for an end of service generator replacement and when the physician tried to interrogate the new generator with the existing leads he encountered low impedance error message saying resistance was less than 200 ohms. After troubleshooting the error message did not resolve, therefore the surgeon decided to replace the leads. After the replacement when the diagnostics were performed, results were within normal limits. Good faith attempts to obtain additional info regarding the reported event and explanted lead has been unsuccessful to date.

http://www.accessdata.fda.gov/scripts/cdrh/cfdocs/cfMAUDE/detail.cfm?mdrfoi__id=1650140


Title: Re: Short circuit
Post by: dennis100 on March 26, 2012, 11:35:16 AM
Model Number 102
Event Date 02/16/2010
Event Type Injury
Event Description
Summary: it was reported that a vns patient experienced pain due to unknown reason. Furthermore, the treating psychiatrist indicated the patient was likely experiencing pain due to short circuit as the physician had received a safety alert letter regarding the issue. A review of the patient's programming history revealed the patient's dc dc code at implant was 1 and impedance was ok, but no additional diagnostics were available. Additional information was received through a company representative indicating the patient was seen by a vascular surgeon as the word vns was misinterpreted and confused for varicose veins. The vascular surgeon was not familiar with vns, but stated the patient was experiencing an increase in depression. At the moment it is unknown if the patient's depression has increased as good faith attempts to obtain additional information with the treating psychiatrist have been unsuccessful to date. Furthermore, no device anomalies are suspected at the time as there is not enough information to confirm the event of short circuit.

http://www.accessdata.fda.gov/scripts/cdrh/cfdocs/cfMAUDE/detail.cfm?mdrfoi__id=1635355


Title: Re: Short circuit
Post by: dennis100 on October 13, 2012, 05:17:22 AM
Model Number 102
Event Date 12/12/2006
Event Type  Injury  
Patient Outcome  Required Intervention  
Event Description  
It was reported that the patient had her vns explanted on (b)(6) 2012 when it was originally believed that she would be getting a replacement surgery on that date. Follow up confirmed that a replacement system was not implanted. It was mentioned that the generator may have been at end of service and that the patient did not believe the device was helping her. Product analysis on the generator was completed on (b)(6) 2012. Results showed no signs of variation in the pulse generator's output signal and demonstrated that the device provided the expected level of output current for the entire monitoring period. The pulse generator diagnostics were as expected for the programmed parameters. The generator performed according to functional specifications and no anomalies were found. Product analysis on the lead was completed on (b)(4) 2012. The lead connector had detachment at the ring/backfill interface. Both the positive and the negative coil were retracted against the connector ring assembly and in contact inside the connector boot resulting in a short circuit condition. Based on the appearance of the lead, it is believed that this condition was most likely caused during the explant procedure. Other than the above mentioned observations and typical wear and explant related observations, no other anomalies were identified in the returned lead portions. On (b)(6) 2012 a vns implanting surgeon reported that the patient came to him to get her vns removed because it had already been determined by her neurologists that the device was not working and she did not want to go to her previous surgeon. Per the surgeon, the patient also expressed that the device was giving her pain. It was reported that the patient began having pain at the site of the vns immediately after her initial surgery and that the pain radiated to her left hand as well. This occurred 24/7 and affected how the patient sat, moved, and performed day to day activities. The pain was described as a "shocking"; sensation involving the arm and the shoulder. The patient notes that she cannot hold a coffee cup or wash dishes because she has "charley horses"; of the neck along the course of the vns wire. The patient also stated that she cannot turn her neck because it feels "squeezed tight"; and her whole chest tightens up. Per the surgeon, the neurologist had turned off the vns three months prior, however despite the shocking component of the pain becoming less often; she still had a frequent pain. During the time the vns was working, the patient did not recall the pain occurring solely during stimulation time, and the seizures did not increase once the device was turned off. The surgeon was unsure if the patient's symptoms could be explained based on the vagus nerve stimulator. He indicated that there are no nerves that go from the area of the vagus nerve or the left subcutaneous anterior chest to the left hand, so he could not explain most of the patient's symptoms based on the presence of the device. In addition, the fact that the symptoms persisted even when the device was turned off was additional evidence that the patient's current symptoms were not caused by the device and that removal of the device would not make her symptoms go away. On the other hand, the patient was quite clear that her symptoms began immediately after implantation of the device, so the surgeon explained that it was possible that the surgery to implant the device could have triggered the onset of symptoms. Follow up was performed with the neurologist, however, they stated that he had not seen the patient since (b)(6) 2011 and had no information on the patient.
 
http://www.accessdata.fda.gov/scripts/cdrh/cfdocs/cfmaude/detail.cfm?mdrfoi__id=2763658  


Title: Re: Short circuit
Post by: dennis100 on June 23, 2014, 08:01:41 AM
Model Number 302-20
Device Problems Vibration; Low impedance
Event Date 09/01/2007
Event Type Malfunction
Patient Outcome Required Intervention
Event Description
As part of a retrospective complaint review associated with an investigation of low impedance events, the events in this complaint investigation were assessed for the possibility of a short-circuit condition in the implanted lead. Based on clinical symptoms and the diagnostic history of the pt's device, this file was found to be possibly related to a short-circuit condition. Reporter indicated that the pt was experiencing painful stimulation and a "vibration" of the generator in the chest area. As there are no mechanical component which could cause a vibration, it was likely muscle spasms. The event resolved when the device was disabled using the magnet, and the physician has opted to turn the device output to 0ma.

http://www.accessdata.fda.gov/scripts/cdrh/cfdocs/cfmaude/detail.cfm?mdrfoi__id=1698855


Title: Re: Short circuit
Post by: dennis100 on November 23, 2015, 09:53:26 AM
Model Number 304-20
Device Problem Low impedance
Event Date 07/30/2015
Event Type Malfunction
Manufacturer Narrative
Corrected data: initial report inadvertently did not include udi for suspect device. Udi: (b)(4).

Manufacturer Narrative

Event Description
Additional analysis was performed, which verified the short circuit condition. X-ray analysis showed that a portion of the connector ring was compressed and was making electrical contact with the connector pin. Resistance measurements between the connector pin and connector ring and between the positive and negative electrode ribbons verified the short circuit condition. The use of the clamp tool during surgery most likely compressed the connector ring to make electrical contact with the connector pin.

Event Description
Analysis identified possible surgical damage to the lead connector pin, including tool marks on the connector pin, body of the small front o-ring, and on the connector ring surface. The body of the small front o-ring appeared to be compressed, and a portion was torn. However, no device-related anomalies were identified. The device history record was reviewed for the lead, and the device performed according to all functional specifications.

Event Description
It was reported that low impedance was identified through device diagnostics during an initial implant surgery. Troubleshooting attempts were made, and the lead was identified as the issue. A test resistor was used to verify that the generator was functioning properly, which showed normal impedance the physician did not use the provided tunneler, instead using a clamp instrument on the lead pin to pull the lead through. Programming data was reviewed, which confirmed the low impedance that was identified when the lead was used. The suspect lead was received on 08/06/2015. Analysis has not been completed to date.

https://www.accessdata.fda.gov/scripts/cdrh/cfdocs/cfmaude/detail.cfm?mdrfoi__id=5022762


Title: Re: Short Circuit
Post by: dennis100 on November 29, 2015, 04:04:41 PM
Model Number 302-20
Device Problems High impedance; Inappropriate shock; Battery issue
Event Date 09/01/2014
Event Type Malfunction
Event Description
Analysis of the generator was completed 07/27/2015. A comprehensive automated electrical evaluation showed that the pulse generator performed according to functional specifications. There were no performance or any other type of adverse conditions found with the pulse generator. Analysis of the explanted lead was completed on 08/12/2015. The reported allegation of high impedance was not confirmed. No obvious anomalies were noted except for the set of setscrew marks found near the end of the connector pin indicating the lead had not been fully inserted into the cavity of the generator at one time. Continuity checks of the returned lead portions were performed, during the visual analysis, and no discontinuities were identified.

Manufacturer Narrative
Device failure is suspected, but did not cause or contribute to a death or serious injury.

Event Description
It was reported that the patient was experiencing a shocking sensation from the vns. It was reported that the patient was scheduled for generator replacement because the patient's neurologist did not know why the shocks were occurring. Clinic notes dated (b)(6) 2014 note that the patient had been complaining of left side electrical sensations when turning his neck to the left. Clinic notes dated (b)(6) 2015 note that the patient is feeling shocks and misfiring and that the vns is not working. It was noted that the patient feels a pulling on the left side of his neck and that he has been having a few seizures; however, it was also noted that the patient has not been taking medications prescribed at the last visit. Clinic notes dated (b)(6) 2015 note that the patient complains of the generator shocking him to the point of tears. The patient was seen the day prior at which time device settings were lowered which was noted to have worked to decrease the shocking sensation. It was noted that the generator is shorting out and the battery was malfunctioning and the patient would be referred for surgery to replace the battery. Further follow-up revealed that the patient was standing in his kitchen two weeks prior when he felt the device begin to stimulate. The patient reported that he normally has a choking sensation with stimulation, but this instance it did not go away. The patient reported since that time he experienced severe choking and painful stimulation. During the surgery, pre-operative diagnostics resulted in high impedance. Both the generator and lead were then replaced. The explanted devices were received for analysis. Analysis is underway, but has not been completed to date.

https://www.accessdata.fda.gov/scripts/cdrh/cfdocs/cfmaude/detail.cfm?mdrfoi__id=4922100


Title: Re: Short Circuit
Post by: dennis100 on December 01, 2015, 01:28:05 PM
Model Number 300-20
Event Date 05/12/2012
Event Type Malfunction
Manufacturer Narrative
Manufacturer reviewed x-rays of implanted device. Review of x-rays by the manufacturer revealed a gross lead discontinuity. Device failure occurred, but did not cause or contribute to a death or serious injury.

Event Description
Clinic notes dated (b)(6) 2015 note that the patient and her mother feel that the vns was injured or disconnected the year prior and that device diagnostics were within normal limits. It was noted that there was a tightness in the lead that the neurologist was concerned about. The surgeon noted that there is no unusual tightness of the lead. An x-rays assessment was received indicating that the lead wire was disconnected from the device in the left neck. It was reported that device diagnostics performed on (b)(6) 2014 were within normal limits (1704 ohms). The neurologist believes that scar tissue is the reason for the lead tightness feeling that the patient experiences. The neurologist indicated that the patient's parents have asked for the generator and lead to be replaced. X-rays were sent to manufacturer for review. X-rays identified that the lead appeared to be fractured near the electrodes. It was later reported that high impedance was observed and that revision surgery was planned. A fluoroscopy was performed by the surgeon who found that the lead could not be seen clearly and concluded that the lead may have never been connected. Recent diagnostics were found in the physician's programming system that showed that device diagnostics were within normal limits at one time which showed that the device was at one time connected. The patient was seen on (b)(6) 2015 at which time device diagnostics were within normal limits. It was reported that the device was functioning normally and was programmed back on. The cause of the diagnostics being within normal limits is a believed short circuit situation with the patient's tissue. A device decoder was performed which identified that the lead break likely occurred as early as (b)(6) 2012. The patient was referred back to surgeon. No known surgical interventions have occurred to date.

Event Description
Additional x-rays were sent to the manufacturer for review. X-rays identified that the lead appeared to be fractured near the electrodes confirming a lead break.

Manufacturer Narrative
Age at time of event; corrected data: this information was inadvertently reported incorrectly on initial mfr. Report.

https://www.accessdata.fda.gov/scripts/cdrh/cfdocs/cfmaude/detail.cfm?mdrfoi__id=4749594


Title: Re: Short Circuit
Post by: dennis100 on December 16, 2015, 10:49:37 AM
Model Number 103
Event Date 08/29/2014
Event Type Malfunction
Event Description
It was reported that the device was discarded after surgery. Therefore, analysis is unable to be completed.

Manufacturer Narrative

Event Description
It was reported that during vns implant surgery on (b)(6) 2014, the patient¿s generator was shorted and subsequently showed an end of service condition. Another generator was opened in the o. R and used for replacement. The shorted generator has not been returned to date.

https://www.accessdata.fda.gov/scripts/cdrh/cfdocs/cfmaude/detail.cfm?mdrfoi__id=4119195


Title: Re: Short Circuit
Post by: dennis100 on December 23, 2015, 01:08:35 PM
Model Number 300-20
Event Date 12/18/2013
Event Type Malfunction
Manufacturer Narrative
Device manufacturing records and programming history were reviewed. Review of manufacturing records confirmed the device met all final testing specifications prior to distribution. Device failure is suspected, but did not cause or contribute to a death or serious injury.

Event Description
On (b)(6) 2013, it was reported that system diagnostics showed dcdc=0. Device settings were noted and there had been no change in seizures (still seizure-free); however, the patient was no longer feeling the stimulation since an unknown date. The patient¿s settings were increased, but the patient still could not feel the stimulation. Diagnostics were again performed, which showed dcdc=0 on system and dcdc=1 on normal mode. It was decided at that time that the patient would be referred for lead revision due to a suspected short circuit. Clinic notes dated (b)(6) 2013 were received. Diagnostics on this date showed unclear diagnostic results; however, it is believed that the results were within normal limits with neos: yes. Attempts will be made for additional information. No other information has been received to date. Surgery is likely, but has not occurred to date.

Event Description
On (b)(6) 2014, it was reported that following an increase in settings, the patient still could not feel stimulation in the neck but could now feel stimulation in the chest. Diagnostics showed dcdc=0, but there was no ¿limit¿ output status. On (b)(6) 2014, the patient underwent surgery. A battery and lead inspection reportedly showed a lead impedance issue. The lead and generator were explanted but not replaced at this time due to significant scarring around the jugular. Additional information was received stating that surgery was performed due to short circuit condition evidenced by dcdc=0 and clinical effect of stimulation in the chest. The surgery also involved repair of the side wall of the jugular vein and a general surgeon was called in to assist. It is unknown whether the injury occurred before or during surgery. X-rays have not been taken and the patient has not been re-implanted to date. Patient manipulation or trauma is not believed to have occurred. Attempts to have the product returned for analysis were made but have been unsuccessful to date.

https://www.accessdata.fda.gov/scripts/cdrh/cfdocs/cfmaude/detail.cfm?mdrfoi__id=3570955


Title: Re: Short Circuit
Post by: dennis100 on December 26, 2015, 11:28:05 AM
Model Number 302-20
Event Date 10/10/2013
Event Type Malfunction
Event Description
Clinic notes dated (b)(6) 2013 noted that the patient had a recurrent event semiology of tonic seizures occurring at school. The generalized tonic-clonic seizure took place on (b)(6) 2013. Prior to this event, the patient had not had this seizure type since vns implant. The patient¿s eye fluttering had also continued to increase since the last visit, and several eye flutters were noted at the appointment. The patient was referred for prophylactic generator revision due to the age of the implant. The increase was believed to be associated with a decrease in vns battery strength. The vns pulse width was increased. The patient underwent generator revision on (b)(6) 2013. After the generator was replaced, subsequent diagnostics show the impedance value at 833 ohms. Diagnostics were repeated twice with impedance values at below 600 and then 673 ohms. No pre-operative diagnostics were performed. The generator was returned for analysis. Analysis is underway, but has not been completed to date.

Event Description
Product analysis of the returned generator was performed. When the device was returned, it was noted that the output current was set to 0 ma. The device output signal was monitored for more than 24-hrs, while the generator was placed in a simulated body temperature environment. Results showed no signs of variation in the pulse generator¿s output signal and demonstrated that the device provided the expected level of output current for the entire monitoring period. The pulse generator diagnostics were as expected for the programmed parameters. In addition, a comprehensive automated electrical evaluation showed that the pulse generator performed according to functional specifications. There were no performance or any other type of adverse conditions found with the pulse generator.

Manufacturer Narrative
Device manufacturing records were reviewed. Review of manufacturing records confirmed that the lead passed all functional tests prior to distribution. Device failure is suspected but did not cause or contribute to a death. Adverse event or product problem, corrected data: previously submitted mdr only showed the report as an adverse event but should have also indicated a product problem. Brand name, corrected data: previously submitted mdr indicated that the suspect medical device was the generator; however, this is actually the lead. Type of device, corrected data: previously submitted mdr indicated that the suspect medical device was the generator; however, this is actually the lead. Model #, serial #, lot #, expiration date, corrected data: previously submitted mdr indicated that the suspect medical device was the generator; however, this is actually the lead. Operator of device, corrected data: previously submitted mdr indicated that the medical professional was the user; however, this should be the patient if explanted, give date (mo/day/yr), corrected data: previously submitted mdr indicated the explant date for the generator: the updated suspect medical device (the lead) remains implanted. Device available for evaluation, corrected data: previously submitted mdr indicated the return date for the generator: the updated suspect medical device (the lead) remains implanted and has not been returned. Type of reportable event, corrected data: previously submitted mdr only showed the report as an adverse event but should have also indicated a product problem. Device manufacture date, corrected data: previously submitted mdr indicated that the suspect medical device was the generator; however, this is actually the lead.

Event Description
The information present to date suggests that a short circuit condition exists with the lead product. Review of manufacturing records confirmed that the lead passed all functional tests prior to distribution.

https://www.accessdata.fda.gov/scripts/cdrh/cfdocs/cfmaude/detail.cfm?mdrfoi__id=3474989


Title: Re: Short Circuit
Post by: dennis100 on December 29, 2015, 12:41:52 AM
Model Number 103
Event Date 07/31/2013
Event Type Malfunction
Manufacturer Narrative
End of service message seen upon interrogation of the pulse generator.

Event Description
On (b)(6) 2013, it was reported that the generator "shorted out" during the initial implant surgery. Prior to implant surgery, the generator was checked and confirmed to be functioning properly. However, during implant surgery, the manufacturer's representative observed that electrocautery was used in the pocket while the generator was in the pocket. Diagnostics were then run and found eos=yes (pulse disabled). The patient was implanted with a different generator and the "shorted out" generator was returned for product analysis. No other information has been provided.

Event Description
The generator analysis was completed on (b)(6) 2013. Burn marks were observed on the pulse generator case, indicating that the pulse generator may have been exposed to an electro-cautery tool during device implant, which may have been a contributing factor. A reset of the pulsedisable bit in the generator memory was performed to allow for an output to once again be provided by the generator for subsequent testing. The pulse generator diagnostics were as expected for the programmed parameters. A comprehensive automated electrical evaluation showed that the pulse generator performed according to functional specifications. Other than the noted condition, there were no performance or any other type of adverse condition found with the pulse generator.

https://www.accessdata.fda.gov/scripts/cdrh/cfdocs/cfmaude/detail.cfm?mdrfoi__id=3309449


Title: Re: Short Circuit
Post by: dennis100 on January 03, 2016, 12:55:59 AM
Model Number 102
Event Date 04/18/2013
Event Type Injury
Manufacturer Narrative

Event Description
It was reported that the patient went to the emergency room on (b)(6) 2013 due to suspected problems with his vns device. The patient had the magnet taped over the device to shut it off. The patient's following neurologist advised the patient's mother to have a cardiologist check the patient as the patient was having chest pain and experiencing a shocking sensation. The patient was seen by the treating neurologist and implanting surgeon on (b)(6) 2013 and it was reported that the patient was doing fine. Device diagnostics were within normal limits. However, the treating physician planned to refer the patient to neurosurgery because he felt that the device is not working properly because the patient was experiencing a shocking feeling in the chest area, even though device diagnostics were within normal limits and the vns magnet was taped over the device to disable the stimulation. The physician believed the painful stimulation was related to the device since it occurred with stimulation on-times. The mother reported that when she attempted to disable the patient's device, the magnet did not appear to turn of the device. The patient was seen by cardiology with no issues found. The neurologist reported that the patient had fallen on multiple occasions but did not have details or dates of the falls. He believes these falls may have caused trauma to the device and/or lead. The neurologist believes that the generator is defective and wants the generator replaced due to the reported pain. The patient's device was turned off on (b)(6) 2013 which resolved the patient's pain. The surgeon was planning on scheduling the patient was revision surgery as soon as possible because the patient's seizures increased since the device was turned off. The plan was to replace the generator and possibly the lead if there was an issue identified with the lead during surgery. An x-ray reportedly did not show a lead fracture. The radiology report dated (b)(6) 2013 reported that the chest x-ray was performed due to "possible electrode disruption. " the visualized leads appeared intact per the report with no evidence of fracture. The patient saw another vns treating physician on (b)(6) 2013 for a second opinion regarding the shocking sensation. Attempts for additional information, including specific diagnostic results, have been unsuccessful to date. Although surgery is likely, it has not occurred to date.

Event Description
The surgeon reported that spite of it being turned off for two weeks or so, that he was still getting shocked. The surgeon said that it was not the ¿electronics shocking him but his disease¿ ((b)(6)). The company representative reported to the surgeon that the patient¿s mother wanted the complete vns system out (generator and leads), and then a new system put in. The surgeon reported that he would not do that and if he replaced the system with a new system he would continue to be shocked. He said he would remove it but not replace it with a new system. He also said he explained this to mom very carefully. The neurologist referred the patient for a telemetry workup. Additional information received on (b)(4) 2013 revealed that the patient had been admitted in the video monitoring unit for the last 10-days and the patient did not have any epileptic seizures, but appears to have psychogenic seizures. Additionally, the patient's device has been turned off and there is still reports of shocking, which the physician feels is due to another issue with the patient and unrelated to the vns. At this time, the physician wants the vns disabled for the next two months to see if there is any decline in the patient's seizure control since it was not clear how the vns was affecting the epileptic seizures that are thought to be present.

Event Description
The generator was returned for analysis. Analysis of the generator was completed on (b)(6) 2013. In the pa lab, the device output signal was monitored for more than 24-hrs, while the generator was placed in a simulated body temperature environment. Results showed no signs of variation in the pulse generator¿s output signal and demonstrated that the device provided the expected level of output current for the entire monitoring period. The pulse generator diagnostics were as expected for the programmed parameters. The generator performed according to functional specifications. During the product analysis there were no anomalies found with the pulse generator. It was reported that the patient's generator replacement has helped significantly and the patient is no longer experiencing a shocking sensation.

Event Description
It was reported that the patient was scheduled for generator and lead replacement surgery after seeing a different surgeon. It was later reported that the patient underwent generator replacement only on (b)(6) 2013. An implant card was received indicating that the generator was replaced due to "electrical shortage". The generator is expected to be returned for analysis; however, has not yet been received.

Event Description
The patient¿s caregiver reported that the patient¿s vns device was still shocking him even though the generator was turned off. However, the patient¿s seizures became worse with the device turned off. The caregiver wants the generator and lead replaced as soon as possible. The patient¿s primary neurologist confirmed that he turned the patient¿s device back on because the patient¿s seizure became worse with the device turned off. The patient is being referred for replacement surgery. Although surgery is likely, it has not occurred to date.

Event Description
Clinic notes from the surgeon dated (b)(6) 2013 reported that the patient was seen in clinic about his "shocking" vns and rsv (respiratory syncytial virus) to sort out if the shocking was the vns ¿device electronics vs. Just having the device in place in someone with rsv. ¿ the physician suggested that the device first be turned off (both normal and magnet output current) for two months. After two months, the patient will be re-evaluated. If the shocking events persisted, the physician noted that it would not be believed to be the electronics and to consider removing the device. If the shocking goes away but with no change in seizures, they can leave off the device or remove it. If the shocking goes away and the patient needs to the device for seizures, the patient may have generator and lead replacement.

https://www.accessdata.fda.gov/scripts/cdrh/cfdocs/cfmaude/detail.cfm?mdrfoi__id=3116580


Title: Re: Short Circuit
Post by: dennis100 on January 07, 2016, 11:40:14 PM
Model Number 103
Event Date 11/23/2015
Event Type Malfunction
Event Description
It was reported that a patient's generator seemed to be depleting more quickly than expected, because her battery status icon was showing about 75% of the battery depleted only 10 days after implant. Programming data was received on (b)(6) 2015, and there was evidence of beginning of life high battery impedance that may have drained the battery more quickly than expected in the first 10% of battery life. More programming data was received on (b)(6) 2015, which indicated that the battery voltage was rebounding after the first 10% of the battery life. However, it is unknown if the high settings may have prevented the battery from rebounding to a higher voltage. The investigation determined that the battery voltage behavior was likely related to an increased duration of the high battery impedance experienced by cfx batteries during the beginning of life or an internal short that managed to "burn" itself out.

Manufacturer Narrative
(b)(4).

https://www.accessdata.fda.gov/scripts/cdrh/cfdocs/cfmaude/detail.cfm?mdrfoi__id=5312724


Title: Re: Short Circuit
Post by: dennis100 on February 02, 2016, 06:43:38 AM
Model Number 102R
Event Date 07/13/2004
Event Type Malfunction
Manufacturer Narrative
Age at time of event, corrected data: the initial report inadvertently reported the incorrect data.

Manufacturer Narrative

Event Description
It was reported that the patient would be having prophylactic generator replacement. Vns diagnostics indicated dcdc=0 since shortly following the generator implant on (b)(6) 2004. A dcdc=0 may indicate a short circuit condition however follow-up with the site found that the patient can feel stimulation at times and has been seizure-free for years. The patient's generator has been replaced and returned for analysis. Analysis of the generator found that the adhesive backfill was missing from the header. As a result, a short circuit condition was observed when the generator was tested in saline. The same result would be expected when the device is implanted in the patient and would explain the dcdc=0. Review of the programming history available to the manufacturer found that high impedance was present on the day of implant that was previously reported in manufacturer report 1644487-2004-01017. This high impedance was believed to have resolved shortly after surgery however the missing backfill issue would result in all diagnostics to show dcdc=0 instead of indicating the high lead impedance. The missing backfill is the result of a manufacturing error. The patient's new generator is now indicating high lead impedance which may be a continuation of the previous lead issue and will be housed in manufacturer report 1644487-2004-01017. No adverse events have been reported as a result of the issue.

https://www.accessdata.fda.gov/scripts/cdrh/cfdocs/cfmaude/detail.cfm?mdrfoi__id=2577640


Title: Re: Short Circuit
Post by: dennis100 on February 11, 2016, 12:12:57 PM
Model Number 302-20
Event Date 08/01/2011
Event Type Malfunction
Manufacturer Narrative
Device failure is suspected, but did not cause or contribute to a death or serious injury.

Event Description
It was reported on 02/13/2012 that the patient experienced a cluster of seizures which occurred in (b)(6) 2011. Diagnostics performed in august gave results of 840ohms and 760ohms, with intensified follow-up indicator = no. Impedance values were observed and were found to have decreased over time from 1500ohms down to 760ohms. Diagnostics were performed on (b)(6) 2012 with varying results depending on the patient's head position: with the patient's head to the left - impedance value: 1369ohms. With the patient's head to the right - impedance value: 847ohms. It is likely that the patient has a positional lead fracture which is causing the varying impedance values. There was no manipulation or trauma suspected, and the patient is non-verbal so it is unknown if the patient is experiencing any pain. It was also indicated that there were no changes in medications in last 6 months and no recent change in settings. X-rays were taken, and the patient was referred for revision. Ap and lateral chest and neck x-rays dated (b)(6) 2012 were received for the on (b)(4) 2012 and reviewed. The generator appeared to be in the left chest in a normal orientation. The filter feedthru wires appear to be intact. The electrode alignment appears to be normal. The lead at the connector pin appears to be intact. There is some lead behind the generator that could not be evaluated. No gross lead discontinuities or sharp angles can be visualized. Based on the x-rays received, no gross lead discontinuities or sharp angles appear to be present; however an unpronounced lead fracture cannot be ruled out. Additional information was received indicating that the patient's increase in seizures was below baseline. The patient underwent a revision surgery on (b)(6) 2012 and the explanted products were returned on (b)(4) 2012. Analysis is not yet complete.

Manufacturer Narrative
Device failure occurred, but did not cause or contribute to a death or serious injury.

Event Description
Product analysis on the explanted lead and generator was completed on (b)(6) 2012. An analysis was performed on the returned lead portions and a condition was observed that could potentially contribute to the reported low impedance. Abraded openings on two adjacent sections of inner tubing created a condition whereby the exposed conductive coils could come in contact with each other contributing to the :"low impedance" condition. Multiple abraded openings were found on the outer and inner silicone tubes, and most likely provided the leakage path for what appeared to be remnants of dried body fluids found inside the outer and inner silicone tubes. With the exception of the abraded inner tubing openings, the condition of the returned lead portions is consistent with those that typically exist following an explant procedure. No obvious anomalies, beyond the inner tubing openings, were noted. The setscrew marks found on the lead connector pin provide evidence that, at one point in time, a good mechanical and electrical connection was present. Continuity checks of the returned lead portions were performed, during the visual analysis, and no discontinuities were identified. Based on the findings in the product analysis lab, there is evidence to support a potential short circuit condition (low impedance). Note that since a large portion of the lead assembly (body) including the electrodes was not returned for analysis, an evaluation and resulting commentary cannot be made on that portion of the lead. Product analysis on the explanted generator was also completed. Results of diagnostic testing indicated the device was operating properly and communicated properly. Electrical test results showed that the pulse generator performed according to functional specifications.

https://www.accessdata.fda.gov/scripts/cdrh/cfdocs/cfmaude/detail.cfm?mdrfoi__id=2490039


Title: Re: Short Circuit
Post by: dennis100 on February 12, 2016, 12:45:35 AM
Model Number 102
Event Date 08/03/2004
Event Type Malfunction
Event Description
During manufacturer product analysis of a vns a generator that was replaced prophylactically, it was observed the generator was not operating according to functional specifications. The pulse generator unit failed the feed-thru capacitor tests (backup cap pos to can and backup cap neg to can). With the exception of the noted condition, there were no adverse findings that would inhibit the product from performing as intended. The most probable root cause for the backup capacitor tests was identified to be a short on the feed-thru assembly due to observed residue on the feed-thru ceramic, which is known to be related to the manufacturing process of the component. The function of the feed-thru capacitors is only to provide emi protection (if the need ever arises) and is not required to provide therapy. Manufacturer review of the generator's device history record confirmed the generator met all final testing requirements prior to distribution.

https://www.accessdata.fda.gov/scripts/cdrh/cfdocs/cfmaude/detail.cfm?mdrfoi__id=2483794


Title: Re: Short Circuit
Post by: dennis100 on February 16, 2016, 02:43:44 AM
Model Number 300-20
Event Date 01/01/2012
Event Type Malfunction
Manufacturer Narrative
Device failure is suspected to have caused the event.

Event Description
It was reported that a patient was seen by her neurologist on (b)(6) 2012 in which normal mode and systems diagnostic tests showed low impedance with a dcdc code of 0. The last time the patient was seen was in (b)(6) 2011, and the dcdc code was 2 at that time. The patient was seen by her neurologist on (b)(6) 2012 because she had experienced an increase in seizures the last few weeks and was no longer feeling stimulation during magnet mode. The neurologist suspected a short circuit condition with the dcdc code of 0 and the patient's clinical symptoms. The neurologist referred the patient for x-rays and fur surgery. No trauma was reported to the neurologist. Although surgery is likely, it has not occurred to date. Attempts for additional information from the neurologist have been unsuccessful to date. A battery life calculation was performed with the history available in the in-house database and resulted in approximately 4. 38 years until eri=yes.

https://www.accessdata.fda.gov/scripts/cdrh/cfdocs/cfmaude/detail.cfm?mdrfoi__id=2455645


Title: Re: Short Circuit
Post by: dennis100 on February 26, 2016, 03:32:50 AM
Model Number 302-20
Event Date 08/24/2011
Event Type Malfunction
Manufacturer Narrative
Device failure is suspected, but did not cause or contribute to a death or serious injury.

Event Description
Reporter indicated to the manufacturer that it is unknown on which vns diagnostics test the high lead impedance was obtained (systems or normal mode diagnostics). The patient had no known trauma and does not manipulate the vns. X-rays were not performed.

Event Description
Reporter indicated the patient was seen in clinic on (b)(6) 2012. Systems and normal mode diagnostics were within normal limits. The patient's painful stimulation in the neck resolved with a decrease in the output current from 1. 25ma to 1. 0ma. In addition, the patient has voice alteration with stimulation, indicating the intended therapy is likely being delivered. No surgery to replace the vns generator or lead is planned at this time; the family may wish to replace the generator later this year.

Event Description
Reporter indicated a vns patient was experiencing painful "stinging" stimulation in the neck that would cause headaches. The patient was referred for a surgical consult for the painful stimulation, but surgery is not planned at this time. The vns diagnostics history is reported to be currently a dcdc code = 0, indicating low impedance. As the low impedance is occurring in conjunction with the painful stimulation, a short circuit condition of the lead may be occurring. Review of previous vns diagnostics history shows a dcdc code = 3 in 2007. As this has currently dropped to a dcdc code = 0, a short circuit condition is suspected. Attempts for additional information are in progress.

Event Description
Analysis of the vns generator was completed. No anomalies were noted, and the generator performed per specifications. The generator was not at end of service.

Manufacturer Narrative
Type of report, corrected data: the initial mdr report inadvertently omitted the 30-day report designation.

Event Description
Reporter indicated the patient had vns generator replacement surgery performed on (b)(6) 2012. An implant card was also received to the manufacturer indicating diagnostics with the new vns generator and resident lead were within normal limits. The generator was returned on (b)(6) 2012 and product analysis is pending.

Event Description
All further attempts to the reporter for additional information have been unsuccessful to date. Per the patient's caregiver, the patient is to have additional vns diagnostics testing performed before seeing the surgeon again, but this has not occurred to date. In addition, the patient had seen a new neurologist in (b)(6) 2011. Lamictal medication was increased and the vns settings were changed, which resolved the painful vns stimulation and pain. It is still unknown if the dcdc = 0 result originally reported was received on a systems or normal mode diagnostics test. No surgery date has been scheduled to date.

https://www.accessdata.fda.gov/scripts/cdrh/cfdocs/cfmaude/detail.cfm?mdrfoi__id=2342431


Title: Re: Short Circuit
Post by: dennis100 on February 29, 2016, 06:27:56 AM
Model Number 300-20
Event Date 03/30/2010
Event Type Malfunction
Event Description
It was reported in the patient's clinic notes that her seizures had increased. The patient was having 25 seizures a day of myoclonic jerks and head drops. The patient's mother was concerned the vns was not working; the patient was noted to often "pull" on her stimulator. Data from this date ((b)(6) 2010), showed the device to be properly functioning; however, further review of the patient's programming history showed a drop in dcdc codes over time, suggesting a possible short circuit condition in conjunction with the increase in seizures. Attempts for further information have been unsuccessful to date.

Manufacturer Narrative
Device failure is suspected.

https://www.accessdata.fda.gov/scripts/cdrh/cfdocs/cfmaude/detail.cfm?mdrfoi__id=2321471


Title: Re: Short Circuit
Post by: dennis100 on March 02, 2016, 03:18:57 AM
Model Number 300-20
Event Date 11/11/2010
Event Type Malfunction
Event Description
During the review of the pt's programming history, it was noted that the pt had an impedance reading of 212 ohms, which would be considered to be indicative of a short circuit condition. Attempts for further information have been unsuccessful to date.

Manufacturer Narrative
Device failure is suspected, but did not cause or contribute to a death or serious injury.

https://www.accessdata.fda.gov/scripts/cdrh/cfdocs/cfmaude/detail.cfm?mdrfoi__id=2266040


Title: Re: Short Circuit
Post by: dennis100 on March 02, 2016, 03:19:31 AM
Model Number 302-20
Event Date 11/20/2008
Event Type Malfunction
Event Description
It was initially noticed while reviewing programming history in the manufacturer programming history database that the patient had an impedance value less than 600 ohms indicating the potential presence of a short-circuit condition. Diagnostics were run at later dates and were within normal limits. Good faith attempts for additional information have been unsuccessful to date.

Manufacturer Narrative
Method: analysis of programming history.

https://www.accessdata.fda.gov/scripts/cdrh/cfdocs/cfmaude/detail.cfm?mdrfoi__id=2264206


Title: Re: Short Circuit
Post by: dennis100 on March 02, 2016, 03:20:02 AM
Model Number 300-20
Event Date 08/03/2010
Event Type Malfunction
Event Description
It was noted that during a review of diagnostic history for an effectiveness check associated with a mfr investigation, the following generators were noted to have received an impedance measurement <600 ohms indicating the potential presence of a short-circuit condition. At the moment good faith attempts to obtain add'l info have been unsuccessful to date.

Manufacturer Narrative
Device malfunction is suspected, but did not cause or contribute to a death or serious injury.

https://www.accessdata.fda.gov/scripts/cdrh/cfdocs/cfmaude/detail.cfm?mdrfoi__id=2266046


Title: Re: Short Circuit
Post by: dennis100 on March 10, 2016, 04:54:25 AM
Model Number 102R
Event Date 04/23/2009
Event Type Malfunction
Event Description
The product in this file was returned for analysis during investigation in medwatch report number: 1644487-2010-00767 for a short circuit condition against the patient's implanted lead where later prior to surgery, they also had high lead impedance. Their explanted generator was returned for analysis. The header adhesive showed partial delamination on the non-logo side (lead cavity end) of the pulse generator case and the negative feed-thru wire was broken at the gold brazing, which is not typical in a surgical procedure. No evidence of body fluids were observed under the header adhesive or header. The header and adhesive were removed from the pulse generator case and feed-thru area. Tool marks were observed on the negative feed-thru brazing and wire. Visual analysis was performed on the negative feed-thru wire. Based on the analysis, the surface of the negative feed-thru wire showed extensive mechanical damage, which prevented identification of the wire fracture type. The broken negative feed-thru wire may have been a contributing factor to their high impedance. The observed break is also consistent with the last noted diagnostic test results (dc-dc code of 7). Due to the broken negative feed-thru wire, the output-monitoring and final electrical tests could not be performed. However, the pulse generator module performed according to functional specifications. Although anomalies in the header area of this generator most likely contributed to the allegations, the extensive mechanical damage sustained by the negative feed-thru wire prevented the determination of a root cause for the observed wire break condition.

Manufacturer Narrative
Device malfunction caused event but did not cause or contribute to a death or serious injury.

https://www.accessdata.fda.gov/scripts/cdrh/cfdocs/cfmaude/detail.cfm?mdrfoi__id=2118903


Title: Re: Short Circuit
Post by: dennis100 on March 10, 2016, 04:54:59 AM
Model Number 302-20
Event Date 04/14/2011
Event Type Malfunction
Event Description
It was reported by a nurse practitioner that a vns patient's system diagnostics reduced from dcdc=3 to dcdc=0 between (b)(6) 2010 and (b)(6) 2011, suspecting a low impedance/short circuit. The patient also starting having increased seizures (not above baseline) so the nurse practitioner increased his normal settings 'on time' from 30 seconds to 60 seconds. There was no manipulation or trauma to the generator or the lead and the cause for seizure increase is unknown. No x-rays were taken either. Later, patient's device was turned off to monitor patient's seizure frequency before proceeding with full vns revision as she did not know the relationship of seizure increases to vns. There was no programming/medication change prior to onset of seizure increase.

https://www.accessdata.fda.gov/scripts/cdrh/cfdocs/cfmaude/detail.cfm?mdrfoi__id=2185633


Title: Re: Short Circuit
Post by: dennis100 on March 12, 2016, 08:14:15 AM
Model Number 302-20
Event Date 04/18/2011
Event Type Malfunction
Manufacturer Narrative
Device failure is suspected, but did not cause or contribute to a death.

Event Description
On (b)(6) 2011, a vns treating physician reported that the patient's dcdc code has decreased over time from a 2 to a 1 and is now to a 0. The patient's seizure control is not good so the physician is concerned that there might be a short circuit in the vns. The patient has been referred to a surgeon for possible revision that is scheduled to occur in (b)(6) 2011. Good faith attempts for additional information from the patient's physician have been to no avail thus far. If additional information is received, it will be reported.

https://www.accessdata.fda.gov/scripts/cdrh/cfdocs/cfmaude/detail.cfm?mdrfoi__id=2097172


Title: Re: Short Circuit
Post by: dennis100 on March 22, 2016, 02:14:33 AM
Model Number 300-UNK
Event Date 11/01/2010
Event Type Malfunction
Event Description
It was initially reported through clinic notes that the vns was implanted a year ago for the pt and it helped shortly after it was implanted but the physician is not certain if it is helping now. System diagnostics showed a dcdc code of 0 which is lower than what pt had before. Pt is now having some increase in seizures. No add'l info was given. The pt is being referred for a battery replacement surgery. A short circuit condition is suspected; however, due to lack of info, this cannot be concluded. Good faith attempts to obtain add'l info has been unsuccessful till date.

https://www.accessdata.fda.gov/scripts/cdrh/cfdocs/cfmaude/detail.cfm?mdrfoi__id=1949008


Title: Re: Short Circuit
Post by: dennis100 on March 22, 2016, 02:15:00 AM
Model Number 302-30
Event Date 01/01/2010
Event Type Malfunction
Event Description
It was reported that the patient has been experiencing an increase in seizures and has not felt the normal and magnet mode stimulation for some time. The patient normally experiences voice alteration with stimulation but this no longer occurs. The neurologist increased the magnet current however, stimulation was not noted. The neurologist indicated that the dcdc codes for both the normal mode and system diagnostics have dropped to 0. Based on the clinical symptoms and the sudden change in the dcdc codes for the diagnostics, a short circuit condition is suspected. Attempts for further information are in progress.

Manufacturer Narrative
Device failure is suspected.

https://www.accessdata.fda.gov/scripts/cdrh/cfdocs/cfmaude/detail.cfm?mdrfoi__id=1948986


Title: Re: Short Circuit
Post by: dennis100 on March 23, 2016, 08:34:21 AM
Model Number 302-20
Event Date 09/13/2010
Event Type Malfunction
Manufacturer Narrative
Device failure has suspected.

Event Description
Reporter indicated via clinic notes received that the vns pt's family believed, the pt was having an increase in seizures. The pt was scheduled for replacement of her vns generator. The relationship of these seizures to pre-vns seizure levels is unk. During vns generator replacement, it was noted that some of the lead was exposed and frayed. Diagnostics taken indicated that a short circuit is suspected. A vns lead replacement also took place. The explanted products have been returned and are currently undergoing analysis. Further attempts for information are in progress.

https://www.accessdata.fda.gov/scripts/cdrh/cfdocs/cfmaude/detail.cfm?mdrfoi__id=1898656


Title: Re: Short Circuit
Post by: dennis100 on March 24, 2016, 07:00:06 AM
Model Number 300-20
Event Date 07/01/2010
Event Type Malfunction
Event Description
It was initially reported by the physician that the patient was not able to feel stimulation and his system diagnostics test likely showed a short circuit condition with a dcdc code 0. Magnet setting was raised and patient could still not feel stimulation. Patient's dcdc code dropped from 2 to 0. Patient is having an increase in seizures. Patient reported of falling down on her neck and has not felt stimulation since then and also experienced an increase in seizures. Patient is being referred for a full revision surgery. Good faith attempts to obtain additional information has been unsuccessful till date. The cause of problem is unknown at the moment. Physician believes that the event might be related to short circuit condition.

https://www.accessdata.fda.gov/scripts/cdrh/cfdocs/cfmaude/detail.cfm?mdrfoi__id=1890924


Title: Re: Short Circuit
Post by: dennis100 on March 24, 2016, 07:00:39 AM
Model Number 302-20
Event Date 09/01/2010
Event Type Malfunction
Event Description
It was initially reported by the nurse that the pt's diagnostics testing likely showed a possible short circuit condition. The sys diagnostics dcdc code dropped from 2 to 0 and pt is having a slight increase in seizures. Good faith attempts to obtain additional info has been unsuccessful till date. The cause of problem is unk at the moment.

https://www.accessdata.fda.gov/scripts/cdrh/cfdocs/cfmaude/detail.cfm?mdrfoi__id=1890923


Title: Re: Short Circuit
Post by: dennis100 on March 25, 2016, 02:03:23 AM
Model Number 302-20
Event Date 01/15/2010
Event Type Malfunction
Event Description
A letter to the editor written by the vns patient¿s father titled ¿epilepsy¿ stated that the patient¿s settings were adjusted in (b)(6) 2010. Subsequently, the patient attempted to commit suicide and was hospitalized. The device was reported to be shorted out, but the neurologist did not program off the device as it was deemed unsafe for the patient. The device was eventually programmed off on (b)(6) 2010. The letter reports that the manufacturer determined the device was randomly firing and not at the correct dose; however, this information was not provided by the manufacturer or reported to the manufacturer. No known interventions have occurred to date. Review of the available programming and diagnostic history showed normal diagnostic results through (b)(6) 2009.

Manufacturer Narrative
Review of the available programming and diagnostic history. Adverse event or product problem, corrected data: additional information indicates that the reported event was also an adverse event. Outcomes attributed to adverse event, corrected data: additional information indicates that the reported event was life-threatening and required hospitalization.

Manufacturer Narrative
Conclusions: device malfunction is suspected, but did not cause or contribute to a death or serious injury.

Event Description
It was initially reported by the physician that high lead impedance was observed during diagnostics performed. The pt's settings were lowered from 1. 50ma to 0. 75ma until a decision was made on the possible revision surgery or further steps made. The physician ordered x-rays to be taken, but it is unclear if they have been taken as a copy has not been forward to the manufacturer for analysis. There hasn't been any seizure activity to have caused the possible lead break or pin insertion as the pt has been receiving efficacy, but has been doing heavy lifting at his job, so it is unclear if this could have caused the high impedance. No further details have been made on the issue to date.

Event Description
The programming history was analyzed and decoded which identified that the high impedance first occurred on (b)(6) 2010 where the impedance value changed from 4526 ohms to 5737 ohms.

https://www.accessdata.fda.gov/scripts/cdrh/cfdocs/cfmaude/detail.cfm?mdrfoi__id=1807075


Title: Re: Short Circuit
Post by: dennis100 on March 27, 2016, 02:52:48 AM
Model Number 302-20
Event Date 05/01/2010
Event Type Malfunction
Event Description
It was reported that the pt's device showed dc/dc code of 0 on a system diagnostics test. It was also reported that the pt had an increase in seizures and was not feeling magnet stimulation. X-rays were reviewed by the manufacturer and no anomalies were noted with the device. Based on the diagnostic results, a possible short circuit condition is suspected with the lead. The pt's device was programmed off. Revision surgery is likely, but has not occurred to date. Attempts for further information have been unsuccessful to date.

https://www.accessdata.fda.gov/scripts/cdrh/cfdocs/cfmaude/detail.cfm?mdrfoi__id=1740240


Title: Re: Short Circuit
Post by: dennis100 on March 28, 2016, 05:20:19 AM
Event Date 05/01/2010
Event Type Malfunction
Event Description
It was reported that the patient's device was showing an impedance value <200 ohms on system diagnostics. It was also noted that the patient does not cough anymore with stimulation and has had an increase in seizures. A short circuit condition is suspected with the lead, but this cannot be confirmed to date. Attempts for further information have been unsuccessful to date.

https://www.accessdata.fda.gov/scripts/cdrh/cfdocs/cfmaude/detail.cfm?mdrfoi__id=1724223


Title: Re: Short Circuit
Post by: dennis100 on March 28, 2016, 05:20:57 AM
Model Number 302-20
Event Date 04/01/2010
Event Type Malfunction
Event Description
It was reported that the pt has had a slight increase in seizures recently and the dc/dc codes have decreased from 2 to 0 between visits. The relationship of the seizures to pre-vns baseline levels is unk. A short circuit condition may be present in the lead, but this cannot be confirmed at this time. Pt has been referred to surgeon for possible surgery, but no surgery has occurred to date. Attempts for further info have been unsuccessful to date.

https://www.accessdata.fda.gov/scripts/cdrh/cfdocs/cfmaude/detail.cfm?mdrfoi__id=1706871


Title: Re: Short Circuit
Post by: dennis100 on March 29, 2016, 05:25:16 AM
Model Number 300-20
Event Date 01/01/2010
Event Type Malfunction
Manufacturer Narrative
Conclusions: device failure is suspected, but did not cause or contribute to a death or serious injury.

Event Description
Reporter indicated a vns patient may have a short circuit condition of the vns lead. The vns was disabled. The dcdc code is currently 0, but was higher in the past. No trauma or device manipulation occurred. The plan of care is possible lead revision surgery, but not surgery date has been set. X-rays of the patient's vns have been requested but have not been received to date.

https://www.accessdata.fda.gov/scripts/cdrh/cfdocs/cfmaude/detail.cfm?mdrfoi__id=1626801


Title: Re: Short Circuit
Post by: dennis100 on March 30, 2016, 07:58:29 AM
Model Number 302-20
Event Date 01/01/2010
Event Type Malfunction
Event Description
It was initially reported by the nurse that they received low impedance on system diagnostics. System diagnostics results were normal on the prior visit ((b) (6)2009). Patient reported of not feeling normal or magnet stimulation the last two weeks. No patient manipulation or trauma was reported. X-rays have not been taken as yet. No additional information is received. Short circuit condition is suspected, however, there is no way to confirm this; therefore, the cause of problem is unknown at this time.

https://www.accessdata.fda.gov/scripts/cdrh/cfdocs/cfmaude/detail.cfm?mdrfoi__id=1604386


Title: Re: Short Circuit
Post by: dennis100 on March 31, 2016, 06:36:16 AM
Model Number 300-20
Event Date 10/10/2009
Event Type Malfunction
Event Description
Reporter indicated that a vns pt may have a short circuit condition of the vns lead. The pt has not felt stimulation for the previous two months and has had increased seizures that are not worse than her pre-vns baseline level. Follow up with the reporter revealed the pt has had x-rays taken and has been referred to a surgeon. The pt has had no trauma and does not manipulate the vns. Further attempts for the plan of care are in progress.

Manufacturer Narrative
Device failure is suspected, but did not cause or contribute to a death of serious injury.

https://www.accessdata.fda.gov/scripts/cdrh/cfdocs/cfmaude/detail.cfm?mdrfoi__id=1583686


Title: Re: Short Circuit
Post by: dennis100 on April 01, 2016, 02:36:00 AM
Model Number 302-20
Event Date 01/01/2009
Event Type Malfunction
Event Description
It was initially reported by the physician that the pt showed high lead impedance on a system diagnostics test. X-rays were performed and lead break was found. X-rays were not available for mfr review as per the physician's nurse. Nurse stated that no pt manipulation or trauma was reported. Pt's programming history was reviewed and it was noted that the pt had a continuous fluctuation of dcdc code on system test. This is indicative that a short circuit condition was suspected which eventually lead a lead break. Revision surgery is likely.

Manufacturer Narrative
Device failure suspected, but did not cause or contribute to a death or serious injury.

https://www.accessdata.fda.gov/scripts/cdrh/cfdocs/cfmaude/detail.cfm?mdrfoi__id=1571619


Title: Re: Short Circuit
Post by: dennis100 on April 02, 2016, 03:36:26 AM
Model Number 302-20
Event Date 09/23/2009
Event Type Malfunction
Event Description
Reporter indicated a vns pt's systems and normal mode diagnostics tests resulted in dcdc code = 0 consistently over the past several years except for a brief jump to dcdc code = 1. The pt is having no adverse events, but a possible short circuit of the lead is suspected. The pt has had no trauma and does not manipulate the vns. The pt has been referred to an ent physician for further evaluation and laryngoscopy. X-rays are not planned. The reporter will determine the plan of care following the ent consult.

https://www.accessdata.fda.gov/scripts/cdrh/cfdocs/cfmaude/detail.cfm?mdrfoi__id=1514165


Title: Re: Short Circuit
Post by: dennis100 on April 02, 2016, 03:37:01 AM
Model Number 302-30
Event Date 01/01/2008
Event Type Malfunction
Manufacturer Narrative
Analysis of programming history.

Event Description
It was reported that the patient was experiencing an increase in seizures, though he still has some seizure-free days. It is unknown if this increase is above or below pre-vns baseline. Review of the patient's diagnostic history along with the increase in seizures suggest a potential short circuit condition, though this cannot be confirmed at this time. A battery life calculation was run and shows there to be approximately -0. 68 years remaining unit eri = yes, though the patient's device can still be interrogated, which verifies that it is not at end of service yet. Attempts for further information have been unsuccessful to date.

https://www.accessdata.fda.gov/scripts/cdrh/cfdocs/cfmaude/detail.cfm?mdrfoi__id=1516742


Title: Re: Short Circuit
Post by: dennis100 on April 03, 2016, 02:12:57 AM
Model Number 302-20
Event Date 08/01/2009
Event Type Malfunction
Manufacturer Narrative
Device failure is suspected, but did not cause or contribute to a death or serious injury.

Event Description
It was reported to the manufacturer that the patient has been perceiving the delivery of stimulation to be erratic. Review of device diagnostic history revealed a fluctuation in dcdc code between 0 and 1 on system diagnostics tests. The physician was notified regarding the possibility of a short circuit condition in the patient's lead. X-rays were taken and reviewed by the patient's surgeon. According to the surgeon, the patient's lead appears intact in the x-ray view. There may have been trauma to the device site from patient falls that contributed to the reported event. The physician has opted to schedule the patient for prophylactic generator replacement for the reported event. If present, an intermittent short-circuit could have potentially contributed to the patient's erratic stimulation event.

https://www.accessdata.fda.gov/scripts/cdrh/cfdocs/cfmaude/detail.cfm?mdrfoi__id=1505063


Title: Re: Short Circuit
Post by: dennis100 on April 03, 2016, 02:13:29 AM
Model Number 302-20
Event Date 01/01/2009
Event Type Malfunction
Event Description
Reporter indicated a vns pt cannot tolerate any stimulation due to severe pain in her throat during stimulation. The pt was in a near-fatal car accident in (b) (6) 2009 where she was injured severely and in a coma. The reporter believes the vns lead was damaged as a result of the accident, and may possibly have a short circuit which could be causing the severe pain. X-rays were reviewed by the manufacturer which noted the negative electrode appeared stretched out. No gross lead discontinuities were noted. A sharp angle was noted near the lead bifurcation in the positive lead wire, and the lead area appears to have been pulled interiorly, possibly from seatbelt traction over the area as a result of the car accident. No vns diagnostics were performed after the (b) (6) 2009 accident. Diagnostics are unable to be performed currently due to the pt being unable to tolerate even minimal vns stimulation. The vns has been disabled and lead and generator revision surgery is planned.

Manufacturer Narrative
Manufacturer reviewed x-rays of implanted device. X-rays reviewed by the manufacturer, no gross lead continuities visualized.

https://www.accessdata.fda.gov/scripts/cdrh/cfdocs/cfmaude/detail.cfm?mdrfoi__id=1509900


Title: Re: Short Circuit
Post by: dennis100 on April 03, 2016, 02:14:01 AM
Model Number 302-20
Event Date 01/01/2008
Event Type Malfunction
Event Description
Reporter indicated that upon receiving a safety alert letter regarding potential short circuits in the lead, she was certain that the patient had a short circuit. The reporter had previously indicated that the patient has a shocking sensation in the neck, and had also denied that there was a shocking sensation, but that the patient felt a tightness in left pectoral region when the left arm was raised, and is now again alleging that the patient feels a shocking sensation. All attempts for more information, including programming history, so as to confirm or rule out a shor circuit, have been unsuccessful to date.

https://www.accessdata.fda.gov/scripts/cdrh/cfdocs/cfmaude/detail.cfm?mdrfoi__id=1505059


Title: Re: Short Circuit
Post by: dennis100 on April 07, 2016, 03:54:41 AM
Model Number 302-20
Event Date 09/28/2007
Event Type Malfunction
Manufacturer Narrative
Device failure is suspected, but did not cause or contribute to a death or serious injury.

Event Description
As part of a retrospective complaint review associated with an investigation of low impedance events, the events in this complaint investigation were assessed for the possibility of a short-circuit condition in the implanted lead. Based on clinical symptoms and the diagnostic history of the patient's device, this file was found to be possibly related to a short-circuit condition. It was reported that the patient was experiencing continuous pain in her neck. The event was likely related to stimulation and implantation. No interventions were taken as event was "tolerable" per patient. No further information is available.

https://www.accessdata.fda.gov/scripts/cdrh/cfdocs/cfmaude/detail.cfm?mdrfoi__id=1478415


Title: Re: Short Circuit
Post by: dennis100 on April 20, 2016, 04:01:54 AM
Model Number 300-20
Event Date 12/30/2008
Event Type Malfunction
Event Description
Reporter indicated a vns therapy patient experienced a "recent onset of gagging and choking. " the physician reviewed x-rays, which "showed no evidence of a lead fracture or disruption. " however, the physician is planning have the patient's lead replaced due to "possible short in wire that is causing neck discomfort even when vns is no low power," and the generator because "it is 6 years old. " a battery life calculation revealed the patient's generator was found to be 0. 42 years until the elective replacement indicator read "yes. " good faith attempts to obtain additional information have been unsuccessful to date.

https://www.accessdata.fda.gov/scripts/cdrh/cfdocs/cfmaude/detail.cfm?mdrfoi__id=1363447


Title: Re: Short Circuit
Post by: dennis100 on May 08, 2016, 01:13:05 AM
Model Number 102R
Event Date 05/01/2007
Event Type Malfunction
Event Description
Foreign matter, brown and black in color, was identified in the negative septum cavity, negative connector block, and from the negative connector block down the negative feed-thru lead to the can indicating that the components were exposed to body fluids. The negative connector block and negative setscrew were found pitted. Continuity measurements revealed low resistance measurement between the can and negative output. Diagnostic results indicated high impedance with a 4k ohm load resistor. Resistance measurements from the positive connector block to the can measured approximately 10m ohms, and from the negative connector block to the can measured 1m - 5m ohms as opposed to 15m ohms, indicating a short between the negative output and can. The generator failed to perform diagnostics, amplitude/resistance measurements, and final electrical tests, which was expected due to the low output amplitude and resistance measurements. The possiblity of a cored septum most likely resulted in the conditions, which would support an unintended electrical current path and a possible skin reaction event. The negative septum was not returned. However, a possible cause for the skin reaction conditoin appears to be associated with the establishment of an unintended electrical current path in the header portion of the pulse generator. Once the foreign matter was removed from the negative feed-thru and can, the generator passed all tests. The foreign matter had created an unintentional electrical current path between the negative feed-thru and can, causing the generator not to function as designed.

Manufacturer Narrative
Device malfunction occurred, but did not cause or contribute a death or serious injury.

https://www.accessdata.fda.gov/scripts/cdrh/cfdocs/cfmaude/detail.cfm?mdrfoi__id=882504


Title: Re: Short Circuit
Post by: dennis100 on June 06, 2016, 01:24:46 AM
Model Number 300-20
Device Problem Human-Device Interface Issue
Event Date 10/06/2015
Event Type Malfunction
Manufacturer Narrative

Event Description
Follow-up to the physician¿s office revealed that the patient had gained 15 kilograms since deactivation of vns. It was reported that the patient was programmed to 0. 75ma, which was where the coughing and choking stopped, prior to the device being disabled. There had been no change in quantity of seizures or stability since the device was disabled. The patient¿s family was anxious to remove the device as it was believed the device is no longer needed. The weight gain was considered positive for the patient. An increase in cognition was reported since the device was disabled. The x-rays taken did not show any device issue. Diagnostics were performed with the patient in multiple positions to rule out an issue related to the position of the device and the diagnostics were reported to be the same in multiple positions. No known surgery has occurred to-date.

Event Description
A patient reported to their physician that he could no longer feel the vns activating. The physician increased the normal output current stimulation from 2. 00ma up to 2. 25ma. The patient had an adverse reaction to this increase causing him to cough and choke. The physician then reduced settings until the patient could tolerate them. The patient later reported on a follow-up visit on (b)(6) 2015 that he had previously experienced a fall and chest trauma and that he could feel the vns activating at the generator site. Normal mode diagnostics indicated an impedance reading of lead impedance=ok, dcdc=0, near end of service=no. The physician suspected the lead had a short circuit based on the dcdc value of 0, although this result was on normal mode diagnostics rather than systems diagnostics. The device was disabled on (b)(6) 2015, and it was indicated that the patient wants to try medicine alone. X-rays were ordered by the physician, but have not been received by the manufacturer for review. A review of the available programming history in the manufacturer's database showed the last normal mode diagnostics on (b)(6) 2014 to have an impedance value of dcdc=4. Additional relevant information has not been received to-date.

https://www.accessdata.fda.gov/scripts/cdrh/cfdocs/cfmaude/detail.cfm?mdrfoi__id=5232917


Title: Re: Short Circuit
Post by: dennis100 on June 09, 2016, 01:04:45 AM
Model Number 303-20
Device Problems Circuit Failure; Loss of power
Event Date 09/07/2015
Event Type Malfunction
Event Description
It was reported that a vns patient had pain in the neck and throat, and swollen spot in the neck. It was reported that short circuit was suspected, as the dcdc value dropped from 6 to 5, to 3, to 2 and now 0. The generator was switched off. It was reported that the x-rays will be taken then sent to the manufacturer for review. Review of the available programming and diagnostic history showed normal diagnostic results through (b)(6) 2012. Review of manufacturing records confirmed that both lead and generator passed all functional tests prior to distribution. No known surgical interventions have occurred to date.

Manufacturer Narrative

Event Description
It was later reported that the vns patient had eating disorder, hoarseness, dysphagia and protrusion. Review of the available programming and diagnostic history received from the nurse showed normal diagnostic results through (b)(6) 2012. The x-rays were taken and sent to the manufacturer for review. The generator appears in the upper left chest in a normal placement. The filter feed-through wires appeared to be intact. The lead connector pin seems to be fully inserted into the generator connector block. The electrodes placement seems to be normal. One tie-down, strain relief bend were used to secure the implanted lead but not as indicated in the labeling. Part of the lead was behind the generator. No lead breaks or sharpe angles were visible on the assessed lead parts.

https://www.accessdata.fda.gov/scripts/cdrh/cfdocs/cfmaude/detail.cfm?mdrfoi__id=5123049


Title: Re: Short Circuit
Post by: dennis100 on June 18, 2016, 10:28:53 AM
Event Date 01/18/2016
Event Type Malfunction
Manufacturer Narrative

Event Description
It was reported that a patient was having an increase in seizures that was below the patient's pre-vns baseline frequency over the past few months. The patient used to have daily seizures, and then she started having several cluster seizures per day. Also, the magnet was not aborting seizures as it used to. The patient also did not cough when her settings were increased or hoarseness like she usually did. Normal mode diagnostics were performed, which resulted in dcdc code 0. However, it could not be determined if low impedance was present since system diagnostics were not performed. System diagnostics were performed, which resulted in dcdc code 0, indicating a short-circuit condition. The patient was referred for revision surgery, but no surgery has occurred to date.

https://www.accessdata.fda.gov/scripts/cdrh/cfdocs/cfmaude/detail.cfm?mdrfoi__id=5672397


Title: Re: Short Circuit
Post by: dennis100 on September 09, 2016, 04:55:29 AM
Model Number 303-20
Event Date 07/28/2016
Event Type Malfunction
Manufacturer Narrative
(b)(4).

Event Description
It was reported that low impedance was observed on vns patient's system implanted on (b)(6) 2015. The impedance was already found to be low some times before, but when the patient's device was checked in (b)(6) 2016, 3 system diagnostic tests were performed which showed impedance values of 600 ohms, 3000 ohms and again less than 600 ohms. X-ray was taken and sent to the manufacturer for review. The generator appears on the x-ray to be placed in upper chest in normal arrangement. The filter feed-through wires appears to be intact. The pin connector appears to be fully inserted. The electrodes appeared to be placed in normal arrangement. It is unable to assess the presence of the strain-relief bend and loop and if they were placed as specified by labeling. One tie-down is visible to secure the implanted lead. A portion of lead behind the generator could not be assessed. A clear lead discontinuity is visible, near the clavicle. A sharp angle is visible in the chest near the generator block connection and in that area, the lead appears to be twiddled. Based on the x-ray image, the cause for low impedance could be a short circuit in the lead part that appears to be twiddled. Further information was received from the nurse, indicating that no loss of efficacy yet but the patient recently could not perceive stimulation in magnet or normal mode. It was reported that no trauma was noted. The nurse indicated that it's unlikely that twiddling occurred as the generator is fairly deep and under a large breast. It was reported that the patient suffers from anxiety. Review of manufacturing records confirmed that both, the generator and the lead, passed all functional tests prior to distribution. No known surgical interventions have been performed to date.

https://www.accessdata.fda.gov/scripts/cdrh/cfdocs/cfmaude/detail.cfm?mdrfoi__id=5892846


Title: Re: Short Circuit
Post by: dennis100 on December 13, 2016, 09:15:13 AM
Model Number 201
Event Date 08/17/2009
Event Type Malfunction
Event Description
The reporter indicated that interrogation attempts with his new programming wand were taking a long time and that he suspected that a short might be present in the wand's serial adapter cable. Good faith attempts for product return are in progress.

https://www.accessdata.fda.gov/scripts/cdrh/cfdocs/cfmaude/detail.cfm?mdrfoi__id=1501077


Title: Re: Short Circuit
Post by: dennis100 on December 13, 2016, 09:16:17 AM
Model Number 201
Event Date 07/16/2009
Event Type Malfunction
Event Description
The reporter indicated that they believed that a short had developed in the serial adapter cable of their vns programming wand as they were unable to use the device to interrogate a pt's generator. The reporter indicated that they were unable to interrogate a vns pt's generator using a particular programming wand and that the issue was believed to be due to a short circuit in the device's serial adapter cable. The reporter also indicated that the cable looked "frayed" and that the interrogation process was successful once the wand was replaced. Good faith attempts for product return are in progress.

Manufacturer Narrative
Device failure is suspected, but did not cause or contribute to a death or serious injury.

https://www.accessdata.fda.gov/scripts/cdrh/cfdocs/cfmaude/detail.cfm?mdrfoi__id=1490574


Title: Re: Short Circuit
Post by: dennis100 on December 13, 2016, 03:13:36 PM
Model Number 201
Event Date 09/01/2009
Event Type Malfunction
Manufacturer Narrative
Device failure occurred, but did not cause or contribute to a death or serious injury.

Event Description
It was reported to manufacturer that the physician's programming wand had a short in the wire and the physician requested a new programming wand to replace the non-working device. The non-working wand was sent to manufacturer for analysis where analysis confirmed that the serial data cable, which produced communication errors, had an intermittent conductor at the db9 connector location. A known good bench serial data cable was substituted and all communication errors cleared.

https://www.accessdata.fda.gov/scripts/cdrh/cfdocs/cfmaude/detail.cfm?mdrfoi__id=1518411


Title: Re: Short Circuit
Post by: dennis100 on December 15, 2016, 09:52:25 AM
Model Number 201
Device Problems Communication or transmission issue; Dislodged or dislocated
Event Date 10/01/2009
Event Type Malfunction
Manufacturer Narrative
Device failure occurred, but did not cause or contribute to a death or serious injury.

Event Description
It was reported to the manufacturer that the site has been facing communication issues with their wand with the patient's generators. Troubleshooting did not resolve the issues. Another programming wand was used to communicate with the patient's devices successfully. The non-working programming wand was returned to the manufacturer for analysis. Analysis of the programming wand revealed that there was an intermittent conductor in the wand serial data cable which produced communication errors. A known good bench serial data cable was substituted at which time all communications errors cleared and full product functionality was restored. The strain relief grommet was observed to be dislodged that may have contributed to the intermittent condition of the conductors.

https://www.accessdata.fda.gov/scripts/cdrh/cfdocs/cfmaude/detail.cfm?mdrfoi__id=1549620


Title: Re: Short Circuit
Post by: dennis100 on December 15, 2016, 09:53:22 AM
Model Number 201
Event Date 10/08/2009
Event Type Malfunction
Manufacturer Narrative
Device failure occurred, but did not cause or contribute to a death or serious injury.

Event Description
A vns programming wand was returned for analysis without any allegations against its performance. Product analysis of the wand identified an intermittent conductor in the data serial cable, which caused communication problems. After a known good bench data serial cable was installed, the wand functioned per specifications.

https://www.accessdata.fda.gov/scripts/cdrh/cfdocs/cfmaude/detail.cfm?mdrfoi__id=1549675


Title: Re: Short Circuit
Post by: dennis100 on December 15, 2016, 09:54:06 AM
Model Number 201
Event Date 10/05/2009
Event Type Malfunction
Manufacturer Narrative
Device malfunction occurred but did not cause or contribute to a death or serious injury.

Event Description
Initial reporter indicated that they were having communication problems with their programming wand. The wand was able to successfully interrogate but was returned for product analysis. Product analysis concluded that the wand had a confirmed intermittent conductor in wand serial data cable; following replacement with a known good cable, full product functionality was restored.

https://www.accessdata.fda.gov/scripts/cdrh/cfdocs/cfmaude/detail.cfm?mdrfoi__id=1549512


Title: Re: Short Circuit
Post by: dennis100 on December 15, 2016, 09:54:53 AM
Model Number 201
Event Date 10/01/2009
Event Type Malfunction
Event Description
It was initially reported that the site was unable to communicate with multiple patients due to their programming wand. They were able to successfully use another wand with their patients. The programming wand was returned to the manufacturer for analysis. The analysis confirmed that the programming wand was having communication errors due to an intermittent conductor, conductor 3 (data ground), at the handle location. A known good bench serial data cable was substituted and all communications errors cleared.

Manufacturer Narrative
Device malfunction occurred, but did not cause or contribute to a death or serious injury.
 
https://www.accessdata.fda.gov/scripts/cdrh/cfdocs/cfmaude/detail.cfm?mdrfoi__id=1549315


Title: Re: Short Circuit
Post by: dennis100 on December 15, 2016, 09:55:51 AM
Model Number 201
Event Date 11/01/2007
Event Type Malfunction
Event Description
Initial rptr indicated that they were having issues with their programming sys with "screen freeze" events addressed in mdr report #: 1644487-2007-02279. The wand was returned for analysis with the programming sys and it was discovered that the serial data cable, which produced communication errors, had an intermittent conductor. A known good bench serial data cable was substituted and all communications errors cleared.

Manufacturer Narrative
Conclusions: device malfunction occurred, but did not cause or contribute to a death or serious injury.

https://www.accessdata.fda.gov/scripts/cdrh/cfdocs/cfmaude/detail.cfm?mdrfoi__id=977098


Title: Re: Short Circuit
Post by: dennis100 on December 15, 2016, 09:56:38 AM
Model Number 201
Event Date 12/05/2007
Event Type Malfunction
Manufacturer Narrative
Device failure occurred, but did not cause or contribute to a death or serious injury.

Event Description
It was reported to manufacturer that the site was experiencing intermittent communication problems, when attempting to interrogate vns pt's devices. Troubleshooting was performed at the site and the communication error was not replicated. The programming wand was returned to manufacturer for analysis. The analysis findings revealed that the serial data cable, which produced communication errors, had an intermittent conductor. A known good bench serial data cable was substituted, and all communications errors cleared.

https://www.accessdata.fda.gov/scripts/cdrh/cfdocs/cfmaude/detail.cfm?mdrfoi__id=973889


Title: Re: Short Circuit
Post by: dennis100 on December 15, 2016, 09:57:22 AM
Model Number 201
Event Date 01/14/2008
Event Type Malfunction
Event Description
Reporter indicated that his programming wand would not communicate during interrogation of a pt's generator. Inserting a new battery into the wand did not resolve the issue. It was determined that the generator was functioning properly as another programming wand was successfully used to interrogate the device. Reporter saw that the grommet was pulled out on the wand and the cords were frayed. Reporter was able to push the grommet back in. It also appeared that there was some sort of short in the wand as testing of the battery power showed intermittence. Product was rec'd by the mfr and analysis was performed. Visual evaluation did not confirm that the wand's cords were frayed. It was found, however, that the wand's serial data cable had an intermittent conductor, which produced the communication problems.

Manufacturer Narrative
Device failure occurred, but did not cause or contribute to a death or serious injury.

https://www.accessdata.fda.gov/scripts/cdrh/cfdocs/cfmaude/detail.cfm?mdrfoi__id=997543


Title: Re: Short Circuit
Post by: dennis100 on December 16, 2016, 04:01:08 PM
Model Number 201
Event Date 02/01/2008
Event Type Malfunction
Event Description
Initial reporter indicated that their programming wand had "multiple communication problems, they had changed the battery, but the event did not resolve. " the programming wand was returned for analysis. The serial data cable, which produced communication errors, had intermittent conductors. A known good bench serial data cable was substituted and all communications errors cleared.
Manufacturer Narrative
Device failure occurred, but did not cause or contribute to a death or serious injury.

https://www.accessdata.fda.gov/scripts/cdrh/cfdocs/cfmaude/detail.cfm?mdrfoi__id=1007464


Title: Re: Short Circuit
Post by: dennis100 on December 16, 2016, 04:02:06 PM
Model Number 201
Event Date 11/28/2007
Event Type Malfunction
Manufacturer Narrative
Device failure occurred, but did not cause or contribute to a death or serious injury.

Event Description
Product analysis was performed on a programming wand and a failure to program issue was confirmed. The serial data cable, which produced communication errors, had open and intermittent conductors. A mechanical anomaly was confirmed.

https://www.accessdata.fda.gov/scripts/cdrh/cfdocs/cfmaude/detail.cfm?mdrfoi__id=1009262


Title: Re: Short Circuit
Post by: dennis100 on December 16, 2016, 04:02:57 PM
Model Number 201
Event Date 02/01/2008
Event Type Malfunction
Manufacturer Narrative
Device failure is occurred, but did not cause or contribute to a death or serious injury.

Event Description
Reporter indicated that the programming wand was not communicating with the generator. Physician received the replacement programming wand and confirms that it is working. Product analysis was performed on the programming wand. The serial data cable, which produced communication errors, had an intermittent conductor. A visual examination identified a dislodged strain-relief grommet, rendering the strain-relief function ineffective. Analysis found that the dislodged strain relief grommet had not compromised the serial data cable connector. It is not known why the grommet became dislodged from its intended location.

https://www.accessdata.fda.gov/scripts/cdrh/cfdocs/cfmaude/detail.cfm?mdrfoi__id=1022082


Title: Re: Short Circuit
Post by: dennis100 on December 16, 2016, 04:03:44 PM
Model Number 201
Event Date 02/28/2008
Event Type Malfunction
Manufacturer Narrative
Device failure occurred, but did not cause or contribute to a death or serious injury.

Event Description
Reporter indicated that a site's programming wand could not be used to communicate with vns generators. The batteries were reported to be fine. It was reported that when another wand was substituted, communication was established successfully. Product analysis has been completed on the programming wand and it was found that the 9v battery was depleted and the serial cable had an intermittent conductor. When a known good battery and serial cable were substituted, communication could be established successfully.

https://www.accessdata.fda.gov/scripts/cdrh/cfdocs/cfmaude/detail.cfm?mdrfoi__id=1022731


Title: Re: Short Circuit
Post by: dennis100 on December 16, 2016, 04:04:29 PM
Model Number 201
Event Date 03/01/2008
Event Type  Malfunction   
Event Description
Reporter indicated that he could not successfully interrogate a pt's vns therapy generator with his programming system. Manufacturer representative troubleshooted doctor's programming system using her handheld, wand, and demo generator, and the problem was narrowed down to be the physician's programming wand. This programming wand in question was subsequently returned to manufacturer for analysis. During analysis the reported issue, failure to program, was confirmed. The serial data cable, which produced communication errors, had intermittent conductors. A known good bench serial data cable was substituted and all communications errors cleared.
 
Manufacturer Narrative
Device malfunction occurred, but did not cause or contribute to a death or serious injury.

https://www.accessdata.fda.gov/scripts/cdrh/cfdocs/cfmaude/detail.cfm?mdrfoi__id=1022717


Title: Re: Short Circuit
Post by: dennis100 on December 16, 2016, 04:05:19 PM
Model Number 201
Event Date 02/01/2008
Event Type Malfunction
Event Description
Reporter indicated a vns wand was not able to communicate during interrogation. The wand was returned and product analysis completed. The analysis revealed that the cause of the communication problems was an intermittent conductor in the serial data cable. A known good bench serial data cable was substituted and all communications errors cleared and the wand performed per specifications.
Manufacturer Narrative
Device failure occurred, but did not cause or contribute to a death or serious injury.

https://www.accessdata.fda.gov/scripts/cdrh/cfdocs/cfmaude/detail.cfm?mdrfoi__id=1022710


Title: Re: Short Circuit
Post by: dennis100 on December 19, 2016, 05:30:28 AM
Model Number 201
Event Date 03/14/2008
Event Type Malfunction
Manufacturer Narrative
Device malfunction occurred, but did not cause or contribute to a death or serious injury.

Event Description
Initial reporter indicated that they were having communication problems with their programming wand in the or. The wand would not communicate with the generator. Out of the or the wand successfully interrogated the generator. A malfunction was suspected against the programming wand. The wand was returned for analysis and the failure to program, was confirmed. The serial data cable, which produced communication errors, had an intermittent conductor. A known good bench serial data cable was substituted and all communications errors cleared.

https://www.accessdata.fda.gov/scripts/cdrh/cfdocs/cfmaude/detail.cfm?mdrfoi__id=1026513


Title: Re: Short Circuit
Post by: dennis100 on December 28, 2016, 10:52:50 AM
Model Number 201
Event Date 08/19/2008
Event Type Malfunction
Event Description
It was reported that the nurse practitioner obtained error messages on her handheld device. She returned both the handheld and programming wand to the manufacturer for analysis. After evaluating the handheld, no anomalies that support the reported complaint were observed so it was determined that the handheld device did not cause of contribute to the reported event. The programming wand was also evaluated and the issues reported by the nurse practitioner where confirmed. The cable was visually examined and no anomalies were identified. Additional analysis showed that the error originated in the serial data cable that had an intermittent conductor. The cable was replaced with a known good serial data cable and all the communication errors cleared. The wand with the new serial data cable passed all functional tests and was operating within the limits of the final electrical test requirements.

Manufacturer Narrative
Conclusions: device failure occurred, but did not cause or contribute to a death or serious injury.

https://www.accessdata.fda.gov/scripts/cdrh/cfdocs/cfmaude/detail.cfm?mdrfoi__id=1172122


Title: Re: Short Circuit
Post by: dennis100 on December 28, 2016, 10:53:25 AM
Model Number 201
Event Date 07/01/2008
Event Type Malfunction
Event Description
Mfg consultant reported that she is having issues with her wand and states "it will not work unless she holds the wand cord against the wand. She has ruled out issues with the wand battery and would like us to send her a new wand. " the wand was returned for product analysis and there was a serial adapter/cord failure. The serial data cable, which produced communication errors, had an intermittent conductor. A known good bench serial data cable was substitute and all communications errors cleared. After the serial data cable was substituted, the wand passed functional test and it was verified through consistent communication of the wand. A serial adapter cord failure was the cause of the reported event.

Manufacturer Narrative
Device malfunction occurred, but did not cause or contribute to a death or serious injury.

https://www.accessdata.fda.gov/scripts/cdrh/cfdocs/cfmaude/detail.cfm?mdrfoi__id=1105863


Title: Re: Short Circuit
Post by: dennis100 on December 28, 2016, 10:54:41 AM
Model Number 250
Event Date 07/31/2008
Event Type Malfunction
Event Description
Reporter indicated the black serial adapter cable was "shorting out". The site ruled out the programming wand handheld. Good faith attempts to obtain additional information have been unsuccessful to date.

https://www.accessdata.fda.gov/scripts/cdrh/cfdocs/cfmaude/detail.cfm?mdrfoi__id=1151025


Title: Re: Short Circuit
Post by: dennis100 on December 30, 2016, 05:43:48 PM
Model Number 201
Event Date 02/08/2016
Event Type Malfunction
Manufacturer Narrative

Event Description
It was reported on (b)(6) 2016 that a physician's programming system was unable to interrogate a demo generator. Troubleshooting was attempted. The company representative said that the wand battery had been changed, the serial cable had been swapped, and wands had been tested. Instructions were given to reposition the wand and restart the tablet. Also, it was mentioned that the data light was flickering, but then it was later stated that the light did not flicker. Since it was unknown what the actual cause of the communication issue was, a new tablet was provided to the physician since that was the alleged device causing the issue. Further clarification was received that the issue with the tablet was that it was frozen at the interrogation screen, which is why the failure to program occurred. The site had been having the issue for a few days, but no patients were affected. The tablet was received on 02/17/2016.

Event Description
Analysis was completed on the tablet and the associated programming wand on 03/07/2016. The programming wand did not communicate as received. Analysis on the test bench determined that the serial data cable, which produced communication errors, had intermittent conductors at the handle location. Additional serial data cable analysis determined that there was a conductor-to-shield short and an intermittent conductor-to-shield short. A known good bench serial data cable was substituted and all communications errors cleared. After the serial data cable was substituted, the programming wand performed according to functional specifications. No anomalies associated with the tablet performance were noted during testing using the ac adapter or the main battery with a full charge. The tablet performed according to functional specifications.

https://www.accessdata.fda.gov/scripts/cdrh/cfdocs/cfmaude/detail.cfm?mdrfoi__id=5482852


Title: Re: Short Circuit
Post by: dennis100 on January 05, 2017, 12:44:58 PM
Model Number MODEL 250
Event Date 04/26/2007
Event Type Malfunction
Manufacturer Narrative
Device malfunction suspected, but did not cause or contribute to a death or serious injury.

Event Description
Report indicated that "there was a short in the wire of the programming system" and "she wiggles the black connector and really pushes it into the handheld". New serial adaptor cable was sent to the site. Reported indicated that the programming system is now working with the new serial adaptor cable. Serial adaptor cable was not returned for analysis.

https://www.accessdata.fda.gov/scripts/cdrh/cfdocs/cfmaude/detail.cfm?mdrfoi__id=855773


Title: Re: Short Circuit
Post by: dennis100 on January 17, 2017, 03:12:14 AM
Model Number MODEL 250
Event Date 04/23/2012
Event Type Malfunction
Event Description
On (b)(6) 2012, a nurse practitioner reported that his programming handheld screen went blank in the middle of an interrogation and he was not able to get the screen to come back on. The handheld is consistently plugged in when not in use. A hard reset was performed and despite the handheld being charged it would not turn on. The battery door was confirmed to be firmly closed. The wand was reported to be working properly and the patient was able to be interrogated with another handheld without any problems. The handheld and flashcard were received by the manufacturer on (b)(6) 2012, for product analysis. Product analysis on the flashcard revealed no anomalies associated with flashcard software or databases; the flashcard and software performed according to functional specifications. Product analysis of the handheld confirmed that the device would not power on or off. The cause for this condition was an open fuse in the handheld associated with a defective serial cable that had an electrical short; vendor issue. Following replacement with known good fuse, full product functionality was restored. No further anomalies associated with the handheld were noted during testing using the ac adapter or the main battery with a full charge.

Manufacturer Narrative
Device failure occurred, but did not cause or contribute to a death or serious injury.

https://www.accessdata.fda.gov/scripts/cdrh/cfdocs/cfmaude/detail.cfm?mdrfoi__id=2579696


Title: Re: Short Circuit
Post by: dennis100 on January 18, 2017, 09:19:38 AM
Model Number MODEL 250
Event Date 02/01/2012
Event Type Malfunction
Event Description
Reporter indicated a vns dell x5 serial cable was causing intermittent communication problems. One of the teeth in the serial cable was visibly bent, and prevented a secure connection to the computer. Troubleshooting with the vns computer and programming wand identified the serial cable as the likely cause of the communication problems. Attempts for return of the serial cable are in progress.

Manufacturer Narrative
Device failure occurred, but did not cause or contribute to a death or serious injury.

Event Description
The computer serial cable was returned for analysis. During testing it was identified that the serial cable was unable to establish communication using a known good wand and handheld. The reason for the communication difficulties is associated with 2 bent pins in the dell axim connector plug; however, a cause for the condition is unknown. Once the pins were straightened, no further anomalies were identified. It was confirmed the bent pins in the handheld computer serial data cable caused a short circuit condition; following repair of the pins, full product functionality was restored.

Manufacturer Narrative
Device failure is suspected, but did not cause or contribute to a death or serious injury.

https://www.accessdata.fda.gov/scripts/cdrh/cfdocs/cfmaude/detail.cfm?mdrfoi__id=2466354


Title: Re: Short Circuit
Post by: dennis100 on January 19, 2017, 12:34:39 AM
Model


Title: Re: Short Circuit
Post by: dennis100 on January 21, 2017, 04:16:00 AM
Model Number 250
Event Date 06/06/2011
Event Type Malfunction
Event Description
It was reported that the physician¿s handheld computer would not power on when he pressed the power button. He said he kept them plugged in all the times and neither of them have been used in a week. Troubleshooting was performed, but the problem persisted. The product was returned to the mfr and underwent analysis. Upon analysis, the reported allegation was verified. The cause for the reported allegation is associated with an electrical short in the serial cable the would blow the handheld fuse when connected. Once the short was removed and the fuse was replaced, no further anomalies were identified.

Manufacturer Narrative
Device failure occurred, but did not cause or contribute to a death or serious injury.

https://www.accessdata.fda.gov/scripts/cdrh/cfdocs/cfmaude/detail.cfm?mdrfoi__id=2181408


Title: Re: Short Circuit
Post by: dennis100 on January 23, 2017, 01:28:48 AM
Event Date 01/10/2011
Event Type Malfunction
Event Description
It was reported by a vns treating physician's nurse on (b)(6) 2011 to a cyberonics regional manager in (b)(4) that a vns pt was experiencing an increase in seizures with a dcdc of 0. A battery life calculation was requested. The battery life calculation was performed on (b)(6) 2011. Based on the info provided and the parameters/diagnostic history found in the vns therapy programming history database, the battery life calculation gave approx 2. 98 yrs until the elective replacement interval. This calculation was based off info from (b)(6) 2005 through (b)(6) 2010. No anomalies were noted during this review of programming history. More info on the event was rec'd from the physician that the pt's increased seizures were not above pre-vns baseline. The physician initially attributed the increase in seizures to a possible end of life battery but after analysis thinks that a short circuit is likely since the pt is a kick boxer and a very keen body builder. The pt was sent for ap and lateral x-rays for investigation. Lead product info is not known for this pt. Further info has been requested; however no more info has been rec'd to date. Mfr is making attempts for the pt's x-rays for review.

Manufacturer Narrative
Device failure is suspected, but did not cause or contribute to a death or serious injury.

https://www.accessdata.fda.gov/scripts/cdrh/cfdocs/cfmaude/detail.cfm?mdrfoi__id=2024861


Title: Re: Short Circuit
Post by: dennis100 on January 27, 2017, 08:57:56 AM
Model Number 250
Event Date 06/21/2010
Event Type Malfunction
Event Description
Initial reporter indicated to their vns consultant that their (b)(6) handheld computer may have a short. It is unk if the issue is with the ac adapter cable or the serial adapter cable or the serial adapter cable. Good faith attempts are being made to have the products returned for analysis.

https://www.accessdata.fda.gov/scripts/cdrh/cfdocs/cfmaude/detail.cfm?mdrfoi__id=1765184


Title: Re: Short Circuit
Post by: dennis100 on January 28, 2017, 03:10:48 AM
Model Number 250
Event Date 05/01/2010
Event Type Malfunction
Event Description
It was reported to mfr that the neurologist was having some trouble with interrogating vns pts, as the device would interrogate sometimes and would not sometimes. Troubleshooting did resolve the issue; however, the physician wanted a new programming system. The old programming system was returned to mfr for analysis. During the analysis, it was identified that the serial cable was defective. The defective serial cable prevented the handheld from establishing communication. A visual analysis of the serial cable identified a short between the transmit and the receive wires. Once the short was removed, no further anomalies were identified.

Manufacturer Narrative
Device failure occurred, but did not cause or contribute to a death or serious injury.

https://www.accessdata.fda.gov/scripts/cdrh/cfdocs/cfmaude/detail.cfm?mdrfoi__id=1774446


Title: Re: Short Circuit
Post by: dennis100 on January 30, 2017, 02:37:59 AM
Model Number 201
Event Date 12/01/2008
Event Type Malfunction
Event Description
It was reported that the site was having problem interrogating the patient's device and kept getting message "failed to receive data". The site believed that there might be some short somewhere in the product since it would work only if held in certain position. New programming system was sent to the site and the old programming system is currently undergoing product analysis.

https://www.accessdata.fda.gov/scripts/cdrh/cfdocs/cfmaude/detail.cfm?mdrfoi__id=1343322


Title: Re: Short Circuit
Post by: dennis100 on February 01, 2017, 03:24:12 AM
Model Number 201
Event Date 06/26/2008
Event Type Malfunction
Manufacturer Narrative
Device failure suspected, but did not cause or contribute to death or serious injury.

Event Description
Reporter indicated that a site's programming wand had "a short in it" and was not working properly. It was reported that the battery was replaced, but the wand still would not work.

https://www.accessdata.fda.gov/scripts/cdrh/cfdocs/cfmaude/detail.cfm?mdrfoi__id=1182623


Title: Re: Short Circuit
Post by: dennis100 on February 04, 2017, 03:39:57 AM
Model Number MODEL 250
Event Date 02/01/2007
Event Type Malfunction
Manufacturer Narrative
Device malfunction occurred, but did not cause or contribute to a death or serious injury.

Event Description
Reporter indicated that his vns therapy programming handheld was malfunctioning, in that it was unable to recharge in order to be of use. Handheld and accompanying serial cable were returned to manufacturer for product analysis. An analysis was performed and the cause for the reported complaint was found to be associated with a defective serial cable. During the analysis, it was identified that the returned serial cable had an electrical short caused by an exposed shield wire in the dell axim connector plug hood, and this was causing the handheld to blow a fuse. Once the exposed wires were removed, no further anomalies associated with the handheld or serial cable performance were noted during testing using the ac adapter or the main battery with a full charge.

https://www.accessdata.fda.gov/scripts/cdrh/cfdocs/cfmaude/detail.cfm?mdrfoi__id=902187


Title: Re: Short Circuit
Post by: dennis100 on February 05, 2017, 01:59:11 AM
Model Number MODEL 250
Event Date 04/01/2007
Event Type Malfunction
Event Description
Reporter indicated that the site's laptop power cord was sparking. The product was returned for analysis. Product analysis identified that the positive and negative output connections of the power supply to the pc were shorted together. No other anomalies were noted.

Manufacturer Narrative
Device malfunction occurred but did not cause or contribute to a death or serious injury.

https://www.accessdata.fda.gov/scripts/cdrh/cfdocs/cfmaude/detail.cfm?mdrfoi__id=852318


Title: Re: Short Circuit
Post by: dennis100 on February 10, 2017, 04:04:45 AM
Device Problems Mechanical issue; Low impedance
Event Date 01/05/2017
Event Type Malfunction
Event Description
During a prophylactic generator replacement, the company representative observed the surgeon place "something plastic" around the lead. It was as if the surgeon was trying to repair the lead. The diagnostics prior to and after the generator replacement was within normal limits and the reason for the repair is unknown. Per company representative, the surgeon was worried about the lead in someway. Company representative was able to see the lead when performing diagnostics after the event. Per company representative, it looked normal and she did not notice any obvious issues. The surgeon clipped something around the lead (like a tube around the lead). The surgeon also took pictures of the lead. The surgeon did not provide any information on what was done or the reason. There were no reported problems with the patient or lead. A review of the programming and diagnostic data for the explanted generator shows that the dc code dropped from 3 to 0 in system diagnostic tests, which may be indicative of low impedance due to a possible short circuit condition.

https://www.accessdata.fda.gov/scripts/cdrh/cfdocs/cfmaude/detail.cfm?mdrfoi__id=6288741&pc=LYJ


Title: Re: Short Circuit
Post by: dennis100 on February 17, 2017, 01:27:56 AM
Event Date 02/18/2011
Event Type Malfunction
Manufacturer Narrative
Mfr reviewed x-rays of implanted device. Review of x-rays by the mfr revealed a gross lead discontinuity. Device failure occurred, but did not cause or contribute to a death or serious injury.

Event Description
It was reported that high impedance was found upon interrogation of the pt's vns. The pt stated that he had not been able to feel stimulation since a week prior to the office visit. The pt's vns has been disabled. X-rays were taken and forwarded to the mfr. Review of the x-rays confirmed a 1. 5-2. 5 cm lead break was present in the lower neck. It is unk if any trauma or manipulation contributed to the break. Review of the pt's programming history available to mfr found that the system diagnostics dcdc codes had previously been fluctuating from 2 to 0 possibly indicating an intermittent short circuit that may have developed into the lead fracture. Surgery to replace the pt's vns lead and generator is likely.

https://www.accessdata.fda.gov/scripts/cdrh/cfdocs/cfmaude/detail.cfm?mdrfoi__id=2041427


Title: Re: Short Circuit
Post by: dennis100 on February 19, 2017, 02:27:23 AM
Device Problem Migration of device or device component
Event Date 11/01/2013
Event Type Injury
Event Description
It was later reported that the patient has ¿burn marks¿ over her lead. Good faith attempts for further information from the physician have been unsuccessful.

Event Description
A provider reported that the patient called her to schedule an appointment to check on her vns which since (b)(6) (2015) is causing burn marks. Attempts for additional relevant information have been unsuccessful to date.

Event Description
It was reported that the patient¿s left side of the neck is swollen from behind her left ear to down her neck, and that when she leans on her left side, she feels the battery sliding down underneath her axilla. It was reported that this has been going on for a year on and off and the welling would come and go. The patient reported that it started just prior to her cabg last year, but has worsened since that surgery. She said for the last week, it has remained swollen and she is coughing a bit of blood from her throat. The patient now wants the device removed. The patient saw a cardiologist and she doesn¿t have jvd, but the cardiologist stated that possible the lead was eroding the vocal cord area. The patient stated that she has had an mi and cva this past (b)(6) 2014. Per the patient¿s primary care physician, she does not need to see an ear, nose, and throat physician. However, the patient is still having neck swelling on the left side of her neck. Although surgery is likely, it has not occurred to date.

Event Description
On (b)(6) 2015 the patient reported that he is having serious problems with the vns. The patient later reported that she is still having neck pain and swelling in the left side of the neck, feeling vibration and pulsing. She also stated that when she places the magnet over the device, she feels that stimulation is stronger. She also coughed up some blood.

Event Description
The patient indicated that she feels her lead has moved, is wrapped around her esophagus, is choking her and causing throat pain. She stated that she has continuous voice alteration but no longer feels device stimulation since the time of her last interrogation 2 months prior. She stated she has coughs up blood and has a tight feeling in her chest. She stated that her generator is under her armpit. She indicated her neurologist will be speaking with her other providers, including her cardiologist, for clearance to replace her generator and lead. Attempts for additional relevant information have been unsuccessful to date. No known surgical interventions have occurred to date.

Event Description
Information was received from two of the patient's physicians. The first physician indicated the last device check was on (b)(6) 2015 showing normal battery status, normal lead impedance and no vns parameters were altered. The physician indicated that the patient has not reported any of the prior symptoms to him. The second physician indicated the last device check was (b)(6) 2015 and the device battery was indicated to be at end of service, lead impedance was ok and no parameters were changed. He indicated that that patient had reported dysphagia and throat pain but none of the other prior symptoms. No specific interventions were undertaken. Clinic notes were subsequently received for the (b)(6) 2015 office visit which indicated that the device would be replaced due to end of service. The notes indicated that the vns give her trouble with breathing but no specific intervention is referenced. The patient subsequently called the manufacturer and reported that her seizures were worse than before vns. The patient underwent pulse generator replacement on (b)(6) 2015 however high lead impedance was detected when the indwelling lead was connected with the new pulse generator despite repeated removals and insertions. The surgeon elected not to replace the lead during the surgery. Post-implant lead impedance also measured high. Lead impedance with the prior pulse generator was normal. Review of prior programming and diagnostic data reveals fluctuating lead impedance suggesting an intermittent short circuit condition. A battery life calculation using the available programming history showed approximately 0. 2 remaining until neos = yes. No known additional surgical interventions have occurred to date.

Event Description
Operative notes containing a record of the pulse generator replacement on (b)(6) 2015, during which high impedance was observed following connection of the new generator to the indwelling lead, were received. The operative notes state that it was suspected that the high impedance measurement may possibly be due to emi from surrounding medical devices and was therefore left in place for interrogation in the postanesthesia care unit.

Manufacturer Narrative

Event Description
Information was received indicating that the patient was scheduled for lead revision surgery. The patient subsequently reported that she was hospitalized due to multiple seizures and stated she was experiencing unusual seizures. The patient underwent surgery for the high impedance condition as reported and described in mfr. Report # 1644487-2016-00375.

https://www.accessdata.fda.gov/scripts/cdrh/cfdocs/cfmaude/detail.cfm?mdrfoi__id=4334258


Title: Re: Short Circuit
Post by: dennis100 on February 20, 2017, 07:41:23 AM
Model Number 302-XX
Event Date 01/01/2011
Event Type Malfunction
Event Description
It was reported that a dc/dc code of 0 was obtained on system diagnostics. The pt was also experiencing an increase in seizures and was not feeling normal or magnet mode stimulation. It was also reported that the pt had a fall approx 6 months ago. Based on this, short circuit condition is suspected with the lead. X-rays of the device were reviewed by the mfr, but no anomalies were noted. Attempts for further info have been unsuccessful to date.

Manufacturer Narrative
Mfr reviewed x-rays of implanted device. X-rays reviewed by the mfr, no gross lead discontinuities visualized. Device failure is suspected.

https://www.accessdata.fda.gov/scripts/cdrh/cfdocs/cfmaude/detail.cfm?mdrfoi__id=2024761


Title: Re: Short Circuit
Post by: dennis100 on March 02, 2017, 12:25:12 AM
Model Number 300-20
Event Date 11/22/2010
Event Type Malfunction
Event Description
It was initially by a company rep reported that a vns pt was to undergo battery replacement due to unk reason. The company rep followed up with the office of the treating neurologist and found that in (b)(6) 2004, system diagnostics were ok dcdc=0. The patient reports an increase in seizures (still below pre-vns baseline) and feels very tired. Moreover, the patient stated that he feels like when his last battery became near end of service as there is also a feeling of pinching in his neck near the leads and stimulation is not as strong as before. Info in the mfr's programming history revealed that a system diagnostics on (b)(6) 2004, which was ok, dcdc=2. No add'l diagnostics were available at the time. Based on info received to date, a short circuit condition is suspected based on clinical symptoms, however, no conclusion can be drawn at the time.

https://www.accessdata.fda.gov/scripts/cdrh/cfdocs/cfmaude/detail.cfm?mdrfoi__id=1956833


Title: Re: Short Circuit
Post by: dennis100 on March 04, 2017, 10:15:44 AM
Model Number MODEL 250
Event Date 12/10/2014
Event Type Malfunction
Event Description
Product information received.

Event Description
It was reported that the physician's handheld was not charging and it was believed that the cable had a short in it. The nurse reported that the handheld was able to be charged if the cord is wrapped around the plug. A new charging cable was provided to the physician's office. The charging cable is expected to be returned for analysis, but has not been received to date.

https://www.accessdata.fda.gov/scripts/cdrh/cfdocs/cfmaude/detail.cfm?mdrfoi__id=4393789


Title: Re: Short Circuit
Post by: dennis100 on March 10, 2017, 04:32:19 AM
Model Number 300-20
Device Problem Low impedance
Event Date 10/18/2010
Event Type Malfunction
Event Description
It was reported that a patient was having generator replacement surgery due to normal battery depletion, and low impedance was identified during diagnostics. The surgeon used the test resistor in the new generator, and the impedance was within normal limits. The lead was not replaced at that time. Programming history indicated that there could have been a short circuit condition in the lead with the previous generator. No further surgical intervention has occurred to date.

https://www.accessdata.fda.gov/scripts/cdrh/cfdocs/cfmaude/detail.cfm?mdrfoi__id=6342618


Title: Re: Short Circuit
Post by: dennis100 on April 18, 2017, 10:56:43 PM
Model Number 300-20
Device Problem Low impedance
Event Date 12/13/2016
Event Type Malfunction
Manufacturer Narrative
(b)(4).

Event Description
Information was received indicating that the patient was not feeling stimulation like she did before. She was now feeling pain in her ear and jaw when stimulation was delivered along with an increase in gagging and choking sensations. The patient also reported that she was experiencing a shocking sensation when she turned her head to the right occasionally which resulted itching at the electrode site. The patient also reported that the muscles in her neck would tense up for 30 seconds and then relax. The patient's generator was disabled and the tension resolved. Diagnostics showed that the impedance on the patient's generator was at dcdc 0, which could be indicative of a short circuit issue under certain circumstances. The patient then had her device prophylactically replaced in (b)(6) 2017. No additional relevant information has been received to date. The explanted generator and lead have not been received to date.

https://www.accessdata.fda.gov/scripts/cdrh/cfdocs/cfmaude/detail.cfm?mdrfoi__id=6404233


Title: Re: Short Circuit
Post by: dennis100 on April 24, 2017, 03:32:41 AM
Model Number 302-20
Event Date 09/01/2009
Event Type Malfunction
Manufacturer Narrative
Device failure is suspected, but did not cause or contribute to a death or serious injury.

Event Description
It was initially reported by the physician that patient showed high lead impedance with lead impedance 7116 ohms. Normal mode showed ok, lead impedance 6993 ohms. Surgeon had ordered x-rays and treating physician wanted total revision because patient had a hard fall after prophylactic battery replacement surgery in (b) (6)2009. Follow-up with the company rep revealed that the patient had a full revision surgery. It was indicated that the last good diagnostics were obtained at the time of initial battery replacement surgery ((b) (6)2009) which showed everything within normal limit. Company rep stated that the treating physician believed that the reason for high lead impedance was due to a fall which might have caused the lead to break, however, the surgeon indicated that the reason was due to a build of a lot of scar tissue around the electrode region. She indicated that x-rays were taken, and it did not show any lead break. X-rays were not available for manufacture review. Lead was discarded by the hospital since they were torn into pieces at the time of revision surgery. The surgeon did not notice any break on the lead while removing it but he did notice a lot scar tissue around the electrode region. Patient's previous generator programming history was reviewed and it was observed that the dcdc code had dropped to 0. Given the fact that the dcdc code had dropped from 2 to 0, it is suspected that a short circuit condition likely existed which eventually lead to a lead fracture. It is unlikely that fibrosis could be a part of the high lead impedance given that the dcdc code cannot jump from a 0 to such high ohms value unless there is a lead failure.

https://www.accessdata.fda.gov/scripts/cdrh/cfdocs/cfmaude/detail.cfm?mdrfoi__id=1581033


Title: Re: Short Circuit
Post by: dennis100 on May 01, 2017, 12:23:10 AM
Model Number 302-20
Event Date 06/27/2014
Event Type Malfunction
Event Description
During prophylactic generator replacement it was reported that prior to the surgery low impedance (668 ohms) was observed. The generator pocket was opened and low impedance (322 ohms) was again observed. It was reported that fluid was observed inside the lead wire. It was reported that lead replacement would be performed at a later date. The generator was received for analysis on (b)(4) 2014. Analysis is underway, but has not been completed to date. No known surgical interventions have been performed to date.

Manufacturer Narrative
Date of this report, corrected data: the initial manufacturer report inadvertently provided an incorrect aware date. The aware date for the initial report is 07/11/2014. Date received by manufacturer, corrected data: the initial manufacturer report inadvertently provided an incorrect aware date. The aware date for the initial report is 07/11/2014.

Event Description
Additional information was received stating that the vns patient underwent generator and lead replacement surgery on (b)(6) 2015. The explanted lead was returned to the manufacturer for analysis which confirmed openings in both the inner tubing sections in adjacent areas that exposed the conductive quadfilar coils, creating an intermittent short-circuit condition. The abraded openings and slice mark found on the outer silicone tubing most likely provided the leakage path for the dried remnants of what appeared to have once been body fluids found inside the outer silicone tubing. The abraded openings found on the inner silicone tubes most likely provided the leakage path for the dried remnants of what appeared to have once been body fluids found inside the inner silicone tubes. The generator replacement surgery on (b)(6) 2015 was reported in manufacturer report #1644487-2015-04111.

Event Description
Analysis of the returned generator was completed. There were no performance or any other type of adverse conditions found with the pulse generator. The pulse generator diagnostics were as expected for the programmed parameters. A comprehensive automated electrical evaluation showed that the pulse generator performed according to functional specifications.

Manufacturer Narrative
Device failure occurred, but did not cause or contribute to death or serious injury.

https://www.accessdata.fda.gov/scripts/cdrh/cfdocs/cfmaude/detail.cfm?mdrfoi__id=3994857


Title: Re: Short Circuit
Post by: dennis100 on May 01, 2017, 12:24:08 AM
Model Number MODEL 250
Event Date 07/11/2014
Event Type Malfunction
Manufacturer Narrative

Manufacturer Narrative
Evaluation codes: no device failure occurred that would contribute to the computer powering down during use. User interface caused the crack in the screen; however, the crack did not inhibit use of the computer.

Event Description
Analysis of returned tablet device was completed. A visual inspection of the tablet verified that the display was cracked. No anomalies associated with the software or battery was identified during the analysis.

Manufacturer Narrative
Device failure occurred, but did not cause or contribute to death or serious injury.

Event Description
It was reported that during surgery, the tablet kept shorting out and would power down while attempting device interrogation. A second programming tablet was used to successfully interrogate that patient's device. It was reported that the tablet had been accidentally dropped some time ago which caused a small crack in the screen, but this was not believed to cause the sudden power down. The programming tablet was received for analysis. Analysis is underway, but has not been completed to date.

https://www.accessdata.fda.gov/scripts/cdrh/cfdocs/cfmaude/detail.cfm?mdrfoi__id=3995031


Title: Re: Short Circuit
Post by: dennis100 on May 03, 2017, 12:21:53 AM
Model Number 302-30
Event Date 11/26/2014
Event Type Malfunction
Manufacturer Narrative
Device failure is suspected, but did not cause or contribute to a death or serious injury.

Event Description
On (b)(4) 2014, product analysis was completed on the lead which confirmed opening of both inner tubing sections in adjacent areas, exposing conductive quadfilar coils and creating a potential short-circuit condition. Small portions of the (+) white and (-) green inner silicone tubes and quadfilar were not returned for analysis; therefore, a complete evaluation could not be performed on the entire lead product. During the visual analysis of the returned 31mm portion, abraded openings were observed on both of the inner silicone tubes, past the electrode bifurcation, and both of the quadfilar coils appeared to be exposed. During the visual analysis of the returned 3mm portion the (+) white electrode ribbon appeared to be embedded in what appeared to be remnants of dried body tissue. This condition may have prevented the (+) white electrode ribbon from coming in contact with the vagus nerve. The abraded opening found on the outer silicone tubing and the cut ends that were made during the explanted process, most likely provided the leakage path for the dried remnants of what appeared to have once been body fluids inside the outer silicone tubing. With the exception of the observed tissue-covered (+) white electrode ribbon and the inner tubing abraded openings, the condition of the returned lead portions is consistent with conditions that typically exist following an explant procedure. No other obvious anomalies were noted except for the half sets of setscrew marks found near the end of the connector pin indicating the lead had not been fully inserted into the cavity of the generator at one time. Additional setscrew marks found on the connector pin provide evidence that, at one point in time, a good mechanical and electrical connection was present. Continuity checks of the returned lead portions were performed, during the visual analysis, with no discontinuities identified. The positive electrode condition may have contributed to the reported high impedance. Product analysis was completed on the generator on (b)(4) 2014. The end of service condition was determined to be the result of normal battery depletion. The depletion was an expected event as determined by blc and battery voltage measurement. The module performed according to functional specifications; there was no condition noted during the product analysis evaluation that would suggest any anomaly with the device.

Event Description
On (b)(6) 2014, it was reported that the patient was referred for generator replacement due to battery depletion and that prior to the replacement, system diagnostics were performed on the existing generator and results were normal. However, when the new generator was attached to the leads, the impedance was high. The lead was disconnected and re-inserted, and the impedance was high again. The test resistor was connected to the generator and the impedance was normal. The physician re-attached the generator to the lead and the impedance was then low. A new generator was then connected to the lead and the impedance was high again. The physician therefore replaced the lead as well. The explanted lead and generator were received for product analysis on (b)(6) 2014. Product analysis is still underway and has not yet been completed.

Manufacturer Narrative
Device failure occurred, but did not cause or contribute to a death or serious injury.

https://www.accessdata.fda.gov/scripts/cdrh/cfdocs/cfmaude/detail.cfm?mdrfoi__id=4334261


Title: Re: Short Circuit
Post by: dennis100 on May 10, 2017, 12:38:20 AM
Model Number 300-20
Event Date 05/01/2014
Event Type Malfunction
Event Description
Analysis of the returned lead portion was completed and confirmed lead discontinuity. Abraded openings of both inner tubing sections were found. There is evidence to suggest that both coils were in contact with each other, leading to a potential short circuit condition.

Manufacturer Narrative
Device failure is suspected, but did not cause or contribute to a death or serious injury.

Event Description
The slice mark and abraded openings found on the outer silicone tubing and the cut ends that were made during the explanted process, most likely provided the leakage path for the dried remnants of what appeared to have once been body fluids found inside the outer silicone tubing. The abraded openings found on the inner silicone tubes and the cut ends that were made during the explanted process, most likely provided the leakage path for the dried remnants of what appeared to have once been body fluids found inside the inner silicone tubes.

Event Description
It was reported that the vns patient¿s device was tested during an office visit on (b)(6) 2014 and diagnostic results revealed low impedance. The patient¿s device settings were increased but the patient did not exhibit any signs of receiving therapy. The physician¿s handheld device showed that low impedance was first observed at generator replacement surgery on (b)(6) 2014. The device impedance value fluctuated between < 600 ohms and 869 ohms since the replacement procedure. It was noted that the patient¿s previous generator showed low impedance (dc dc ¿ 0) prior to replacement. The physician stated that the patient had been experiencing an increase in seizures since (b)(6) 2014. An implant card was received indicating that the patient underwent generator and lead replacement surgery on (b)(6) 2014 due to lead discontinuity. The surgeon observed a lead break during explant. The explanted generator and lead were returned to the manufacturer for analysis. There were no performance or any other type of adverse conditions found with the pulse generator. Various electrical loads were attached to the generator and results of diagnostic tests demonstrate that accurate resistance measurements were obtained in all instances. Monitoring of the device output signal showed no signs of variation in the pulse generator¿s output signal and demonstrated that the device provided the expected level of output current. In addition, a comprehensive automated electrical evaluation showed that the pulse generator performed according to functional specifications. Analysis of the returned lead portion is currently underway.

Manufacturer Narrative
Device failure occurred, but did not cause or contribute to death.

Manufacturer Narrative
Describe event or problem, corrected data: the supplemental report #1 inadvertently did not report this data.

Manufacturer Narrative
Device manufacture date, corrected data: the supplemental report #2 inadvertently did not report this data.

https://www.accessdata.fda.gov/scripts/cdrh/cfdocs/cfmaude/detail.cfm?mdrfoi__id=4195520


Title: Re: Short Circuit
Post by: dennis100 on May 23, 2017, 12:58:16 AM
Model Number 302-20
Event Date 01/01/2008
Event Type  Malfunction   
Event Description 
Reporter indicated that patient had a "broken lead = short causing loe and left chest wall pain. Was sent to surgeon to repair it. " patient underwent generator and lead replacement. Three good faith attempts were made with this physician to obtain further information. No further information has been received. Explanted leads were discarded by hospital therefore product analysis cannot be performed.
 
https://www.accessdata.fda.gov/scripts/cdrh/cfdocs/cfmaude/detail.cfm?mdrfoi__id=1030358


Title: Re: Short Circuit
Post by: dennis100 on June 02, 2017, 12:24:26 AM
Model Number 201
Event Date 07/24/2009
Event Type  Malfunction   
Manufacturer Narrative 
Device failure occurred, but did not cause or contribute to a death or serious injury.
 
Event Description 
It was reported that the site's wand had a short and was unable to be used. When the physician shook the cord, it would work for a second. Troubleshooting was performed, but the problem persisted. Product was returned to the manufacturer for analysis. Upon analysis, it was found that the battery cable had an intermittent connection at the positive battery connector; thereby, causing intermittent power to the device. After the positive battery cable connection was secured, the device performed according to specifications. No other anomalies were noted with the device.
 
https://www.accessdata.fda.gov/scripts/cdrh/cfdocs/cfmaude/detail.cfm?mdrfoi__id=1491977


Title: Re: Short Circuit
Post by: dennis100 on June 04, 2017, 07:53:30 AM
Event Date 01/01/2009
Event Type Malfunction
Event Description
It was reported that the patient was experiencing a slight increase in seizures (below pre-vns baseline), she can no longer feel stimulation, and her voice does not change like it used to with stimulation. The magnet still aborts seizures, however. Diagnostics resulted in dc/dc code = 0. Based on the information received, a short circuit condition is suspected with the lead. No patient manipulation or trauma is suspected, but the patient has been under a lot of stress lately. Attempts for further information have been unsuccessful to date.

Manufacturer Narrative
Device failure is suspected, but did not cause or contribute to a death or serious injury.

https://www.accessdata.fda.gov/scripts/cdrh/cfdocs/cfmaude/detail.cfm?mdrfoi__id=1497723


Title: Re: Short Circuit
Post by: dennis100 on June 05, 2017, 01:25:03 AM
Model Number 302-20
Event Date 10/01/2009
Event Type  Malfunction   
Event Description 
It was reported to the mfr that the vns pt has began experiencing a slight increase in seizure activity not above pre-vns baseline. Review of programming history revealed that system diagnostics test performed on the pt's device showed a dcdc code of zero. If present, an intermittent short-circuit could have potentially contributed to the pt's slight increase in seizure activity. Good faith attempts to obtain additional info regarding the reported event are underway.
 
Manufacturer Narrative 
Device failure is suspected, but did not cause or contribute to a death or serious injury.
 
https://www.accessdata.fda.gov/scripts/cdrh/cfdocs/cfmaude/detail.cfm?mdrfoi__id=1533077


Title: Re: Short Circuit
Post by: dennis100 on June 06, 2017, 12:20:12 AM
Model Number 302-20
Event Date 01/01/2009
Event Type  Malfunction   
Event Description 
It was reported that the patient has been having an increase in seizures for the last four months, but the relationship to pre-vns baseline levels is unknown. The patient does not currently have a vns physician who is following him, so no further information is available at this time. Diagnostic results and the increase in seizures suggest the possibility of a short circuit condition in the lead, but this cannot be confirmed.
 
https://www.accessdata.fda.gov/scripts/cdrh/cfdocs/cfmaude/detail.cfm?mdrfoi__id=1618755


Title: Re: Short Circuit
Post by: dennis100 on July 02, 2017, 01:27:39 AM
Model Number 302-20
Event Date 08/06/2010
Event Type Malfunction
Manufacturer Narrative
Device failure is suspected, but did not cause or contribute to a death or serious injury.

Event Description
It was reported that a vns patient experienced pain in the neck area due to unknown reason. Additional information was received from a company representative present at a follow-up appointment with the treating nurse and patient. The company representative indicated the patient had been complaining of intermittent pain in her neck for the past 2 weeks. The nurse and company representative performed system diagnostics with ok results and dcdc=2. The nurse indicated the patient' settings are 2. 0/20/250/30/5 and performed normal mode diagnostics with a dcdc=0. The neurologist said due to the pain and the dcdc=0, he believes there is a short circuit of the device and scheduled the patient for a full revision. The patient did some heavy lifting recently (oxygen tanks) and the neurologist believes that could have caused a problem. Additional information was received from the explanting site indicating the patient underwent generator and lead replacement surgery due to painful stimulation and lead problem. The patient was re-implanted and the explanted generator and lead were returned to the manufacturer to undergo product analysis.

https://www.accessdata.fda.gov/scripts/cdrh/cfdocs/cfmaude/detail.cfm?mdrfoi__id=1845862


Title: Re: Short Circuit
Post by: dennis100 on July 06, 2017, 08:17:09 AM
Model Number 300-20
Event Date 11/01/2010
Event Type Malfunction
Event Description
It was initially reported that vns patient was having increase in seizure activity. Follow up with the neurologist revealed that the seizure increase was at pre-vns baseline. However, after receiving patient's programming history, it was revealed that the device dcdc=0, indicating possible short circuit based on the patient's clinical symptoms. The patient suffers from mental retardation and it is unknown if he can perceive the normal/magnet stimulation. The magnet is still on and surgery has been planned with possible lead replacement because of the dcdc of 0.

Manufacturer Narrative
Device failure is suspected, but did not cause or contribute to a death or serious injury.

https://www.accessdata.fda.gov/scripts/cdrh/cfdocs/cfmaude/detail.cfm?mdrfoi__id=1963858


Title: Re: Short Circuit
Post by: dennis100 on July 08, 2017, 03:51:04 AM
Model Number 302-20
Device Problem Low impedance
Event Date 08/26/2005
Event Type  Malfunction   
Manufacturer Narrative

Event Description
It was reported that the vns device never worked for the patient. It was stated that it didn¿t work since after swiping the magnet they stated it did not help or lessen the seizure. The battery was reported to be depleted. A review of the manufacturer¿s in-house programming history database revealed there is evidence of fluctuating lead impedance levels, indicating a short circuit or low impedance condition. An estimate of battery life calculation was performed with the available history which indicated the battery to be depleted.

https://www.accessdata.fda.gov/scripts/cdrh/cfdocs/cfmaude/detail.cfm?mdrfoi__id=6645915


Title: Re: Short Circuit
Post by: dennis100 on July 28, 2017, 07:11:00 AM
Model Number 302-20
Event Date 01/01/2010
Event Type  Malfunction   
Manufacturer Narrative
Device failure is suspected, but did not cause or contribute to a death or serious injury.
 
Event Description
It was mentioned in a pt's clinic notes on (b)(6) 2010 that the "vagal nerve stimulator had been terribly effective initially but has worn off to the point where [the pt] is not sure it is working anymore". Also, the pt expressed concern that the device may be malpositioned, but this claim was refuted as the physician examined the location and found it to be adequately placed. Diagnostics on the date of the report were within normal limits. A subsequent system diagnostic test on (b)(6) 2010, also found the device to be properly functioning. However, a review of the pt's past diagnostic history in light of the pt's most recent diagnostic results given in the clinicals found a dcdc code suggesting a potential short circuit condition since the pt's efficacy has reportedly "worn off". Good faith attempts to date for more info have been unsuccessful.

https://www.accessdata.fda.gov/scripts/cdrh/cfdocs/cfmaude/detail.cfm?mdrfoi__id=2050183


Title: Re: Short Circuit
Post by: dennis100 on August 02, 2017, 08:36:46 AM
Model Number 102
Event Date 05/25/2011
Event Type  Injury   
Event Description
It was reported by a neurologist that vns pt had increase in seizures and could not perceive stimulation. Diagnostics were within normal limits. Pt's seizure activity has not changed since the last office visit on (b)(6) 2011. Pt's mother said that the pt no longer coughed like she used to. Pt stopped feeling stimulation about 2 - 3 months ago, despite the increase in settings on (b)(6) 2011. The settings were further increased to 2ma on (b)(6) 2011 but pt still was not able to perceive stimulation. The treating neurologist stated that he saw a dcdc = 0 when he performed sys diagnostics and was concerned about a short circuit and pt not feeling stimulation. Thus, pt will likely be referred for surgery. X-rays were taken and reviewed by the mfr. Generator placement appeared normal. The lead connector pin appeared to be completely inserted into the generator connector block. The generator feed-through wires appeared to be intact. The electrodes appeared to be in proper alignment. No gross fracture or lead discontinuities could be visualized on the lead portion assessed, however, there was a suspicious area noted in the bend caudal to electrodes, but cannot be confirmed due to a lack of clear lateral view of the chest. There was a portion of the lead body behind the generator that was unable to be assessed. Additionally, the previously placed electrodes and a small portion of the lead body were still present. The location of this portion of the device was cephalad to the most recent lead body.
 
Event Description
Additional information received revealed that the patient has not achieved the same efficacy since this current generator was implanted in that since surgery in 2009, the patient has experienced a slow gradual increase in seizure frequency. There were no reports of trauma or manipulation and the patient is tentatively scheduled for revision surgery later this month.
 
Manufacturer Narrative
Mfr reviewed x-rays of implanted device. X-rays reviewed by the mfr, no gross lead discontinuities visualized. Device failure is suspected, but did not cause or contribute to a death or serious injury.
 
Event Description
Product analysis of the explanted lead and generator has been completed. During analysis of the lead, puncture and slice marks were found on the outer silicone tubing which provided a leakage path for what appeared to be remnants of dried body fluids found inside the outer silicone tubing. The condition of the returned lead portions is consistent with conditions that typically exist following an explant procedure. No obvious anomalies were noted. The resistance measurement taken during decontamination verified an electrical and mechanical contact between the generator and connector pin at one point in time. Continuity checks of the returned lead portions were performed, during the visual analysis, with no discontinuities identified. Based on the findings in the product analysis lab, there is no evidence to suggest an anomaly with the returned portions of the device which may have contributed to the stated complaints. Note that since the electrode array section was not returned for analysis, an evaluation and resulting commentary cannot be made on that portion of the lead. During analysis of the explanted generator, it was noted that the septum was not cored thus eliminating the possibility of a potential unintended electrical current path through the body fluids (addressing the allegations of pain and painful stimulation). The pulse generator performed according to functional specifications. There were no performance or any other type of adverse conditions found with the pulse generator.

https://www.accessdata.fda.gov/scripts/cdrh/cfdocs/cfmaude/detail.cfm?mdrfoi__id=2172670


Title: Re: Short Circuit
Post by: dennis100 on August 03, 2017, 01:20:23 AM
Model Number 302-20
Event Date 11/16/2010
Event Type  Malfunction   
Manufacturer Narrative
Device failure is suspected, but did not cause or contribute to a death or serious injury.
 
Event Description
Reporter indicated a vns patient had low impedance with vns diagnostics testing (<600 ohms). The vns was disabled. Further review of vns programming history noted low impedance has been occurring since at least (b)(6) 2010, when it was noted to be 410 ohms. A short circuit condition of the lead is suspected. No trauma has been reported, but the patient's parents did manipulate the vns lead in the neck as they felt it was protruding under the skin. It is not known if this contributed to the low impedance. No x-rays have been performed. The plan of care is to refer for a surgical consult and revision surgery may occur in the future. The patient is currently stable on medications and doing well.

https://www.accessdata.fda.gov/scripts/cdrh/cfdocs/cfmaude/detail.cfm?mdrfoi__id=2185413


Title: Re: Short Circuit
Post by: dennis100 on August 06, 2017, 01:21:57 AM
Model Number 103
Event Date 07/04/2011
Event Type  Malfunction   
Event Description
It was reported that the pt started feeling painful stimulation at generator site a few weeks prior. Pt's current setting are 2. 5/30/500/30/5 magnet 30/60/500. Diagnostics were performed and results were within normal limits, 2595 ohms, ifi: no. The green light showing battery consumption was showing half full and the physician does not think this is correct. Based on pt's current settings, the pt's device should last about 4 years and half green light means the battery has 25% to 50% remaining battery life which is not expected. X-rays of the pt's device were taken and reviewed by the mfr. No anomalies were seen on the x-rays. The physician ran diagnostics with pt's head turned different ways. When the head was turned to the right, the pt did not feel painful stimulation, but when the head was turned to the left, the pt felt the painful stimulation. Diagnostics in all positions were ok. The physician lowered the settings and the pain resolved. Attempts for further info have been unsuccessful to date.
 
Event Description
Further information reveals the patient has a consult for the painful stimulation issue and a decision will be made on how to proceed. Attempts for further information have been unsuccessful to date.
 
Event Description
Decoder spreadsheet analysis was performed for the patient's vns programming history. A review of patient programming data revealed that on (b)(6) 2011 the initial interrogation of the device resulted in a measured battery voltage of 2. 849v, indicating that a 25% battery status indicator was displayed to the user during this interrogation (e. G. 25% remaining is displayed at measured voltages of 2. 85v with demipulse generators). All subsequent communication operations resulted in a measured voltage of 2. 68v at the same programmed settings, based on charge accumulation this would have resulted in the expected 100% status indicator. Based on this data, it is possible that battery associated with this generator may have been an outlier in terms of the battery impedance that is experienced at the beginning of battery life. The manufacturer addressed this issue with demipulse generators by adding a 0. 5v offset to measured battery voltage during the first 7. 5% of battery consumption to mitigate the potential for artificially low voltage measurements during this period. The fact that the voltage measurement of 2. 894v was received at 9. 560% of consumption may indicate that battery impedance for this particular generator was longer than most (e. G. An outlier). Based on all subsequent programming data the device appears to be functioning as intended.
 
Manufacturer Narrative
Analysis of programming history. The battery associated with this generator may have been an outlier in terms of the battery impedance that is experienced at the beginning of battery life.
 
Event Description
Further manufacturer investigation revealed that the root cause of the observed battery voltage behavior has been determined to be the result of either an extended duration of the reduced conductivity (i. E. High battery impedance) experienced by cfx batteries during the beginning of life (bol) or a minute internal short that managed to "burn" itself out resulting in the observed voltage rebound following 10% of discharge (e. G. Consumption). No change to risk has occurred as a result of this investigation, which continues to be "low. " change request numbers (b)(4) were created as a result of this investigation. (b)(4) proposes that the duration of the 0. 5v offset, implemented by the firmware for model 103/104/105/106 generators be extended from 7. 5% to 15% of consumption within 11. X programming software in order to mitigate such events in the future. (b)(4) proposes that this issue be mitigated either through the firmware (as the device is still under development) or through the programming software as well.

https://www.accessdata.fda.gov/scripts/cdrh/cfdocs/cfmaude/detail.cfm?mdrfoi__id=2245770


Title: Re: Short Circuit
Post by: dennis100 on August 06, 2017, 06:12:25 AM
Event Date 07/01/2011
Event Type  Malfunction   
Manufacturer Narrative
Device failure is suspected, but did not cause or contribute to a death or serious injury.
 
Event Description
It was reported by a company representative that a nurse suspected a short circuit condition on a vns pt that had dcdc of 0 since 2006, but prior to that, dcdc was 2. Furthermore, it was thought the pt's seizures had worsened slightly since then, but the change in dcdc code was not associated with the possibility of therapy not being delivered. The pt had a new generator implanted and was seen in clinic due to unawareness of stimulation. X-rays were performed and examined by the hospital and company representative. No strain relief bend and no tie downs were visualized and possibly the anchor tether was not on the nerve. The x-rays were received by the manufacturer and evaluated. The generator was visualized in the left upper abdomen, with its front part facing the front side of the abdomen. The filter feed-through wires appeared to be intact. The lead connector pins appeared to be fully inserted into the generator connector block. The state of the lead wires at the connector pin could not be assessed due to high density areas in the x-rays. The negative electrode appeared to be placed in normal arrangement. The positive electrode appeared to be partially detached from the nerve. The lead could not be fully assessed because of high density areas in the x-rays that concealed portions of the lead. No acute angles or lead breaks were observed in the assessed portions of the lead. Review of programming history with the pt's last generator indicated that system diagnostics dc dc had always been at 0 while normal diagnostics was indicative of 2. Programming history was not available for the recently implanted generator. The pt was referred for lead revision surgery and possible generator replacement surgery due to lead compatibility. No trauma was reported to have contributed to the event. Furthermore, information from the area representative indicated that no interventions have been planned even through replacement is needed.

https://www.accessdata.fda.gov/scripts/cdrh/cfdocs/cfmaude/detail.cfm?mdrfoi__id=2241014


Title: Re: Short Circuit
Post by: dennis100 on August 08, 2017, 01:46:13 AM
Model Number MODEL 250
Event Date 07/13/2011
Event Type  Malfunction   
Event Description
On (b)(6) 2011, a vns treating physician's nurse reported that they believed they had a short in their serial adapter cable because the programming system worked when they held it a certain way but otherwise it did not. The serial adapter cable was returned for product analysis which was completed on (b)(6) 2011. No anomalies associated with the serial cable were noted during testing. The serial cable performed according to functional specifications and provided consistent successful communication sequences in the product analysis lab. The mfr's consultant reported that the physician's programming system worked fine with a new serial cable.

https://www.accessdata.fda.gov/scripts/cdrh/cfdocs/cfmaude/detail.cfm?mdrfoi__id=2219823


Title: Re: Short Circuit
Post by: dennis100 on August 15, 2017, 01:05:45 AM
Model Number 302-20
Event Date 02/05/2009
Event Type  Malfunction   
Manufacturer Narrative
Describe event or problem, corrected data:follow-up report #2 inadvertently indicated attempts for the return of the explanted generator are in progress; instead of attempts for the return of the explanted lead are in progress.
 
Event Description
Attempts for the return of the explanted lead have been unsuccessful to date.
 
Manufacturer Narrative
Analysis of programming history. Device failure suspected but did not cause or contribute to a death or serious injury.
 
Event Description
Additional information was received from the neurologist indicating that the patient has been experiencing a return of seizures for some time. The physician was not sure if any trauma or manipulation had occurred. Patient's seizure frequency is known to fluctuate which makes difficult to determine if any medication changes or other factors may be contributing to the increased seizures. An implant card was later received indicating that the lead has been replaced. The reasons for replacement were noted as "pre-op high impedance" and "insulation stripped off. " lead impedance was noted as "ok" following surgery. Attempts for the return of the explanted generator are in progress.
 
Event Description
Analysis of the returned lead has been completed. The majority of the lead was not returned. A suspected abraded opening was observed at the end of the returned portion of the lead. Slight pitting was observed on the negative lead pin. No discontinuities were observed.
 
Manufacturer Narrative
Only a portion of the lead was returned for analysis which did not reveal any anomalies. An abraded opening is suspected at the returned end however device failure is suspected in the lead portion not returned, but did not cause or contribute to a death or serious injury. (b)(4).
 
Event Description
Review of the pt's vns diagnostics history found that on (b)(6) 2009, systems diagnostics indicated the pt's impedance value was 586 ohms which is below the current low impedance threshold (i. E. 600 ohms) indicative of a short circuit condition of the lead. No adverse events have been reported. A review of programming history associated with the pt's previous generator revealed a dramatic drop in dcdc code between (b)(6) 2003 and (b)(6) 2005. Attempts to the pt's physician for further info on any effects on the pt's condition have been unsuccessful to date.
 
Event Description
The explanted lead has been received and is currently undergoing analysis.

https://www.accessdata.fda.gov/scripts/cdrh/cfdocs/cfmaude/detail.cfm?mdrfoi__id=2266022


Title: Re: Short Circuit
Post by: dennis100 on August 16, 2017, 04:07:47 AM
Model Number 300-20
Event Date 06/02/2009
Event Type  Malfunction   
Event Description
On (b)(6) 2011, the patient's programming history was reviewed and it was discovered that the patient has an impedance value of 558ohms on (b)(6) 2009. An impedance value less than 600 ohms indicates the potential presence of a short-circuit condition. (b)(4) attempts are underway by the manufacturer's consultant, but no further information has been received from the physician to date. When additional information is received, it will be reported.
 
Event Description
Additional information was received on (b)(6) 2013 when it was discovered that the patient underwent a full revision surgery on (b)(6) 2013. The lead impedance after surgery was noted to be "ok". The explanted products could not be returned to the manufacturer for product analysis as the hospital does not return them.
 
Event Description
Additional information was received on (b)(6), 2011 when the manufacturer's consultant reported that the physician is going to have the patient come back in for a clinical visit to run diagnostics since the last time the patient was seen was sometime in 2009. The patient was seen on (b)(6), 2011 and the physician saw a low impedance warning message upon interrogation. The manufacturer's consultant reported that the normal mode diagnostics test showed an impedance value of 602ohms and a systems diagnostic test showed low impedance. The programming history was sent to the manufacturer for review. The manufacturer's consultant reported that the patient is doing well and not having any adverse events; therefore no surgery will occur right now.
 
Event Description
On (b)(4) 2011, additional information was received when the manufacturer's consultant reported that she is trying to get the patient to see the physician in order to have diagnostics performed. The physician was not there last time the patient and manufacturer's consultant visited him to have diagnostics performed. The physician was not aware of any low impedance or clinical symptoms resulting from the low impedance. When additional information is received, it will be reported.
 
Event Description
On (b)(4) 2012 clinic notes were received dated (b)(6) 2011. Review of the notes revealed that the patient had borderline low impedance value of 558ohms. The patient's vns had not been checked since 2009. The patient's settings were noted to be output=1. 5ma/frequency=20hz/pulse width=250usec/on time=7sec/off time=0. 2min/magnet output=1. 75ma/magnet on time=60sec/magnet pulse width=250usec. System diagnostics showed the lead impedance to be 602ohms which was within normal limits although borderline low and the output status was "ok. " the lead impedance was checked again and it was found to be 600ohms. It was decided that this would be watched carefully. The physician checked the battery position and the leads and did not see any evidence of any abnormalities. The magnet test was also performed and was normal with an impedance value of 602ohms. Tympanic membranes showed some scarring but no acute anomalies. The patient's mother noted some possible drainage from the right ear but the physician did not see anything acute. The physician later reported on (b)(6) 2012 that the patient was shown to have "lead impedance as well as nearing end of service on his generator. " the patient was referred for surgery. Clinic notes from the (b)(6) 2012 visit were also received which indicated that the lead impedance was gain borderline low, around 600ohms. The patient's on time was decreased to 0. 3sec and the patient's lead impedance was re-checked with it still showing borderline low. The patient is having 3+ seizures a day according the patient's mother; they have not really changed in character over the last year. Although surgery is likely, it has not occurred to date.
 
Manufacturer Narrative
Device failure is suspected, but did not cause or contribute to a death or serious injury.

https://www.accessdata.fda.gov/scripts/cdrh/cfdocs/cfmaude/detail.cfm?mdrfoi__id=2232395


Title: Re: Short Circuit
Post by: dennis100 on August 23, 2017, 02:24:25 AM
Model Number MODEL 250
Event Date 10/18/2011
Event Type  Malfunction   
Event Description
The suspect flashcard was sent to the flashcard manufacturer, and an analysis of the flashcard identified that the cause of the flashcard anomaly is associated with a bad (shorted) capacitor. Once the capacitor was replaced with a known good capacitor, no further anomalies were identified. Additionally since the short was a power to ground failure, the current drain from the flashcard would cause the handheld to lockup when the flashcard was inserted.
 
Event Description
The vns computer and flashcard were returned for analysis. An analysis was performed on the returned computer. No anomalies associated with the handheld performance were noted during testing using the ac adapter or the main battery with a full charge. The handheld performed according to functional specifications. During the flashcard analysis it was identified that the flashcard was unresponsive and causing the computer to lock-up when it was inserted. The flashcard was sent to the flashcard manufacturer to determine an exact root cause for the anomaly. Once it is determined, an amendment will be added to the analysis identifying the root cause and the results will be reported.
 
Event Description
Reporter indicated a dell x50 vns computer screen was not responding to the stylus. The screen lock button was off. A hard reset resolved the issue, but the reporter was not able to advance past the "align screen" prompt. Attempts for product return are in progress.
 
Manufacturer Narrative
Device evaluated by flashcard manufacturer.
 
Manufacturer Narrative
Device failure is suspected, but did not cause or contribute to a death or serious injury.

https://www.accessdata.fda.gov/scripts/cdrh/cfdocs/cfmaude/detail.cfm?mdrfoi__id=2337348



Title: Re: Short Circuit
Post by: dennis100 on August 29, 2017, 01:08:04 AM
Model Number MODEL 250
Event Date 11/29/2011
Event Type  Malfunction   
Event Description
It was initially reported that the physician's handheld was not functioning properly and there was a suspected "short" in the serial adaptor cable. No further information was provided. (b)(4) attempts for more information and product return have been unsuccessful to date.
 
Manufacturer Narrative

Event Description
Additional information was received that the handheld was lost by the physician and will not be returned to the manufacturer for evaluation.

https://www.accessdata.fda.gov/scripts/cdrh/cfdocs/cfmaude/detail.cfm?mdrfoi__id=2383808


Title: Re: Short Circuit
Post by: dennis100 on September 07, 2017, 03:21:29 AM
Model Number 302-20
Event Date 08/21/2009
Event Type  Malfunction   
Event Description
Reporter indicated the current high lead impedance is dcdc = 4 with systems testing and dcdc = 6 for normal mode testing. The patient's increased seizures may be due to the high lead impedance per the reporter. The patient's "regular" seizures are increased, but the relationship to pre-vns baseline is unknown. The patient was seizure free for 18 months after initial vns implant, and is now having one seizure a week. The vns has not been disabled. The patient has had no known trauma. Vns revision surgery is planned for (b)(6) 2012.
 
Manufacturer Narrative
Type of report, corrected data: the initial mdr report inadvertently omitted the 30-day report designation.
 
Event Description
Reporter indicated the patient had vns lead and generator replacement surgery performed on (b)(6) 2012. The explanted lead and generator were discarded by the hospital after the surgery.
 
Manufacturer Narrative
Manufacturer reviewed x-rays of implanted device. X-rays reviewed by the manufacturer, no gross lead discontinuities visualized. Device failure is suspected.
 
Event Description
Reporter indicated a vns patient had high lead impedance with diagnostics testing and was also having increased seizures. The patient has had high lead impedance with dcdc = 4 for vns systems testing since at least (b)(6) 2009. At that time, no adverse patient events were occurring and no interventions were planned. X-rays previously reviewed on (b)(6) 2010, did not reveal any lead anomalies. Vns generator and lead replacement surgery appears likely, but has not occurred to date. Attempts for further information are in progress.
 
Event Description
An implant card was received back to the manufacturer documenting the vns lead and generator replacement surgery on (b)(6) 2012. Vns diagnostics prior to the explant indicated a dcdc = 0. As the dcdc code had previously been 4, it is suspected the high lead impedance had progressed to a short circuit (low impedance) condition of the lead. The diagnostics with the new vns lead and generator were 909 and 849 ohms, which is within the normal range.

https://www.accessdata.fda.gov/scripts/cdrh/cfdocs/cfmaude/detail.cfm?mdrfoi__id=2503832



Title: Re: Short Circuit
Post by: dennis100 on September 08, 2017, 10:53:30 AM
Device Problem Low impedance
Event Date 07/13/2017
Event Type  Malfunction   
Manufacturer Narrative

Event Description
It was reported by a medical professional that a vns patient was experiencing discomfort over the medial side of the generator, and on palpation describes some tenderness when palpating that area. She reported that when she checked the device the diagnostics she was concerned of a short circuit condition. The patient was noted to have had 2 seizures that have been more severe over the past 2 months. A chest x-ray was taken and nothing abnormal was reported by the clinician. The x-rays have not been received by the manufacturer for review to-date. Additional relevant information has not been received to-date.

https://www.accessdata.fda.gov/scripts/cdrh/cfdocs/cfmaude/detail.cfm?mdrfoi__id=6772168


Title: Re: Short Circuit
Post by: dennis100 on September 12, 2017, 07:12:54 AM
Model Number 302-20
Event Date 03/02/2012
Event Type  Malfunction   
Manufacturer Narrative
Device malfunction suspected, but did not cause or contribute to a death or serious injury.
 
Event Description
A country manager in sweden was notified by a vns surgeon that a patient had their generator explanted for a suspected infection. Their generator was explanted on (b)(6) 2012 and their lead has been left in place as possibly a new generator may be placed later. The patient's surgery was a scheduled planned replacement, no clinical signs of infection, when opening the pouch there was a yellow fluid, possibly from blood and it was noted the generator appeared corroded. Cultures were taken and no infection was confirmed. Since no infection was present, there is likely a correlation between the corrosion and the presence of the stained fluid. There was no patient manipulation or trauma prior to the event. The fluid was noted around the generator, subclavical area. During review of internal programming history it was noted that the patient had high lead impedance on (b)(6) 2008 and later on (b)(6) 2010, a dcdc 0 on their system diagnostic test indicating a possible short circuit condition. At this time the lead remains implanted in the patient.
 
Event Description
On (b)(6) 2013 the programming history for the patient's currently implanted generator was reviewed and high impedance was observed on (b)(6) 2012. The same lead was previously implanted with the patient's previous generator and high impedance was detected. On (b)(6) 2012 patient underwent surgery for generator replacement and the lead was left in place. Good faith attempts for further information were made but no additional information was received.
 
Manufacturer Narrative
Analysis of programming history.
 
Event Description
Additional information was received on (b)(6), 2012 when it was discovered that the patient had undergone re-implant surgery on (b)(6), 2012. The vns device had been explanted 6 months prior due to suspected infection.
 
Event Description
Additionally, analysis was completed on the returned generator. Analysis of the returned generator indicated the generator was not corroded. In addition, dried bodily fluid remnants were observed in the header lead cavity, both connector blocks, and the feed-thru area. There were signs of fluid ingress/egress (direction of fluid flow could not be determined) through both of the negative and positive connector blocks backfill areas. Pitting (etching/corrosion) was observed on the negative connector block and setscrew. Nonetheless, the findings of fluid inside the generator possibly contributed to the low dc dc and also high impedance.
 
Event Description
An implant card was received stating that the vns patient underwent generator and lead replacement surgery on (b)(6) 2014 because the device was dysfunctional. Attempts for additional relevant information were made but have been unsuccessful to date.
 
Event Description
Additional information was received through a return product form indicating the reason for explant was due to localized 'empyema' as well as corroded stimulator. At the moment good faith attempts to obtain further information from the treating physician have been unsuccessful to date.

https://www.accessdata.fda.gov/scripts/cdrh/cfdocs/cfmaude/detail.cfm?mdrfoi__id=2525223


Title: Re: Short Circuit
Post by: dennis100 on September 14, 2017, 12:37:35 AM
Model Number 302-20
Event Date 07/29/2011
Event Type  Malfunction   
Manufacturer Narrative
Date of event, corrected data: the correct event date for the high lead impedance is provided. Device failure occurred, but did not cause or contribute to a death or serious injury.
 
Event Description
Reporter indicated the painful stimulation was felt to be related to a "short-circuit" of the vns. X-rays were taken but were not forwarded to the manufacturer. The high lead impedance was first noted on (b)(6) 2011, and the patient had reported feeling electrical shock sensations in her neck when turning her head to the left for the previous month. Vns diagnostics were last within normal limits in (b)(6) 2010. Analysis of the explanted vns generator and lead was completed. No anomalies were identified with the vns generator and the generator performed per specifications. During the lead visual analysis of the returned 35mm lead portion, the green (-) electrode quadfilar coil appeared to be broken approximately 12mm from the distal end of the anchor tether. Scanning electron microscopy was performed and identified the area as being mechanically damaged and pitted which prevented identification of the coil fracture type. It is believed that stimulation was present for a certain period of time as evidenced by the presence of metal pitting. Low magnification sem analysis of the quadfilar coil shows characteristics typical of a lead discontinuity which may include: material fracture, rough or pitted surface, thinned material thickness, electro-etching or material dissolution. With the exception of the observed discontinuity, the condition of the returned lead portions is consistent with conditions that typically exist following an explant procedure. The setscrew marks found on the lead connector pin provide evidence that, at one point in time, a good mechanical and electrical connection was present. Continuity checks of the returned lead portions were performed, during the visual analysis, and no other discontinuities were identified.
 
Manufacturer Narrative
Device failure is suspected.
 
Event Description
Reporter indicated a patient was noted to have high lead impedance with vns diagnostics in (b)(6) 2011. The patient was also experiencing painful vns stimulation in her shoulder. The vns was disabled, but no other interventions were done as the patient was pregnant at the time. The patient does have a history of falling with her seizures. The patient delivered her baby in (b)(6) 2012 and surgical replacement of the vns lead and generator occurred on (b)(6) 2012. Diagnostics with the new generator and resident lead still indicated high lead impedance, ruling out a lead pin issue and making a lead fracture more likely. Diagnostics with the new lead and new generator were within normal limits. However, during explant of the resident lead, the jugular vein was nicked which required a vascular surgeon to assist with the repair. The new vns system was left disabled. The explanted generator and lead have been returned and are pending analysis. Attempts for further information are in progress.

https://www.accessdata.fda.gov/scripts/cdrh/cfdocs/cfmaude/detail.cfm?mdrfoi__id=2513252


Title: Re: Short Circuit
Post by: dennis100 on September 19, 2017, 02:55:35 AM
Model Number 102
Event Date 01/01/2010
Event Type  Malfunction   
Event Description
It was reported that a vns patient had their device explanted for lack of efficacy and neck pain. Additionally reported that it was malfunctioning. The patient was not re-implanted. It was reported that the patient had been turned off for sometime and they just decided to take out the generator because it wasn't working. Their explanted generator is at the manufacturer pending completion of product analysis. Their explanted lead was returned. An analysis was performed on the returned lead portion the condition of the returned lead portion is consistent with conditions that typically exist following an explant procedure. No obvious anomalies were noted. The resistance measurement taken during decontamination verified an electrical and mechanical contact between the generator and connector pin at one point in time. Continuity checks of the returned lead portion were performed, during the visual analysis, with no discontinuities identified. Based on the findings in the product analysis lab, there is no evidence to suggest an anomaly with the returned portion of the device which may have contributed to the stated complaint. Note that since the lead assembly (body) including the electrode array section was not returned for analysis, an evaluation and resulting commentary cannot be made on that portion of the lead.
 
Manufacturer Narrative

Event Description
Additional information was obtained that their treating physician felt the patient's pain was related to the presence of their implanted device. No programming changes occurred prior to the reported event. No patient fall or injury. There was no device malfunction the patient was a non responder to their vns therapy. Their device was removed for patient comfort. Due to the as-received condition of the pulse generator, proper functionality of the pulse generator in its ability to provide appropriate programmed output currents cannot be verified. However, the septum was not cored, thus eliminating the possibility of a potential unintended electrical current path through body fluid. Due to the puncture possibly sustained from the explant process, fluids from the explant and decontamination process inadvertently penetrated to the interior of the pulse generator resulting in an electrical short rendering the generator substrate un-repairable for further testing (adhesive was applied prior to decontamination to prevent ingress of fluid, but was unsuccessful). The damage sustained by this device appears to have occurred during the explant procedure, based on the physical indentations that were observed on the generator case exterior. All information indicates the generator performed as intended prior to sustaining the explant-related damage.
 
Manufacturer Narrative
Adverse event or problem. Corrected data: malfunction removed. Electrical testing could not be performed as fluid was inside the generator can. No device malfunction suspected prior to explant. No patient death from event.

https://www.accessdata.fda.gov/scripts/cdrh/cfdocs/cfmaude/detail.cfm?mdrfoi__id=2669183


Title: Re: Short Circuit
Post by: dennis100 on September 21, 2017, 12:29:09 AM
Model Number MODEL 250
Event Date 07/01/2007
Event Type  Malfunction   
Manufacturer Narrative
Device failure is suspected, but did not cause or contribute to a death or serious injury.
 
Event Description
It was reported that a site's handheld ac adapter shorted out when it was plugged into an electrical outlet. A replacement ac adapter was sent. Attempts to have original ac adapter returned have been unsuccessful.

https://www.accessdata.fda.gov/scripts/cdrh/cfdocs/cfmaude/detail.cfm?mdrfoi__id=897927


Title: Re: Short Circuit
Post by: dennis100 on October 24, 2017, 12:27:35 AM
Event Date 10/01/2013
Event Type Malfunction
Manufacturer Narrative

Event Description
On (b)(6) 2013, it was reported that a vns patient was experiencing an increase in seizures. The physician stated that the impedance three months prior was 1200 ohms. The impedance in (b)(6) 2013 was 800 ohms. The physician wondered if the event may be related to a short-circuit condition. Attempts for additional information have been unsuccessful.

https://www.accessdata.fda.gov/scripts/cdrh/cfdocs/cfmaude/detail.cfm?mdrfoi__id=3452760


Title: Re: Short Circuit
Post by: dennis100 on December 03, 2017, 03:16:47 AM
Model Number MODEL 250
Device Problems No display or display failure; Device operates differently than expected
Event Date 09/18/2015
Event Type Malfunction
Event Description
Analysis of the returned handheld computer was completed and no anomalies associated with the display were identified during the analysis. During the analysis, it was identified that the handheld would power down when the serial cable was inserted. The cause for the anomaly is associated with bent pins in the serial hood assembly that created an electrical short and caused the handheld to power down. Full handheld computer functionality was restored after replacement with a known good cable. No other anomalies were identified. Analysis of the software was completed and no anomalies associated with the flashcard software or databases were identified during the flashcard analysis. The flashcard and software performed according to functional specifications.

Event Description
The suspected handheld computer was returned to the manufacturer on 10/21/2015. Analysis is underway but it has not been completed to date.

Event Description
It was reported that the medical professionals were having difficulties to use their programming system. It was reported that the handheld computer screen does not light up anymore. The physicians were having problems to adjust the handheld settings.

https://www.accessdata.fda.gov/scripts/cdrh/cfdocs/cfmaude/detail.cfm?mdrfoi__id=5146710


Title: Re: Short Circuit
Post by: dennis100 on January 06, 2018, 02:58:12 AM
Model Number 304-20
Device Problem Low impedance
Event Date 12/08/2017
Event Type Malfunction
Manufacturer Narrative

Event Description
It was reported that a low impedance warning message was observed when the patient¿s device was interrogated during a routine office visit. A low impedance warning typically indicates that a short circuit condition may be occurring. The physician ordered x-rays and was considering referring the patient for a lead revision. No additional relevant information has been received to date. No surgical interventions are known to have occurred to date.

https://www.accessdata.fda.gov/scripts/cdrh/cfdocs/cfmaude/detail.cfm?mdrfoi__id=7134423


Title: Re: Short Circuit
Post by: dennis100 on January 07, 2018, 03:40:12 AM
Model Number 300-20
Device Problems Mechanical issue; Low impedance
Event Date 01/18/2017
Event Type Malfunction
Event Description
It was reported that the patient had not been feeling vns stimulation since a recent generator replacement. Diagnostics were performed at an office visit which resulted in a low impedance warning. The patient confirmed that he did not fall or hit the generator since the surgery. X-rays were performed and reviewed by the physician who stated that the lead pin was fully inserted. These x-rays have not been reviewed by the manufacturer to date. The generator was not programmed off after the low impedance warning was observed. It was later reported that the patient was experiencing an increase in seizures since the low impedance had been observed. The patient was then referred for replacement surgery. It was unclear if the surgery would just be a lead replacement or a lead and generator replacement. No surgical interventions are known to have occurred to date.

Event Description
The patient underwent a lead and generator replacement due to the low impedance. The explanted lead and generator were received by the manufacturer and they are both currently pending analysis. Further follow-up with the physician clarified that the increase in seizures was below pre-vns baseline.

Event Description
Product analysis on the generator found that the device performed to functional specification. Magnet activations were successfully performed and the device provided the programmed settings. Analysis on the lead found that there was abraded insulation in the inner tubing which potentially allowed for a short circuit condition to occur.

https://www.accessdata.fda.gov/scripts/cdrh/cfdocs/cfMAUDE/detail.cfm?mdrfoi__id=6339315


Title: Re: Short Circuit
Post by: dennis100 on January 12, 2018, 01:47:38 AM
Model Number 302-30
Event Date 04/04/2006
Event Type Malfunction
Manufacturer Narrative
Manufacturer reviewed x-rays of implanted device. X-rays reviewed by manufacturer, no gross lead discontinuities visualized.

Event Description
Reporter indicated a vns patient had systems diagnostics results with dcdc = 0 and was concerned this may indicate a short circuit condition in the vns lead. The dcdc = 0 was first noted on (b) (6) 2006 and is still occurring as of (b) (6) 2009. The patient is non-verbal and cannot report if vns stimulation is felt. The patient has had decreasing efficacy over the last 6 months and increased seizures that are not greater than pre-vns baseline levels. X-rays were reviewed. The electrodes appeared in alignment but also appeared stretched. A sharp angle was noted in a suspicious area of the lead boy just superior to the generator header. No obvious lead discontinuities were noted. All attempts for further information from the reporter have been unsuccessful to date.

https://www.accessdata.fda.gov/scripts/cdrh/cfdocs/cfmaude/detail.cfm?mdrfoi__id=1496318


Title: Re: Short Circuit
Post by: dennis100 on January 16, 2018, 05:07:17 AM
Event Date 01/08/2010
Event Type Malfunction
Manufacturer Narrative
Device failure is suspected, but did not cause or contribute to a death or serious injury.

Event Description
Reporter indicated vns low impedance readings, followed by high lead impedances, and then low impedance were obtained at an office visit. The pt had generator replacement earlier in the day. The reporter was advised to disable the vns. Programming history was obtained via flashcard download which revealed the high impedance message was due to the pt's generator being programmed on before any diagnostics were performed. The stored impedance value in the generator occurs during manufacturing and is cleared by performing a systems diagnostics test. Review of the pt's previous generator programming history identified dcdc codes of 0. The current low impedance values and the history of dcdc = 0 with the previous generator is indicative of a suspected lead problem, such as a short circuit or fracture. Further attempts for info are in progress.

https://www.accessdata.fda.gov/scripts/cdrh/cfdocs/cfmaude/detail.cfm?mdrfoi__id=1616312


Title: Re: Short Circuit
Post by: dennis100 on February 06, 2018, 02:09:51 AM
Model Number 300-20
Event Date 01/01/2011
Event Type Malfunction
Event Description
It was reported by a physician that the patient was referred for explant due to painful stimulation in the neck region, which occurred every 3 minutes. The patient's current settings were 2. 5 ma/20 hz/250 microsec/30 sec/3 min. System diagnostic were within normal limits, but with a dcdc code of 0. The patient's past programming history was reviewed and it was noted that the dcdc code had been 1 or 2 previously; therefore, the patient was scheduled for a revision due to a potential short circuit. There was no report of manipulation or trauma. X-rays were not going to be taken. The patient underwent a full revision - the generator was returned for product analysis, but the lead was not returned.

Manufacturer Narrative
Device failure is suspected, but did not cause or contribute to a death or serious injury.

https://www.accessdata.fda.gov/scripts/cdrh/cfdocs/cfmaude/detail.cfm?mdrfoi__id=2094902


Title: Re: Short Circuit
Post by: dennis100 on March 05, 2018, 02:10:11 AM
Model Number 104
Event Date 04/19/2012
Event Type Malfunction
Manufacturer Narrative
Analysis of programming history performed.

Manufacturer Narrative
Type of report, corrected data: inadvertently did not list as 30-day report on initial report.

Event Description
On (b)(6) 2012, a vns treating nurse practitioner reported that when the vns patient was seen for a clinical visit on (b)(6) 2012, it was noted that his settings were output=0ma/frequency=30hz/pulse width=500usec/on time=30sec/off time=5min/magnet output=0ma/magnet pulse width=500usec/magnet on time=60sec. The nurse stated that he doesn't think the patient was intentionally programmed off on his last visit, but he was unable to confirm as the handheld and flashcard were returned to the manufacturer for product analysis for an unrelated issue (report on manufacturer report number 1644487-2012-01253). The patient did admit to using a weight loss stimulation belt recently. Diagnostics were performed on (b)(6) 2012 and results showed the device to be functioning properly with an impedance value of 2586 ohms and not at end of service. The nurse stated that the patient was supposed to have been at output=2ma/frequency=30hz/pulse width=500usec/on time=30sec/off time=5min. The patient was reprogrammed to output=1. 75ma/frequency=30hz/pulse width=500usec/on time=30sec/off time=5min on (b)(6) 2012, without any problems. As previously reported on manufacturer report number 1644487-2012-01253, product analysis on the flashcard revealed no anomalies associated with flashcard software or databases; the flashcard and software performed according to functional specifications. Product analysis of the handheld confirmed that the device would not power on or off. The cause for this condition was an open fuse in the handheld associated with a defective serial cable that had an electrical short; vendor issue. Following replacement with known good fuse, full product functionality was restored. No further anomalies associated with the handheld were noted during testing using the ac adapter or the main battery with a full charge.

Manufacturer Narrative
Analysis of programming history.

Manufacturer Narrative
Corrected data: initial report inadvertently listed wrong product.

Event Description
Programming history was received and reviewed and it was found that the reason the device was found to be programmed off on (b)(6) 2012 was because the device was not programmed on until it was found to be off on (b)(6) 2012.

Event Description
On (b)(6) 2012, the programming history from the handheld and flashcard that the nurse had stated contained the patient's programming history was reviewed and it did not contain any programming history for the patient.

https://www.accessdata.fda.gov/scripts/cdrh/cfdocs/cfmaude/detail.cfm?mdrfoi__id=2582110


Title: Re: Short Circuit
Post by: dennis100 on March 08, 2018, 01:23:34 AM
Model Number 302-20
Event Date 01/16/2009
Event Type Malfunction
Event Description
Reporter indicated a patient was having increased generalized seizures in (b)(6) 2012, and that the vns generator battery was "failing". A generator battery life estimate performed by the manufacturer yielded -0. 69 years remaining, indicating battery end of service is likely. The increase in seizures was felt to be due to the generator "failing". The patient has been referred for generator replacement. Manufacturer review of the patient's vns programming history noted the diagnostics dcdc code for systems testing has been 0 since at least (b)(6) 2009. Prior to that date, the dcdc code was 1 as of (b)(6) 2008, and as of (b)(6) 2007 the dcdc code was 2. The dcdc code was also 2 on (b)(6) 2004, which was 4 months after initial implant on (b)(6) 2004. As the dcdc code has dropped from 2 to 0 and the patient is experiencing increased seizures, a short circuit of the lead may be occurring. Attempts for further information are in progress.

Event Description
Reporter indicated the patient had vns generator replacement performed on (b)(6) 2012. Attempts for additional information and return of the explanted generator are in progress.

Event Description
Reporter indicated the patient feels magnet mode stimulation, and there was no mention of multiple seizure types increasing. No other information was provided. Vns replacement surgery is still planned, but has not occurred to date.

Event Description
Additional follow-up with the explanting hospital revealed the vns generator was discarded after the surgery.

Event Description
Reporter indicated device diagnostics with the new vns generator and resident lead were within normal limits at the surgery on (b)(6) 2012. All attempts for return of the explanted vns generator have been unsuccessful to date.

Manufacturer Narrative
Device failure is suspected.

https://www.accessdata.fda.gov/scripts/cdrh/cfdocs/cfmaude/detail.cfm?mdrfoi__id=2620658


Title: Re: Short Circuit
Post by: dennis100 on March 12, 2018, 01:24:32 AM
Model Number 302-20
Event Date 12/26/2006
Event Type Malfunction
Event Description
Manufacturer review of a patient's vns programming history noted the diagnostics dcdc codes were all "0" in the history, except for one date ((b)(6) 2006) when it was dcdc = 2. Dcdc = 0 may indicate a short circuit condition in the lead. The patient has also been having breakthrough seizures since (b)(6) 2011 as reported by the surgeon via clinic notes received to the manufacturer. As the dcdc value has been "0" consistently since (b)(6) 2006 (was dcdc = 2 on (b)(6) 2006) and the patient is having adverse events (breakthrough seizures), a short circuit condition of the lead is suspected. Attempts for further information are in progress.

Manufacturer Narrative
Device failure occurred.

Manufacturer Narrative
Device failure is suspected.

Event Description
The patient had vns lead and generator replacement surgery on (b)(6) 2012, which was previously reported via mdr #1644487-2012-02031. During the surgery, the surgeon noted the lead was fractured and that low impedance <600 ohms was observed. No x-rays were done prior to the surgery, and it was unknown if the patient had any trauma. Vns diagnostics with the new devices were within normal limits. The explanted devices were returned for analysis on (b)(6) 2012, which was previously reported on mdr #1644487-2012-02031. No anomalies were noted with the generator. Surface wear on adjacent areas of both positive and negative coils were noted on the lead portion. A break was identified on both positive and negative lead coils. Scanning electron microscopy images of the positive coil showed what appears to be wear (flat surfaces) on the coil strands resulting in reduction of the diameter of the quadfilar coil strands. The strands appear to be torn at the worn areas. Also, the early stages of a secondary fracture were identified in one strand of the quadfilar coil in the vicinity of the worn surfaces suggesting that the positive coil was torn during the explant procedure. Scanning electron microscopy images of the negative coil showed what appears to be wear (flat surfaces) on the coil strands resulting in reduction of the diameter of the quadfilar coil strands, up to the point of a break. Note that since a portion of the lead (including the electrode array) was not returned for analysis, an evaluation and resulting commentary cannot be made on that portion of the lead. Other than the above mentioned conditions and typical wear & explant related observations, no other anomalies were identified in the returned lead portion. Analysis confirmed a discontinuity of negative quadfilar coil in the electrode region of the returned lead portions; also observed abraded inner tubing openings and wear on adjacent areas of both coils, suggesting a possible short-circuit condition. The increased seizures were felt to be due to no therapy being delivered from the low impedance/short circuit/fracture. The patient is improving since the surgery, and is being slowly titrated up with the new devices.

https://www.accessdata.fda.gov/scripts/cdrh/cfdocs/cfmaude/detail.cfm?mdrfoi__id=2655277


Title: Re: Short Circuit
Post by: dennis100 on March 25, 2018, 01:31:39 AM
Model Number 302-20
Event Date 10/22/2012
Event Type Malfunction
Event Description
Reporter indicated a vns patient had low lead impedance 60:000 ohms with device diagnostics. The patient is having no adverse events at this time, and is seizure-free. The patient had no trauma and does not manipulate the vns. The reporter declined to disable the vns, as the patient is doing well clinically with her seizures. The reporter was made aware of the manufacturer's recommendation to disable the vns due to the low impedance. X-rays were reviewed by the manufacturer and no obvious lead anomalies were noted. There was a slight twist to the lead body in approximately the first 1/3 of the available lead body view, but this may not be a significant finding. The lead pin was fully inserted. The filter feedthrus were intact. There was some lead behind the generator that cannot be assessed. The lead was intact at the lead pin. The cause of the low lead impedance is not apparent in the x-rays, but may be due to a possible short in the lead body under the generator or in a different area of the lead. The plan of care is to continue to observe the patient clinically with the vns enabled.

Manufacturer Narrative
Manufacturer reviewed x-rays of implanted device x-rays reviewed by the manufacturer, no gross lead discontinuities visualized. Device failure is suspected, but did not cause or contribute to a death or serious injury.

https://www.accessdata.fda.gov/scripts/cdrh/cfdocs/cfmaude/detail.cfm?mdrfoi__id=2833992


Title: Re: Short Circuit
Post by: dennis100 on March 28, 2018, 01:43:10 AM
Model Number 302-20
Event Date 11/14/2012
Event Type Malfunction
Manufacturer Narrative
Manufacturer reviewed x-rays of implanted device. Analysis of programming history. X-rays reviewed by the manufacturer, no gross lead discontinuities visualized. Device failure is suspected by physician, but did not cause or contribute to a death or serious injury.

Event Description
It was initially reported that the patient had a dcdc code of 0 on both systems and normal mode. The patient also reported that he had not been feeling stimulation. It was suggested that the output current could be increased to see if the patient felt stimulation but the patient was already at 3. 5 ma and increasing the output current would not be an option. The patient was sent for x-rays and the x-rays were provided to the manufacturer for review. Based on the x-rays received, no obvious anomalies were identified that could be contributing to a short circuit. There were no gross fractures or discontinuities that were visualized. As the entire lead could not be assessed, continuity in that portion of the lead cannot be confirmed and the possibility of a micro-fracture cannot be ruled out. Review of the patient diagnostics in the manufacturers programming history showed that the patient has always had dcdc code of 0 on system diagnostics. The physician's office was concerned that there may be a lead break so the patient was referred for a lead and generator replacement. Surgery is likely but has not occurred to date. There was no reported trauma or manipulation. The dcdc code of 0 is the reason that the office felt there may be a lead break. They understand based on the patients history that dcdc code of 0 may not be a lead break but they wanted to replace the patient just to be sure.

Event Description
Additional information was received that the patient had a generator and lead replacement. Prior to surgery diagnostics run. The generator was replaced first and diagnostics were run with the new generator both outside and inside the pocket. When diagnostics were run inside the pocket low impedance was received. It was decided to replace the lead. When diagnostics were run again they were within normal limits. The generator and lead were returned to the manufacturer for evaluation. Product analysis is planed but has not been completed.

Manufacturer Narrative
Only a portion of the lead was returned for analysis which did not reveal any anomalies. Device failure is suspected in the lead portion not returned, but did not cause or contribute to a death or serious injury.

Event Description
Additional information was received that product analysis was completed on the generator and lead. The generator output signal was monitored for more than 24 hours while the generator was placed in a simulated body temperature environment, with results showing no signs of variation in the pulse generator's output signal and demonstrated that the device provided the expected level of output current for the entire monitoring period. Visual examination noted tool marks on the pulse generator case, most likely associated with manipulation of the device during the explant procedure as the markings are consistent with devices typically used in a surgical procedure (forceps, etc. ) the pulse generator diagnostics were as expected for the programmed parameters. The generator performed according to functional specifications. During the product analysis there were no anomalies found with the pulse generator. A small portion of the lead assembly (body) including the electrodes was not returned for analysis; therefore, a complete evaluation could not be performed on the entire lead product. Additionally one loose tie down was returned. During the visual analysis pitting was observed on the surface of the connector pin. Sem was performed and identified evidence of being melted and pitting on the surface of the connector pin. Energy dispersion spectroscopy (eds) was performed on the connector pin pitted and identified the area as containing chromium, iron, nickel, manganese, silicon, and molybdenum. Eds was performed on the clean surface of the connector pin and identified the area as containing chromium, iron, nickel, and molybdenum. Another eds was performed on the melted surface of the connector pin and identified the area as containing chromium, iron, nickel, manganese, phosphorous, and molybdenum. It is unknown what caused the melted appearance on the connector pin surface. What appeared to be white deposits were observed in various locations. Eds was performed and identified the deposits as containing sodium, silicon, phosphorous, zirconium, and calcium. Upon visual inspection of the generator cavity no anomalies were observed. During the visual analysis the quadfilar coils appeared to be stretched, wavy and spiraled, in some areas. The connector ring quadfilar coil appeared to be burnt in half. Sem was performed and identified the burnt areas as having the appearance of being melted, with re-solidified material (evidence of being melted at one time). It is unknown exactly what caused the quadfilar coils to melt. Based on the obvious signs of mechanical damage on the coil surfaces, it is possible the openings on the outer and inner silicone tubes and the thermally-damaged coils were exposed to a high temperature device such as a cauterizing tool during the explant of this lead. The abraded opening found on the outer silicone tubing, most likely provided the leakage path for what appeared to be remnants of dried body fluids inside the outer silicone tubing. For the observed inner tubing fluid remnants, the observed location of the bare touching coils may have been a possible cause. With the exception of the observed melted areas on the connector pin and both of the quadfilar coils the condition of the returned lead portion is consistent with that which typically exists following an explant procedure. No other obvious anomalies were noted. The setscrew marks found on the lead connector pin provide evidence that a good mechanical and electrical connection was present. Continuity checks of the returned lead portion were performed, during the visual analysis, and no discontinuities were identified. Based on the findings of the pa, there is no evidence to suggest discontinuities in the returned portion of the device. The observed inner tubing openings where bare coils were touching could have potentially contributed to the low impedance and suspected short circuit condition. Note that since a small portion of the lead assembly (body) including the electrode section was not returned for analysis, an evaluation cannot be made on that portion of the lead.

https://www.accessdata.fda.gov/scripts/cdrh/cfdocs/cfmaude/detail.cfm?mdrfoi__id=2885140


Title: Re: Short Circuit
Post by: dennis100 on April 04, 2018, 12:20:53 AM
Model Number 300-20
Event Date 12/04/2012
Event Type  Malfunction   
Manufacturer Narrative
Device failure occurred but did not cause or contribute to a death or serious injury.
 
Event Description
An implant card received on (b)(4) 2013 indicated that this vns patient underwent full revision on (b)(6) 2013 due to a lead discontinuity.
 
Event Description
Lead product analysis showed that the reported mechanical problem/abraded insulation were confirmed and most likely contributed to the low impedance. During the visual analysis abraded openings were observed on the outer and inner silicone tubes and the quadfilar coils appeared to be touching and partially embedded in what appeared to be remnants of dried body tissue. The abraded openings found on the outer and inner silicone tubes, most likely provided the leakage path for what appeared to be remnants of dried body fluids found inside the outer and inner silicone tubes. With the exception of the abraded inner tubing openings and shorted quadfilar coils, the condition of the returned lead portions is consistent with those that typically exist following an explant procedure. No obvious anomalies, beyond the abraded openings and remnant of dried body tissue wrapped around the touching quadfilar coils, were noted. The setscrew marks found on the lead connector pin provide evidence that, at one point in time, a good mechanical and electrical connection was present. Continuity checks of the returned lead portions were performed, during the visual analysis, and no discontinuities were identified. Note that a break of a few strands would still allow current flow through that portion of the lead. This observation is supported by results of electrical measurements which verified continuity between the ends of this lead section. Generator product analysis showed that an end-of-service warning message was verified in the pa lab and found to be associated with the output being disabled by the pulse generator. Once the output was re-enabled, results of electrical test results demonstrated that the pulse generator was operating within specification. Burn marks were also observed on the pulse generator header, which indicated that the pulse generator may have been exposed to an electro-cautery tool during the explant procedure. Results of diagnostic testing indicated the device was operating properly. Electrical test results showed that the pulse generator performed according to functional specifications; 11. 790% of the battery had been consumed. Review of decoder data showed that the impedance on the date of generator implant ((b)(6) 2012) was 305 ohms.
 
Event Description
Product analysis was approved on (b)(6) 2013. In the pa lab, the device output signal was monitored for more than 24-hrs, while the generator was placed in a simulated body temperature environment. Results showed no signs of variation in the pulse generator's output signal and demonstrated that the device provided the expected level of output current for the entire monitoring period. The pulse generator diagnostics were as expected for the programmed parameters. The generator performed according to functional specifications. During the product analysis there were no anomalies found with the pulse generator. Surgery is likely but has not taken place.
 
Manufacturer Narrative

Event Description
On (b)(6) 2013, the patient underwent full revision. The generator was replaced to be compatible with the new lead. Diagnostics were performed without error. The products were returned and are currently undergoing product analysis.
 
Manufacturer Narrative

Event Description
During prophylactic generator revision on (b)(6) 2012, low impedance was seen in diagnostics. The pin was removed and reinserted with the same result. The surgeon noted that the silicone on the lead did not look uniform. No x-rays were taken, no manipulation or trauma was suspected, and the dcdc code on the day of surgery was 0. The explanted generator was returned on (b)(4) 2012 and is currently undergoing product analysis. Surgery is likely but has not taken place. The patient had been experiencing an increased in seizures, below pre-vns baseline as noted in clinic notes dated (b)(6) 2012. Prophylactic generator revision was performed. Attempts for additional information were unsuccessful.

https://www.accessdata.fda.gov/scripts/cdrh/cfdocs/cfMAUDE/detail.cfm?mdrfoi__id=2895237


Title: Re: Short Circuit
Post by: dennis100 on April 09, 2018, 12:48:46 AM
Model Number 102
Event Date 01/01/2013
Event Type  Injury   
Event Description
The explanted generator and lead were returned on (b)(6) 2013 and are pending product analysis.
 
Manufacturer Narrative

Event Description
Further follow-up revealed that the physician does not believe that the pain the patient was experiencing was related to vns therapy or stimulation. The patient underwent generator replacement surgery on (b)(6) 2013. Attempts to have the device returned to manufacturer for analysis are underway; however, the device has not been received to date.
 
Event Description
Clinic notes dated (b)(4) 2013 indicate that the patient has been experiencing intermittent pain in the left shoulder and neck region and that it has progressed. It was noted that the pain is more frequent and more intense and that it appears to occur with vns therapy stimulation. Additionally, it was noted that the patient now involves the patient's left arm from elbow to shoulder, the patient's left breast and the left neck and ear region. The notes indicate that x-rays of the chest and neck were performed at the patient's last visit; however, no problems with the "patency of the device or wire" were noted and it was noted that the discomfort the patient was feeling was due to scar tissue. It was noted that the device diagnostics were "normal" and that the device was programmed off. The notes indicate that the patient returned approximately two hours later with a significant decrease in pain. The physician noted that the device would be left off and that the patient would be referred for lead replacement surgery as the physician noted that there may be a short in the wire. The patient has been referred for surgery; however, the surgery has not occurred to date. Attempts to obtain additional information have been unsuccessful to date.
 
Event Description
Additional information was received that product analysis was completed on the generator and lead. Note that since a portion was not returned for analysis, an evaluation and resulting commentary cannot be made on that portion of the lead. Other than typical, wear and explant related observations, no anomalies were identified in the returned lead portion. In the pa lab, the device output signal was monitored for more than 24-hrs, while the generator was placed in a simulated body temperature environment. Results showed no signs of variation in the pulse generator¿s output signal and demonstrated that the device provided the expected level of output current for the entire monitoring period. The pulse generator diagnostics were as expected for the programmed parameters. The device performed according to functional specifications. Analysis in the pa lab concluded proper functionality of the pulse generator and that no abnormal performance or any other type of adverse condition was found. There was no dried body fluids or corrosion identified in the lead cavity or connector block area, thus eliminating the possibility of a potential unintended electrical current path through body fluids.

https://www.accessdata.fda.gov/scripts/cdrh/cfdocs/cfmaude/detail.cfm?mdrfoi__id=3010765


Title: Re: Short Circuit
Post by: dennis100 on April 13, 2018, 01:32:29 AM
Model Number 102
Event Date 05/04/2005
Event Type  Malfunction   
Event Description
Product analysis for this explanted generator was approved on (b)(4) 2013. In the pa lab, the device output signal was monitored for more than 24-hrs, while the generator was placed in a simulated body temperature environment. Results showed no signs of variation in the pulse generator's output signal and demonstrated that the device provided the expected level of output current for the entire monitoring period. The pulse generator diagnostics were as expected for the programmed parameters. To exercise the generator more strenuously, the generator was programmed to an output current of 2. 00ma, instead of the last known output current of 0. 25ma, during the monitoring test. However, a comprehensive automated electrical evaluation showed that the pulse generator is not operating according to functional specifications. The pulse generator unit failed the feed-thru capacitor tests (backup cap pos to can and backup cap neg to can). With the exception of the noted conditions, there were no adverse findings that would inhibit the product from performing as intended. The most probable root cause for the backup capacitor tests was identified to be a shorted capacitor, for which manipulation of the feed-thru wires may have been a contributing factor.
 
Manufacturer Narrative
Device manufacturing records were reviewed. Review of manufacturing records confirmed that the generator passed all functional tests prior to distribution. Device failure occurred but did not cause or contribute to a death.

https://www.accessdata.fda.gov/scripts/cdrh/cfdocs/cfmaude/detail.cfm?mdrfoi__id=2998218


Title: Re: Short Circuit
Post by: dennis100 on April 18, 2018, 12:31:19 AM
Model Number 302-20
Event Date 03/14/2013
Event Type  Malfunction   
Event Description
Analysis of the vns generator was completed. The generator performed according to functional specifications. During the product analysis there were no anomalies found with the pulse generator.
 
Manufacturer Narrative
Analysis of programming history. Device failure is suspected, but did not cause or contribute to a death or serious injury.
 
Event Description
Attempts for return of the explanted vns lead have been unsuccessful to date. The explanted vns generator was returned on (b)(6) 2013 and is pending analysis.
 
Event Description
Reporter indicated that during prophylactic vns generator replacement, low lead impedance readings were obtained with the resident lead and new generator. A short circuit of the lead was suspected due to the low impedance, and a new lead was implanted with the new generator. X-rays were not done prior to the surgery, and the patient had no known trauma and did not manipulate the vns. Review of available in-house programming history did not note any low impedance in the diagnostics history. Attempts for return of the explanted devices are in progress.

https://www.accessdata.fda.gov/scripts/cdrh/cfdocs/cfmaude/detail.cfm?mdrfoi__id=3050593



Title: Re: Short Circuit
Post by: dennis100 on April 18, 2018, 12:32:02 AM
Model Number 302-20
Event Date 11/13/2012
Event Type  Malfunction   
Event Description
Reporter indicated the vns generator and lead were replaced at the (b)(6) 2013 surgery. The explanted devices were discarded by the hospital.
 
Event Description
Reporter indicated the patient had vns generator replacement surgery performed (b)(6) 2013, but it is not clear of the vns lead was also replaced. Attempts for additional information and return of the explanted devices are in progress.
 
Event Description
Reporter indicated a patient had low lead impedance with vns systems diagnostics testing at an office visit on (b)(6) 2013. Normal mode testing was within normal limits. The patient was not feeling vns stimulation and was also experiencing increased depression below pre-vns baseline levels for the previous 4 months. The patient was seen in the office about one year previously, and at that time diagnostics were all within normal limits. The dcdc code at the previous visit was a 2 for systems, and it was currently a 0. Due to the significant drop in dcdc code and the adverse events of not feeling stimulation and increased depression, a short circuit of the lead is suspected. Reporter attributes the increased depression and not feeling stimulation to a "likely lead fracture". The patient had no trauma and does not manipulate the vns. No x-rays have been performed. Surgery to replace the lead and possibly the generator is tentatively scheduled for (b)(6) 2013.
 
Manufacturer Narrative
Device failure is suspected, but did not cause or contribute to a death or serious injury.

https://www.accessdata.fda.gov/scripts/cdrh/cfdocs/cfmaude/detail.cfm?mdrfoi__id=3044137


Title: Re: Short Circuit
Post by: dennis100 on April 19, 2018, 12:30:18 AM
Model Number 302-20
Event Date 05/07/2010
Event Type  Malfunction   
Event Description
On (b)(4) 2013 it was reported that the vns patient was continuing to have issues with shortness of breath, choking, twitching, and painful stimulation. It was reported that it was "surges felt periodically from chest area up to neck causing severe coughing episodes and pain". It was also reported that the patient's seizures are doing worse and the patient is doing poorly. The reporter stated that these issues are not constant but randomly occur sometimes with stimulation. It was stated that they have discussed this with the physician but he cannot find anything wrong with the device but that they know something is not right with the device and described "it's like there's a short in the lead". The reporter indicated that they hope the patient will get referred for replacement. It was stated that the physician has tried to make adjustments to the settings, but the patient's events have not improved or resolved. The physician later reported no causal or contributory programming or medication changes precede the onset of the adverse events. The physician stated that the patient may have a broken lead or abnormal settings. The increase in seizures were back to pre-vns baseline levels. No causal or contributory programming changes, medication changes, or other external factors precede the onset of the increase in seizures. Clinic notes were received dated (b)(6)2012 which indicate that the patient has been experiencing an increase in seizure activity and increased number of flurries during the day. It was stated that the patient is not swiping the vns magnet 3x/day. Previously it had been reported on (b)(6) 2012 that the vns patient is experiencing shortness of breath, occasional spasms in the neck with pain, and the patient believes stimulation is going off when it shouldn't. The patient stated that the events all began with the last battery replacement in 2010. System diagnostics performed on (b)(6) 2012 show the device to be functioning properly with output=ok/lead impedance=ok/dcdc=2/eri=no. The patient further clarified that "when it sporadically goes off, i fell like it's a magnet swipe". The physician believes the events are due to vns stimulation. The physician lowered the patient's pulse width and the patient was scheduled for follow-up the following day to see if any of the symptoms resolved. Further follow-up after the patient's appointment revealed that the physician is just going to give it time to see if the events resolve. The patient stated that the events are sporadic. Although surgery is likely, it has not occurred to date.
 
Event Description
On (b)(4) 2013, it was reported that the vns patient underwent generator replacement that day. The explanted generator was received for product analysis on (b)(4) 2013. It was stated that the patient had some issues with vns, that the vns wasn¿t quite working very well prior to surgery. Product analysis is underway on the generator and has not yet been completed.
 
Manufacturer Narrative

Event Description
Additional information was received on (b)(4) 2013 when product analysis was completed on the explanted generator. The septum was not cored, thus eliminating the possibility of a potential unintended electrical current path through body fluids. In the pa lab, the device output signal was monitored for more than 24-hrs, while the generator was placed in a simulated body temperature environment. Results showed no signs of variation in the pulse generator¿s output signal and demonstrated that the device provided the expected level of output current for the entire monitoring period. The pulse generator diagnostics were as expected for the programmed parameters. The generator performed according to functional specifications; there were no anomalies found with the pulse generator.

https://www.accessdata.fda.gov/scripts/cdrh/cfdocs/cfmaude/detail.cfm?mdrfoi__id=3028963


Title: Re: Short Circuit
Post by: dennis100 on April 23, 2018, 12:34:50 AM
Event Date 10/01/2001
Event Type  Malfunction   
Event Description
An article titled ¿vagus nerve stimulation after lead revision¿ was received and reviewed by the manufacturer. The authors reviewed all vns lead revisions performed between october 2001 and august 2011 at the university of hospitals and clinics. Twenty-four patients underwent 25 lead revisions. In all cases, the helical electrodes were removed, and a new lead was placed on the previously used segment of vagus nerve. All inpatient and outpatient records of the 25 lead revisions were retrospectively reviewed. All patients were treated by a single neurosurgeon. Twenty-four patients underwent 25 vns revisions between october 2001 and august 2011. Of these 25 revisions, 4 were second and 21 were first lead revisions. ¿the patients in 18 cases (72%) presented with high impedance at the time of revision, 2 cases (8%) involved a short circuit within the system, 4 cases (16%) demonstrated normal impedance, and 1 case (4%) had no implanted vns system and therefore no impedance reading since the system had been previously removed at another institution because of infection. ¿ ¿sixteen (64%) of the 18 cases with high impedance at the time of revision had no visible damage or fracture within the lead and/or cable, suggesting an intrinsic lesion within the lead and/or cable. Other causes of lead failure included visible fractures of the lead in 3 cases (12%), increasing seizure frequency and an impedance indicating a short circuit in 2 cases (8%), normal impedance but pain and shock-like sensations suspect for device malfunction in 2 cases (8%), electrode coil dislocation from the vagus nerve in 1 case (4%), and a previous hardware infection and vns system removal in 1 case (4%). ¿ symptoms varied depending on the etiology of lead failure. The patients in 18 cases (72%) presented with increased seizure frequency; in 4 cases (16%), with neck and/or chest pain, paresthesias, or shock-like sensations¿ all probably the result of a short circuit within the system; and in 6 cases (24%), with no new symptoms. Additionally, 3 cases (12%) had a history of vns-related infection, and 3 cases (12%) had a recent history of head and/or neck trauma. ¿ during lead revision surgery in all cases, the vagus nerve was found encased in fibrous scar tissue which was surgically dissected. There were no postoperative infections. ¿only 1 patient experienced a complication requiring additional surgery; in this patient the lead cable was taut, creating a pulling sensation on neck turning. " in conclusion, the authors ¿found that lead failure occurs for a variety of reasons and in our series was most commonly observed in cases of high impedance within the vns lead, which was found in 72% of [the] lead revisions. The majority of patients (89%) who presented with high impedance had no visible damage or gross fracture of the lead or cable. The etiology of high impedance and lead failure is not entirely clear in these cases. ¿ it was found that the ¿placement of a new vns lead at the previously used segment of vagus nerve provided a proper contact in all 16 such cases as well as normal impedance, implying that the presence of dense scar tissue was probably not the cause of lead failure. ¿ ¿in addition to an intrinsic increase in lead impedance and device failure, [it was] observed other factors resulting in lead failure. ¿ ¿vns lead failure most commonly resulted in an increased seizure frequency. In some cases, a very dramatic increase in seizure intensity and frequency was observed. However, other symptoms alerted patients to device malfunction and included neck and chest pain, shock-like sensations, and paresthesias. Short circuits within the system may cause these types of symptoms. ¿ the shock-like sensations, pain, and paresthesias resolved after revision. The article also noted that ¿other confounding variables include the changing antiepilepsy drugs patients potentially received over the follow-up period. Furthermore, the clinical absence of dysphonia or aspiration does not preclude the possibility of vagus nerve injury, and therefore underreporting of actual injury may be present. ¿ attempts for additional information, including patient information, have been unsuccessful to date. This report captures a patient's high impedance with no patient adverse events reported. The patient's history of vns infection is captured in mfg report number: 1644487-2013-01457. The events of high impedance accompanied with increased seizures are captured in mfg report numbers: 1644487-2013-01426, 1644487-2013-01428, 1644487-2013-01431, 1644487-2013-01432, 1644487-2013-01434, 1644487-2013-01435, 1644487-2013-01436, 1644487-2013-01443, 1644487-2013-01445, 1644487-2013-01448, and 1644487-2013-01451. The events of lead fracture accompanied with increased seizures are captured in mfg report numbers: 1644487-2013-01427 and 1644487-2013-01438. The other events of high impedance with no reported patient adverse events are captured in mfg report numbers: 1644487-2013-01429, 1644487-2013-01430, and 1644487-2013-01441. The event of high impedance due to electrode detached/dislocated from the vagus nerve is captured in mfg report number: 1644487-2013-01440. The event of high impedance accompanied with increased seizures and shock sensation is captured in mfg report number: 1644487-2013-01433. The event of postoperative ¿bowstring complication requiring surgery 1 month later¿ is captured in mfg report number: 1644487-2013-01465. The event of lead fracture (with normal lead impedance value) with no reported patient adverse events is captured in mfg report number: 1644487-2013-01458. The events of short circuit accompanied with increased seizures are captured in mfg report numbers: 1644487-2013-01442 and 1644487-2013-01455. The other events of infection are captured in mfg report numbers: 1644487-2013-01437 and 1644487-2013-01454. The events of increased seizures with one patient experiencing it with shock sensation and with one patient experiencing it with neck/chest pain are captured in mfg report numbers: 1644487-2013-01446 and 1644487-2013-01452, respectively. The event of an unknown of amount of patients with increase in seizure intensity is captured in mfg report number: 1644487-2013-01466.
 
Manufacturer Narrative
Device failure is suspected, and did not cause or contribute to a death or serious injury.

https://www.accessdata.fda.gov/scripts/cdrh/cfdocs/cfmaude/detail.cfm?mdrfoi__id=3120029


Title: Re: Short Circuit
Post by: dennis100 on April 24, 2018, 12:49:42 AM
Model Number 302-20
Event Date 02/01/2013
Event Type  Malfunction   
Event Description
It was reported that interrogation of the device resulted in high impedance >10,000 ohms. It was reported that the patient underwent generator replacement in (b)(6) 2012. The patient has been experiencing an increase in seizures and behaviors. The patient is being evaluated for replacement surgery. The patient was sent for neck and chest x-rays which were reviewed by the radiologist. The radiologist's review noted that the patient was experiencing neck pain. The review identified that the lead appears to be intact over the left lateral chest. The lead was coiled and was difficult to evaluate. Clinic notes dated (b)(6) 2013 noted that the patient's seizures have increased since the last visit in (b)(6) 2012. It was reported that the did well for several months following the last visit; however, 2 months ago she started experiencing an increase in seizures up to three to four generalized tonic-clonic seizures per week. It was also noted that the patient's mother reported that the patient's speech seems to have deteriorated and that the patient is having severe behavioral problems. The notes indicated that the recent increase in seizure frequency may be secondary to the vns malfunction. The notes indicate that the physician reduced the patient's settings from 1. 5ma/1. 8 min off to 1ma/3 min off. Attempts to obtain additional information have been unsuccessful to date. Surgery is likely; however, has not occurred to date.
 
Event Description
Further follow-up revealed that the patient underwent surgery on (b)(6) 2013. During the surgery after the patient was anesthetized, diagnostic tests resulted in normal impedance readings. The patient's head was turned in different orientations to rule out positional high impedance which were all within normal limits. Different programming systems were also used which also resulted in normal readings. The surgeon decided that he will not replace the lead since diagnostics were within normal limits. The surgery was aborted and the patient taken to recovery.
 
Manufacturer Narrative
Date received by manufacturer (mo/day/yr), corrected data: 09/09/2016. Supplemental mdr #7 inadvertently reported the incorrect aware date of 07/18/2016. The correct aware date of supplemental mdr # 7 is 09/09/2016. Date received by manufacturer (mo/day/yr), corrected data: 10/26/2016. Supplemental mdr #8 inadvertently reported the incorrect aware date of 07/18/2016. The correct aware date of supplemental mdr # 8 is 10/26/2016.
 
Manufacturer Narrative
Device failure is suspected.
 
Event Description
The explanted generator and lead were received on 10/26/2016. Proper functionality of the pulse generator in its ability to provide appropriate programmed output currents was successfully verified in the pa lab. In addition, the septum was not cored, thus eliminating the possibility of a potential unintended electrical current path through body fluids, (addressing the allegations of ¿pain¿). In the pa lab, the device output signal was monitored for more than 24-hrs, while the pulse generator was placed in a simulated body temperature environment. Results showed no signs of variation in the pulse generator¿s output signal and demonstrated that the device provided the expected level of output current for the entire monitoring period. The battery, 2. 992 volts, shows an ifi=no condition. There were no performance or any other type of adverse conditions found with the pulse generator. An analysis was performed on the returned lead portions and the reported allegations of; ¿fracture of lead(s) / explanted / due to lead break / high impedance¿ (lead section) and ¿pain¿ (lead section) were confirmed. A condition was observed that could potentially contribute to the reported ¿low impedance / low impedance message, short circuit condition¿ (lead section) allegations. The ¿increased seizures¿ (patient section) allegation is beyond the scope of activities performed in the pa laboratory environment: however, the observed discontinuities may be a contributing factor. Note that since a portion of the lead assembly including the electrodes was not returned for analysis, an evaluation and resulting commentary cannot be made on that portion of the lead. During the visual analysis abraded openings were observed on the outer and inner silicone tubes and the quadfilar coils appeared to be broken. Scanning electron microscopy was performed on the connector pin quadfilar coil break (found at 99mm) and identified the area on three of the broken coil strands as having evidence of a stress induced fracture (fatigue appearance) with mechanical damage and no pitting. The area on the remaining broken coil strand was identified as being mechanically damaged with no pitting and evidence of a stress induced fracture (rotational forces) which most likely completed the fracture. Scanning electron microscopy was performed on the connector ring quadfilar coil break and identified the areas on the broken coil strands as being mechanically damaged which prevented identification of the coil fracture type with fine pitting. Pitting was observed on the coil surface. During the visual analysis of the returned 160mm portion quadfilar coils 1 and 2 appeared to be broken. Scanning electron microscopy performed on the quadfilar coil 1 coil break identified the areas on the broken coil strands as being pitted with mechanical damage which prevented identification of the coil fracture type. Scanning electron microscopy performed on the quadfilar coil 2 coil break identified the area on three of the broken coil strands as having evidence of a stress induced fracture (fatigue appearance) with mechanical damage and no pitting and evidence of a stress induced fracture (rotational forces) which most likely completed the fracture. Determination could not conclusively be made on the fracture mechanism of the remaining quadfilar coil strand. It is believed that stimulation was present for a certain period of time as evidenced by the presence of metal pitting. Low magnification sem analysis of the quadfilar coil shows characteristics typical of a lead discontinuity which may include: material fracture, rough or pitted surface, thinned material thickness, electro-etching or material dissolution. The abraded openings found on the outer and inner silicone tubes and the cut ends that were made during the explanted process, most likely provided the leakage path for the dried remnants of what appeared to have once been body fluids found inside the outer and inner silicone tubes. What appeared to be white deposits were observed in various locations. Eds (energy dispersion spectroscopy ¿ provides chemical or element identity/composition analysis) was performed on the deposit observed on the outer silicone tubing and identified the deposit as containing silicon, phosphorus, sodium, sulphur and calcium. With the exception of the discontinuities and abraded openings, the condition of the returned lead portions is consistent with those that typically exist following an explant procedure. No other obvious anomalies were noted. The setscrew marks found on the lead connector pin provide evidence that, at one point in time, a good mechanical and electrical connection was present. Continuity checks of the returned lead portions were performed, during the visual analysis, and no discontinuities were identified. Based on the findings in the product analysis lab, there is evidence to support the ¿fracture of lead(s) / explanted / due to lead break / high impedance / low impedance / low impedance message, short circuit condition¿ allegations.
 
Event Description
On (b)(6) 2016, it was reported that low impedance with <600 ohms was observed on patient's device. Possible causes were discussed and patient manipulation was ruled out. X-rays were planned to be sent for review. Programming history for the device was reviewed. The device was temporarily disabled sometime after (b)(6) 2012 till (b)(6) 2013 due to high impedance. It is suspected that the current low impedance may be related to the previous high impedance observed in 2012. No known product replacements have occurred to date.
 
Manufacturer Narrative
Device manufacturing records were reviewed. Review of manufacturing records of the lead confirmed all quality tests were passed prior to distribution.
 
Event Description
Patient underwent full revision surgery on (b)(6) 2016. The explanted devices have not been received to date.
 
Event Description
Clinic notes were received for patient's full revision surgery referral. Notes dated 7/15/2016 indicate that the lead impedance was greater than 10,000 in 2013 and patient was referred to surgeon for a lead revision. On the day of surgery on (b)(6) 2013, intraoperative device showed that the lead impedance was not over 10,000 but rather was okay at 3069ohms. The surgeon tested the device several times with the different programming systems but all of the tests showed the lead impedance was okay and the lead impedance values ranged from 3060 to 3179 ohms. As a result, the surgeon did not revise the lead at that time. More recently, patient was seen by the neurologist and the lead impedance was less than 600 ohms, and so patient was referred back to surgeon for evaluation and management. A chest x-ray was performed, which showed a lead fracture. According to caregiver, patient's seizures have been increasing in frequency. Patient had done quite well over the past couple of years, but more recently, within the past six months, experienced an increase in seizure frequency. Patient has had no real behavioral concerns until just recently likely related to the vns not working because of the lead fracture. Lead revision is planned but has not occurred to date.
 
Manufacturer Narrative
Describe event or problem: supplemental mdr #3 incorrectly reported that the high impedance was observed in 2012, when in fact, it was only observed in 2013.
 
Event Description
Lead product information was received.

https://www.accessdata.fda.gov/scripts/cdrh/cfdocs/cfmaude/detail.cfm?mdrfoi__id=3115964


Title: Re: Short Circuit
Post by: dennis100 on May 04, 2018, 11:36:23 PM
Model Number (11)150331
Event Date 08/19/2016
Event Type  Injury   
Event Description
Cyberonics vns magnet model 220 implant on (b)(6) 2016. (b)(6) 2016 device short circuited causing potential damage to vagal nerve. Patient felt extreme heat and could not move for 24 hours. Device then shut off, had to be surgically removed and replaced on (b)(6) 2016. Picture of malfunction device shows bubble that formed to interfere with wires. Device sent back to cyberonics. Lot number 1464006.

https://www.accessdata.fda.gov/scripts/cdrh/cfdocs/cfmaude/detail.cfm?mdrfoi__id=7424951


Title: Re: Short Circuit
Post by: dennis100 on May 09, 2018, 12:58:28 AM
Event Date 09/11/2013
Event Type  Malfunction   
Manufacturer Narrative
Device failure is suspected, but did not cause or contribute to a death or serious injury.
 
Event Description
A vns nurse reported that the patient was observed to have an impedance reading of 774 ohms. Per the nurse's copy of the data card, it appeared there was a reduction in impedance over time. Per the programming history, system diagnostics show that the impedance value is between 2315 ohms and 2422 ohms from (b)(6) 2010 to (b)(6) 2011. The last recorded system diagnostic had an impedance value of 1147 ohms. Follow up with the nurse found that no x-rays were planned as they did not see the point. It is believed that the patient's device may have migrated into her breast at one point as the patient grew. Revision surgery is being discussed for the possible short circuit. No other information has been provided. Although surgery is likely, it has not occurred to date.

https://www.accessdata.fda.gov/scripts/cdrh/cfdocs/cfmaude/detail.cfm?mdrfoi__id=3405904


Title: Re: Short Circuit
Post by: dennis100 on May 15, 2018, 07:50:33 AM
Model Number 302-20
Device Problem No Known Device Problem
Event Date 01/01/2014
Event Type  Malfunction   
Manufacturer Narrative
Device failure is suspected, but did not cause or contribute to a death. Adverse event and/or product problem; corrected data: additional information indicates that lead discontinuity was causing the patient¿s pain. Brand name; corrected data: additional information indicates that the suspect device is the lead. Type of device, name; corrected data: additional information indicates that the suspect device is the lead. Model #, serial #, lot#, expiration date; corrected data: additional information indicates that the suspect device is the lead. Type of reportable event; corrected data: additional information indicates that lead discontinuity was causing the patient¿s pain. Device manufacture date; corrected data: additional information indicates that the suspect device is the lead.
 
Event Description
An implant card was received indicating that the vns patient underwent generator and lead replacement surgery on (b)(6) 2014 due to lead discontinuity. Further follow-up revealed that the patient underwent surgery for patient comfort and not to preclude a serious injury. Patient manipulation or trauma is not believed to have caused or contributed to the lead discontinuity. The patient¿s pain was occurring with stimulation and due to lead discontinuity. The explanted products have not been returned to date.
 
Manufacturer Narrative
Describe event or problem, corrected data: this information (spasms, fatigue, nausea) was inadvertently not included in the initial mfr. Report. Describe event or problem, corrected data: this information (pain, coughing) was inadvertently not included in the mfr. Supplement report #3. Additional manufacturer narrative, corrected data: mfr. Supplemental report #2 should have included the description of the corrected data as "describe event or problem, corrected: this information was inadvertently not included in the initial mfr. Report. ".
 
Event Description
It was reported that the patient experienced abdomen and chest spasms, fatigue and nausea. The patient experienced pain and coughing at the time of device interrogation.
 
Event Description
Surgical notes dated (b)(6) 2014 indicated that the vns was malfunctioning and that the patient underwent generator and lead replacement.
 
Event Description
The patient¿s pain was occurring with stimulation and due to lead discontinuity. The lead discontinuity is likely due to a short circuit situation (dcdc code = 0).
 
Event Description
It was reported that the vns patient was experiencing very painful side-effects from vns. Further follow-up with the patient revealed that the patient was experiencing pain on the left side of her neck that radiated up to her temple. This mostly occurred through the patient¿s jaw and roof of her mouth causing headaches. The patient was most uncomfortable at night and when she was lying down. The patient later reported that the pain was getting worse and that she was feeling sick and panicking. The patient¿s device was eventually programmed off on (b)(6) 2014 despite it being effective in treating the patient¿s depression. The patient was referred for generator and lead replacement surgery due to severe headaches and neck spasms. The patient¿s normal mode output current was programmed off and system diagnostic results showed normal device function. No known interventions have occurred to date.

https://www.accessdata.fda.gov/scripts/cdrh/cfdocs/cfmaude/detail.cfm?mdrfoi__id=3808957


Title: Re: Short Circuit
Post by: dennis100 on August 07, 2018, 12:53:43 AM
Model Number 102
Event Date 01/01/2007
Event Type  Injury   
Event Description
Additional info was received from the pt indicating she continued to have a hurting sensation in the neck area where the electrodes were. The pt indicated that the event had been occurring ever since vns implant and her implanting physician would not remove her electrodes. Further info from a company rep indicated the pt was scheduled to see a surgeon for explant consult. F/u was made with the surgeon's office and indicated the pt is scheduled to undergo vns generator removal surgery as the pt complains of pain at the generator site. The pt's device is off and pt wants it out. The surgeon's office indicated the surgery was to preclude a serious injury and had no additional info regarding the pt's treating neurologist. Additional info from the surgeon's office indicated the pt underwent generator removal surgery as scheduled. Good faith attempts to obtain the explanted generator have been unsuccessful to date.
 
Event Description
Additional information was received from the patient on 12/21/2017 that the vns would constantly hurt her in the chest and where the wires were in the neck. She stated it started shorting out years prior. After the battery died it was still hurting her until she had it removed. She stated there was too much scar tissue in the neck on the electrodes and could not be completely removed. Additional relevant information has not been received to-date.
 
Event Description
Follow-up from the physician provided that the vns had served the patient well but that the patient had other underlying issues and offered to remove her vns.

https://www.accessdata.fda.gov/scripts/cdrh/cfdocs/cfmaude/detail.cfm?mdrfoi__id=1959461


Title: Re: Short Circuit
Post by: dennis100 on August 10, 2018, 03:00:12 AM
Model Number 304-20
Device Problem Low impedance
Event Date 06/28/2018
Event Type  Malfunction   
Manufacturer Narrative

Event Description
It was reported that a low impedance warning message was observed on the patient's vns. A low impedance warning typically indicates that a short circuit condition may be occurring. No relevant surgeries are known to have occurred to date. No additional relevant information has been received to date.

https://www.accessdata.fda.gov/scripts/cdrh/cfdocs/cfmaude/detail.cfm?mdrfoi__id=7726573


Title: Re: Short Circuit
Post by: dennis100 on September 07, 2018, 08:45:04 AM
Model Number 302-30
Device Problem Low impedance
Event Date 01/26/2010
Event Type  Malfunction   
Manufacturer Narrative

Event Description
It was reported that the physician believed that there was a malfunction with the patient's vns lead due to the impedance being lower than expected, although still within "normal" limits. This was believed to be the case because the patient's settings were very high, and the physician expected higher impedance results. The impedance values of the patient's previous devices were within a similar range. The patient had multiple vns devices implanted due to battery depletion related to the high settings. Historical data was reviewed for all of the vns devices that the patient had been implanted with, and the patient's third generator showed a slight drop in impedance range from dcdc 1 to dcdc 0. Based on the physician's suspicion of a possible short circuit condition and the review of historical data, there is a possibility of a lead malfunction. The physician previously referred the patient for full revision surgery to get better electrode contact on the nerve, but the surgeon decided to only replace the generator as the impedance was within normal limits. The explanted generator was not returned to the manufacturer for analysis. The physician referred the patient again for full revision surgery due to a suspected lead malfunction, but no surgery has occurred to date. No further relevant information has been received to date.

https://www.accessdata.fda.gov/scripts/cdrh/cfdocs/cfmaude/detail.cfm?mdrfoi__id=7772865


Title: Re: Short Circuit
Post by: dennis100 on October 05, 2018, 12:09:27 PM
Model Number 106
Device Problem Premature End-of-Life Indicator
Event Date 03/21/2016
Event Type  Malfunction   
Manufacturer Narrative

Event Description
It was reported that patient's device was showing eos yes after only being implanted for two years. The patient¿s settings were still at 0ma due to the eos pulse disablement. A review of device history records for the generator shows that no unresolved non-conformances were found. Internal investigation determined that this behavior was likely related to an increased duration of the high battery impedance experienced by batteries during the beginning of life (bol) or an internal short that managed to ¿burn¿ itself out.

https://www.accessdata.fda.gov/scripts/cdrh/cfdocs/cfmaude/detail.cfm?mdrfoi__id=7920766


Title: Re: Short Circuit
Post by: dennis100 on October 06, 2018, 04:37:47 AM
Model Number 304-20
Event Date 08/09/2016
Event Type  Malfunction   
Event Description
It was reported that a patient had low impedance results on his first follow-up visit following initial implant. Two system diagnostics were performed and showed low impedance. There was reportedly no trauma that had occurred since implant, but the patient reportedly felt a "heat sensation all day" at one point. The patient reported that they had still experienced coughing when the settings were increased. It was noted that impedance values were intermittently within normal limits pre-operatively. When the patient's position changed, he sometimes got impedance values in normal limits and other times got low impedance. The physician reported that he saw a "bubble" in the connector cavity that he believed was causing the low impedance. The surgeon opted to perform generator replacement and leave the lead intact. The explanted generator has not been received to date. No further relevant information has been received to date.
 
Event Description
After the patient's generator replacement surgery on (b)(6) 2016, the impedance values were within normal limits. It was reported that the explanted generator would not be returned for analysis per the explant facility's policy. X-rays were provided to the manufacturer for review. The a/p chest x-ray showed that the lead pin was fully inserted into the connector block, the feedthru wires appeared intact at the connector block, and the generator was placed normally in the left chest just below the clavicle. A portion of the lead was found routed behind the generator. No gross lead discontinuities were identified, no sharp angles were identified, and the lead appeared intact at the connector pin. An assessment could not be made on the portion of the lead routed behind the generator. Therefore, the presence of a microfracture and any additional information regarding the lead portion behind the generator cannot be assessed. No additional relevant information has been received to date.
 
Event Description
Full analysis was completed on the generator and confirmed its ability to accurately measure impedance values. The device was placed in a simulated body environment and the generator showed no signs of variation in the output signal and demonstrated the expected level of output current. The generator was subjected to multiple electrical loads and verified the ability to accurately measure impedance values within an appropriate range. The generator septum was visually analyzed and verified that it was not cored. No other surface anomalies were identified on the generator. The generator performed according to all functional specifications with respect to accurately measuring impedance values.
 
Manufacturer Narrative
(b)(4).
 
Event Description
The explanted generator was returned and had product analysis completed, verifying that the generator was able to accurately measure impedance values. This verified that there was an intermittent short circuit in the lead. Negative impedance values were measured when there was a 0 ohm load applied to the generator.
 
Event Description
The explanted generator was returned for analysis. Historical diagnostic data was also provided and reviewed. Historical found the date that the low impedance message was first identified and verified that the impedance had bounced back up as previously reported to about 2,000 ohms at one time. The explanted generator is currently undergoing analysis.
 
Manufacturer Narrative
Describe event or problem, corrected data: the initial report inadvertently did not include information regarding post generator replacement. Relevant tests/laboratory data, including dates: the initial report inadvertently did not include the post generator replacement impedance value.
 
Manufacturer Narrative
Describe event or problem, corrected data: supplemental report #1 inadvertently did not include notice that the generator had been returned.

https://www.accessdata.fda.gov/scripts/cdrh/cfdocs/cfmaude/detail.cfm?mdrfoi__id=5950353


Title: Re: Short Circuit
Post by: dennis100 on October 18, 2018, 01:20:02 AM
Model Number 302-20
Event Date 08/29/2012
Event Type  Malfunction   
Manufacturer Narrative
Device failure occurred, but did not cause or contribute to a death or serious injury.
 
Manufacturer Narrative
Device failure is suspected but did not cause or contribute to a death or serious injury.
 
Event Description
Additional information was received on (b)(6) 2012 when product analysis was completed on the explanted generator. The generator performed according to functional specifications. Product analysis on the generator was completed on (b)(6) 2012. During the product analysis there were no anomalies found with the pulse generator. The abraded openings found on the outer and inner silicone tubes, most likely provided the leakage path for what appeared to be remnants of dried body fluids found inside the outer and inner silicone tubes. What appeared to be white deposits were observed in various locations. Eds (energy dispersion spectroscopy - provides chemical or element identity/composition analysis) was performed on the same type of white deposits found during the visual analysis of similar lead products and identified them as containing silicon, calcium, sodium and phosphorus. The abraded openings on two adjacent sections of inner tubing created a condition whereby the exposed conductive coils could come in contact with each other and creating a potential short-circuit condition. The condition of the returned lead portions is consistent with those that typically exist following an explant procedure. No other obvious anomalies, beyond the abraded openings, were noted. The setscrew marks found on the lead connector pin provide evidence that, at one point in time, a good mechanical and electrical connection was present. Continuity checks of the returned lead portions were performed, during the visual analysis, and no discontinuities were identified.
 
Event Description
On (b)(6) 2012, it was reported that the vns patient was scheduled for a prophylactic battery replacement on (b)(6) 2012; however, during surgery, the lead was determined to need replacement due to the lead being frayed and the wires exposed. The surgeon later stated that system diagnostics from surgery showed dcdc=0 and lead impedance=ok. No x-rays were taken prior to surgery. No patient manipulation or trauma occurred that is believed to have caused or contributed to the lead fraying/wires exposed. The explanted lead and generator were returned for product analysis on (b)(6) 2012. Product analysis is still underway and has not yet been completed. The reason for explant on the form received with the explanted products indicated that the housing on the leads were frayed and the wires were exposed. Clinic notes dated (b)(6) 2012 were received, which indicate that the patient's mother has not noticed the patient's voice changing at all lately with activation of the magnet. Clinic notes dated (b)(6) 2011, stated that the patient's vns was interrogated and settings left unchanged but the physician was unable to perform a lead test due to poor patient cooperation. The patient was referred for prophylactic generator replacement since the patient was reaching end of service. The patient's programming history was reviewed and all the system diagnostics tests showed results within normal limits and all showed a dcdc of 0 except for one date ((b)(6) 2005) that showed a dcdc of 2.

https://www.accessdata.fda.gov/scripts/cdrh/cfdocs/cfmaude/detail.cfm?mdrfoi__id=2755718


Title: Re: Short Circuit
Post by: dennis100 on November 08, 2018, 01:18:31 AM
Model Number MODEL 250
Event Date 12/20/2012
Event Type  Malfunction   
Event Description
Reporter indicated that the pins located on the handheld computer were bent and that the flashcard was unable to be inserted. The physician indicated that there was nothing that could have occurred that would have caused the pins to become bent nor were there any accidental attempts to place the flashcard in the handheld backwards. The handheld was returned to device manufacturer for analysis on (b)(6) 2013; however, analysis has not yet been completed to date.
 
Event Description
Two flashcards were returned on (b)(6) 2013 and analyzed with the handheld. Visual analysis of the handheld verified that five of the flashcard slot pins were bent. The cause of the bent pins is associated with mishandling of the device. Once the pins were straightened, no anomalies associated with the handheld performance were noted. Analysis of the flashcards revealed that the 8. 1 version flashcard had 3 bent pins and as a result of the bent pins, the returned handheld would freeze when the flashcard was inserted. Once the electrical shorts were removed and the pins were repaired, not further anomalies were identified. The 8. 0 version flashcard had no anomalies associated and performed according to functional specifications.
 
Manufacturer Narrative
 
Manufacturer Narrative
Device failure occurred, but did not cause or contribute to a death or serious injury.

https://www.accessdata.fda.gov/scripts/cdrh/cfdocs/cfmaude/detail.cfm?mdrfoi__id=2902159


Title: Re: Short Circuit
Post by: dennis100 on December 03, 2018, 04:00:39 AM
Model Number 103
Event Date 03/31/2016
Event Type  Malfunction   
Manufacturer Narrative
(b)(4).

Event Description
It was reported that this patient's generator was replaced, and the explanted generator was discarded after surgery. No other relevant information has been received to date.

Event Description
It was reported that diagnostic tests were taken on the generator prior to implanting of device outside of the pocket and after device was in the pocket. The test before implant showed the battery was not at near end of service condition, but the test after the generator was in the pocket showed that the device was at end of service condition. It was reported that the generator was not cold prior to implant. The physician decided to continue implanting the generator. The manufacturer's or specialist that attended the surgery did not see cautery come in contact with the generator, but the cautery device was lying on the patient when the generator was introduced. The surgeon also submerged the generator in a tray with antibiotic solution prior to implant. The manufacturer investigated the programming data available from surgery. The voltage dropped from 3. 287v to 1. 884v during the surgery. The initial interrogation (before implant) and system diagnostics were at ifi = no, and the subsequent diagnostics (after implant) measured between 1. 884v and 1. 988v. The drop in voltage is an indicator that the device likely came in contact with an electro-cautery device or an electrostatic discharge, causing the asic latch-up condition. Electro-cautery is known to potentially cause battery depletion and its usage is warned against in labeling. No known surgical intervention has occurred to date.

https://www.accessdata.fda.gov/scripts/cdrh/cfdocs/cfmaude/detail.cfm?mdrfoi__id=5594516


Title: Re: Short Circuit
Post by: dennis100 on December 03, 2018, 04:02:00 AM
Model Number 103
Device Problems Premature End-of-Life Indicator; Defective Device; Device Displays Incorrect Message
Event Date 06/10/2015
Event Type  Malfunction   
Event Description
An user facility medwatch was received on 10/05/2015 reporting an unspecified error during device replacement requiring a second procedure. The medwatch report date was 07/07/2015 via the fda's medwatch program and report # was mw5044181.

Event Description
It was reported that the company representative observed end of service vbat < eos message on two different programmers. The hospital registered nurse reported that it is possible that the resident used bovie electrocautery. If electrocautery comes in contact around the generator, this is a known cause for premature end of service of the battery.

Event Description
A copy of the programmer data from the surgery was reviewed. The device was interrogated on date of implant and was set to 1. 5ma. The battery status indicator was already revealing near end of service (neos) = yes. It was reported that the device was off at time of implant. Review of the generator device history record was performed and confirmed that all quality specifications were passed prior to distribution. No anomalies were observed during the manufacturer process, and the device was confirmed to be set to 0ma at time of manufacturer release.

Manufacturer Narrative

Event Description
It was reported that the patient had generator replacement on (b)(6) 2015, and was seen post-operatively to turn on the replacement device, but a near end of service (neos) message was observed upon interrogation. The surgeon reported that electro-cautery was not used in proximity to the generator during surgery. He felt that the generator was defective. The generator was subsequently replaced the same day. The explanted generator has not been received to date by the manufacturer for analysis. The hospital¿s policy is to keep explanted devices. Good faith attempts for additional, relevant information have been unsuccessful to date.

Manufacturer Narrative
The user facility medwatch report received was identified to be related to the event previously reported within this manufacturer report which reported the events and device information previously. (b)(4). Based on the investigation, the premature end of life of the generator is suspected asic latch-up as a result of electrocautery during implant surgery. However, a definitive conclusion cannot be made, as the explanted generator was not received by the manufacturer for analysis. Good faith attempts for product return have been unsuccessful. This event is addressed in labeling and is due to asic latch-up. Per section 1. 6. 4. 1 of the vns therapy system physician's manual (u. S. ), "use of electrosurgery (electrocautery or radio frequency [rf] ablation devices) may damage the pulse generator. During the vns implantation procedure, do not use electrosurgical equipment after the pulse generator has been introduced to the sterile field. [. ] electrostatic discharge (esd) may damage the pulse generator. Care should be taken when using the hex screwdriver to avoid touching the metal shaft when the screwdriver is engaged with the setscrew of the pulse generator. This shaft can serve as a path to conduct electrostatic discharges into the device circuitry. ".

https://www.accessdata.fda.gov/scripts/cdrh/cfdocs/cfmaude/detail.cfm?mdrfoi__id=4874583


Title: Re: Short Circuit
Post by: dennis100 on December 03, 2018, 04:02:44 AM
Model Number 103
Event Date 02/01/2010
Event Type  Malfunction   
Event Description
It was reported that a vns patient's generator was explanted due to high lead impedance. The explanted generator was returned to the manufacturer and underwent product analysis. Product analysis performed on the returned generator revealed an end of service warning message which was associated with the output being disabled by the pulse generator. Once the output was re-enabled the following was observed: electrical test showed that the pulse generator was operating within specification. There were no adverse functional, mechanical, or visual issues identified with the returned generator. The reported eos condition was not duplicated during the pa analysis. Capa (b) (4) further investigated the eos condition of the generator and revealed the root cause of the eos warning messages as being an asic latch-up condition resulting from the pulse generator receiving an electrical transient during implant surgery. The electrical transient is the result of electromagnetic induction (emi) or electrostatic discharge (esd). This emi and/or esd causing the asic latch-up can be attributed to: the use of monopolar electrosurgery in direct contact with the pulse generator; monopolar electrosurgery in close vicinity to the pulse generator; or a major electrostatic discharge.

https://www.accessdata.fda.gov/scripts/cdrh/cfdocs/cfmaude/detail.cfm?mdrfoi__id=1702210


Title: Re: Short Circuit
Post by: dennis100 on December 03, 2018, 04:03:45 AM
Model Number 103
Event Date 08/22/2016
Event Type  Malfunction   
Event Description
Analysis of the returned generator was completed. It indicated that the reported allegation of ¿asic latch-up condition¿, could be verified in the pa laboratory. Review of the data downloaded from the pulse generator indicated that the pulsedisabled byte was set to a value that represents a vbat

Event Description
Further information from the surgeon was received indicating that during the surgery, an equipment could have touched the device, which could have caused the premature end of service. The explanted generator was returned to the manufacturer on 10/31/2016. Analysis is underway but it has not been completed to date.

Manufacturer Narrative
(b)(4).

Event Description
It was reported that a physician could not interrogate a vns patient's device on (b)(6) 2016. It was reported that the day before, on (b)(6) 2016, the patient underwent surgery due to infection where the wound was cleaned without explanting the device (event reported in the medwatch report 1644487-2016-02050). Before the surgery, the device was switched off without any issues. The physician did not perform a diagnostics test, but there was no issue with the patient's generator. After the surgery, when the physician tried to switch the device back on (on (b)(6) 2016), communication issues occurred. The physician tried many times before she could finally interrogate the generator. It then stated that the generator was at end of service. The device was implanted in (b)(6) 2016 (2 months ago). Diagnostics test showed: low output current, impedance ok, 2806 ohm, eos yes. It was reported that another physician came to help using her programming system, but she could never communicate with the device. Review of manufacturing records confirmed that the generator passed all functional tests prior to distribution. Further information from the physician indicated that, 10 days after the surgery they still could not interrogate the patient's generator. As the infection was still there, it was decided to explant the device. It was reported that the patient underwent explant surgery on (b)(6) 2016. The return of the explanted device is expected but it has not been received to date.

https://www.accessdata.fda.gov/scripts/cdrh/cfdocs/cfmaude/detail.cfm?mdrfoi__id=5948700


Title: Re: Short Circuit
Post by: dennis100 on December 03, 2018, 04:04:25 AM
Model Number 103
Event Date 11/09/2009
Event Type  Malfunction   
Event Description
It was reported that a vns pt's generator was explanted due to pain at the generator site. The explanted generator was returned to the mfr and underwent product analysis. Product analysis performed on the returned generator revealed an end of service warning message which was associated with the output being disabled by the pulse generator. Once the output was re-enabled, the following was observed: electrical test showed that the pulse generator was operating within specification. There were no adverse functional, mechanical, or visual issues identified with the returned generator. The reported eos condition was not duplicated during the pa analysis. Capa (b)(4) further investigated the eos condition of the generator and revealed the root cause of the eos warning messages as being an asic latch-up condition resulting from the pulse generator receiving an electrical transient during implant surgery. The electrical transient is the result of electromagnetic induction (emi) or electrostatic discharge (esd). This emi and/or esd causing the asic latch-up can be attributed to: the use of monopolar electrosurgery in direct contact with the pulse generator; monopolar electrosurgery in close vicinity to the pulse generator; or a major electrostatic discharge. The pain event is further reported in mfr report # 1644487-2009-02675 along with the product analysis of the generator.

https://www.accessdata.fda.gov/scripts/cdrh/cfdocs/cfmaude/detail.cfm?mdrfoi__id=1614971


Title: Re: Short Circuit
Post by: dennis100 on December 03, 2018, 04:05:05 AM
Model Number 103
Event Date 03/01/2010
Event Type  Malfunction   
Event Description
It was initially reported by the surgeon that the patient is having his battery replaced due to eos. Patient's eri status showed that only one month is remaining. Explanted generator was returned to manufacturer for analysis. Analysis was completed by the manufacturer. Product analysis of the returned generator revealed that an end of service warning message was received and found to be associated with the output being disabled by the pulse generator. Once the output was re-enabled, the reported demipulse eos condition was duplicated during diagnostic testing, using parameters from the programming history, which indicated that the generator was approaching eos, (1 month at the returned parameters). There were no adverse functional, mechanical, or visual issues identified with the returned generator. Additional information received from the surgeon's nurse revealed that electrocautery was used during explant of the generator. She did not know the specifics of the electrocautery. Further investigation determined that the root cause of the eos warning messages as being an asic latch-up condition resulting from the pulse generator receiving an electrical transient during implant surgery. The electrical transient is the result of electromagnetic induction (emi) or electrostatic discharge (esd). This emi and/or esd causing the asic latch-up can be attributed to: the use of monopolar electrosurgery in direct contact with the pulse generator; monopolar electrosurgery in close vicinity to the pulse generator; or a major electrostatic discharge.

https://www.accessdata.fda.gov/scripts/cdrh/cfdocs/cfmaude/detail.cfm?mdrfoi__id=1711607


Title: Re: Short Circuit
Post by: dennis100 on December 03, 2018, 04:06:07 AM
Model Number 104
Event Date 07/02/2013
Event Type  Malfunction   
Manufacturer Narrative
End of service message seen upon interrogation of the pulse generator.

Event Description
It was reported that the patient was in the operating room under anesthesia for prophylactic generator replacement, it was observed that the replacement model 104 device was at ifi (intensified-follow-up condition) with ifi=yes observed during when pre-operatively, the device was at 100% battery capacity. Therefore, the model 104 replacement device was also explanted, and not used. Troubleshooting was performed during surgery. The company representative observed the surgeon use electrocautery during the original explant, but was unable to verify if it was used with the replacement model 104 device was placed. The surgeon reported that he was not sure if he used electrocautery in the vicinity of the replacement device, as surgery is a complicated process. No other issues were reported from the surgery. The patient was implanted with another generator successfully. The unused generator was returned to the manufacturer for analysis. However, product analysis has not been completed to date. Additionally, a copy of the programming/diagnostic data from the surgery was copied by the company representative, but the data has not been uploaded/reviewed to date. If electrocautery was used in the vicinity of the replacement generator, the asic latch-up condition may have occurred where the errrant end of service conditions may be due to the asic remaining in a trickle charge state when an undeliverable output current is programmed.

Event Description
Analysis of the generator was completed on (b)(6) 2013. An end-of-service warning message was verified in the pa lab and found to be associated with the output being disabled by the pulse generator. Once the output was re-enabled, results of electrical test results demonstrated that the pulse generator was operating within specification. Burn marks on the generator case suggest it was exposed to high energy such as an electro-cautery system during the attempted implant. Results of diagnostic testing indicated the device was operating properly. Following a re-enable of the generator output, electrical test results showed that the pulse generator performed according to functional specifications.

https://www.accessdata.fda.gov/scripts/cdrh/cfdocs/cfmaude/detail.cfm?mdrfoi__id=3248849


Title: Re: Short Circuit
Post by: dennis100 on December 04, 2018, 01:58:55 AM
Model Number 103
Event Date 04/10/2009
Event Type  Malfunction   
Manufacturer Narrative
Date received by manufacturer (mo/day/yr), corrected data. Follow-up report #1 inadvertently listed the aware date as (b)(6) 2011, which was the aware date for the initial report. The correct aware date for the follow-up #1 report should have been (b)(6) 2011.

Event Description
A review of pt programming data revealed that during the pt's initial follow up visit ((b)(6) 2009) after implant surgery ((b)(6) 2009) a "vbat < eos threshold" warning message was received indicating that the pt's demipulse generator was likely in the presence of electrocautery causing an asic latch-up condition during the implant procedure. As a result of this exposure the capacity of the generators battery was altered leading to an atypical depletion state. The generator was returned and reported in mdr # 1644487-2011-01531 due to a premature eos allegation. An end-of-service warning message was verified in the product analysis lab and found to be associated with the output being disabled by the pulse generator. Post burn-in electrical test results showed that the pulse generator performed according to functional specifications. There was a capacitor that was measured to be out-specification but had no adverse effect on device functionality. The battery is depleted, 1. 56 volts as measured with the can removed and battery still attached to the pcb. The data in the memory locations revealed that 34. 928% of the battery had been consumed.

Event Description
Attempts were made for operative notes for the implant and explant of the generator however they will not be provided as it is against their policy.

https://www.accessdata.fda.gov/scripts/cdrh/cfdocs/cfmaude/detail.cfm?mdrfoi__id=2211867


Title: Re: Short Circuit
Post by: dennis100 on January 16, 2019, 01:36:46 AM
Model Number MODEL 250
Event Date 04/08/2014
Event Type  Malfunction   
Event Description
It was reported that the physician's handheld will not power on and the charge light does not illuminate when the unit is plugged into the ac power cord. A known working power cord was used and the charge light would still not illuminate and the handheld would not power on. The lock button was not engaged. The physician was provided a new programming tablet and the handheld and flashcard were returned for analysis. Analysis of the handheld was completed on (b)(4) 2014. No anomalies associated with the main battery were identified during the analysis. During the analysis it was identified that the handheld would not power on. The cause for the identified anomaly is associated with an open fuse in the handheld. Once the fuse was replaced no anomalies associated with the handheld were noted during testing using the ac adapter or the main battery with a full charge. The cause for the open fuse is most likely related with an electrical short caused by the damaged record button on the side of the handheld. No other anomalies were identified. Analysis of the flashcard was completed on (b)(4)2014. No anomalies associated with flashcard software or databases were identified during the flashcard analysis. The flashcard and software performed according to functional specifications.
 
Manufacturer Narrative
Device failure occurred, but did not cause or contribute to a death or serious injury.
 
Event Description
Clinic notes were received dated (b)(6) 2014 for the patient. Per the notes, the patient was in to see the physician for a follow up evaluation for seizures. During the visit, the clinic notes stated that the patient's generator was not able to be interrogated due to "technical issues". Through additional investigation, the physician confirmed that these "technical issues" were referring to the reported event of the hand held programming device not being able to power on, which was reported in mfr report # 1644487-2014-01221.

https://www.accessdata.fda.gov/scripts/cdrh/cfdocs/cfmaude/detail.cfm?mdrfoi__id=3800223


Title: Re: Short Circuit
Post by: dennis100 on January 17, 2019, 02:12:41 AM
Model Number 102R
Event Date 04/13/2016
Event Type  Malfunction   
Manufacturer Narrative
Brand name; corrected data: this information was inadvertently reported incorrectly on the initial mfr. Report. Type of device; corrected data: this information was inadvertently reported incorrectly on the initial mfr. Report. Model #, serial #, lot#, exp. Date, and other; corrected data: this information was inadvertently reported incorrectly on the initial mfr. Report. Operator of device; corrected data: this information was inadvertently reported incorrectly on the initial mfr. Report. If implanted, give date; corrected data: this information was inadvertently reported incorrectly on the initial mfr. Report.
 
Event Description
It was reported the patient underwent generator replacement surgery on (b)(6) 2016. It was noted the company representative tested the new m104 generator and diagnostics showed a dcdc value of 2, which is within normal limits. The surgeon asked the company representative why they were doing a lead revision and the company representative explained that is what the physician requested. The patients neck was somewhat contracted and the surgeon was concerned that he wouldn't be able to get adequate exposure to complete the revision. The surgeon spoke with the physician and the decided to only do a generator replacement and they did not replace the lead. Additional diagnostics were run with the patient's head in 3 different positions to rule out lead discontinuity. The surgeon was satisfied. The m104 generator was then attached to the existing lead, diagnostics were checked and found to be normal, and the generator was left off per the surgeon's request. The explanted generator was received by the manufacturer for analysis; however, analysis has not been completed to date. The returned product form (rpf) stated the generator was replaced prophylactically. The implant card was received by the manufacturer and showed that after the new m104 generator was placed, diagnostics showed 2380 ohms, which was within normal limits. Attempts for additional information have been unsuccessful to date.
 
Manufacturer Narrative
Brand name; type of device; model#, serial#, lot#, other; operator of device; if implanted, give date; corrected data: this information was incorrectly reported on the initial mfr. Report.
 
Event Description
It was reported by the physician that the patient's device was found to be programmed to 0ma output current on (b)(6) 2016. It was noted the patient was previously seen on (b)(6) 2016 and the device had been programmed to 2. 75ma, diagnostic results were ok, and the device was interrogated prior to the patient leaving the appointment. The physician tried to re-program the patient to 1. 25ma, but the patient gagged, and when he re-interrogated the device, it was set to 0ma again. The physician stated he was going to leave the patient off after learning that low impedance could be a short circuit, and leave the device programmed off because the patient gagged. It is unknown if low impedance was actually observed. The programming history database was reviewed and a battery life calculation was performed; however, the information available only went to 10/08/2014 and was not relevant to the issues which were observed in april and may of 2016. Attempts for additional relevant information have been unsuccessful to date.
 
Event Description
Product analysis was performed on the returned generator. The device output current was monitored for more than 24-hours while the generator was placed in a simulated body temperature environment. Results showed no signs of variation in the generator's output signal and demonstrated the device provided the expected level of output current for the entire monitoring period. The generator diagnostics were as expected for the programmed parameters. The generator performed according to functional specifications. There were no performance or any other type of adverse conditions found with the generator. Additionally programming history was received into the in-house programming history database and was reviewed. It was found that generator diagnostics were run, which programmed the device off. This is an expected event after running generator diagnostics. It was noted that the physician changed the patient's setting back, but then ran generator diagnostics again, causing the device to be programmed off once again. Generator diagnostics should only be run in the or while using a test resistor, prior to implanted the device into the patient. All other diagnostic results showed the generator was working properly.

https://www.accessdata.fda.gov/scripts/cdrh/cfdocs/cfmaude/detail.cfm?mdrfoi__id=5743402


Title: Re: Short Circuit
Post by: dennis100 on February 13, 2019, 01:27:02 AM
Model Number 302-20
Event Date 01/23/2015
Event Type  Malfunction   
Event Description
The explanted lead was returned for analysis on (b)(4) 2015. Product analysis for the lead was completed and approved on (b)(4) 2015. An analysis was performed on the returned lead portions and a condition was observed that could potentially contribute to the reported ¿low impedance / low impedance message, short circuit condition¿ (lead section) allegations. The bare and exposed conductive coils may be a contributing factor. Note that since a portion of the lead assembly including the electrodes was not returned for analysis, an evaluation and resulting commentary cannot be made on that portion of the lead. Abraded openings were observed on the outer silicone tubing and both of the inner silicone tubes. The quadfilar coils appeared to be stretched, kinked and bare, in some areas. The abraded openings found on the outer silicone tubing and the cut ends that were made during the explanted process, most likely provided the leakage path for the dried remnants of what appeared to have once been body fluids found inside the outer silicone tubing. What appeared to be white deposits were observed in various locations. With the exception of the abraded openings, the condition of the returned lead portions is consistent with those that typically exist following an explant procedure. No other obvious anomalies were noted. The setscrew marks found on the lead connector pin provide evidence that, at one point in time, a good mechanical and electrical connection was present. Continuity checks of the returned lead portions were performed, during the visual analysis, and no discontinuities were identified.
 
Event Description
It was reported that device diagnostics resulted in low impedance (<600 ohms) and that the patient has experienced worsening seizures. The patient was referred for lead replacement. The patient underwent lead replacement on (b)(6) 2015. It was reported that device diagnostics with the new lead and existing generator were within normal limits. The explanted lead has not been received for analysis to date. No additional relevant information has been received to date.
 
Manufacturer Narrative
Device manufacturing records were reviewed. Review of manufacturing records of the lead confirmed all quality tests were passed prior to distribution. Device failure is suspected, but did not cause or contribute to a death or serious injury.
 
Manufacturer Narrative
Device failure occurred, but did not cause or contribute to death or serious injury.

https://www.accessdata.fda.gov/scripts/cdrh/cfdocs/cfmaude/detail.cfm?mdrfoi__id=4531971


Title: Re: Short Circuit
Post by: dennis100 on February 21, 2019, 11:42:38 AM
Model Number MODEL 250
Event Date 03/20/2015
Event Type  Malfunction   
Manufacturer Narrative

Event Description
It was reported that the usb port of the tablet device was damaged and was missing a component. Attempts to perform interrogations resulted in error message stating ¿unable to open port. ¿ the tablet device has been returned to the manufacturer where analysis is currently underway.
 
Event Description
Product analysis was completed for the tablet device on 04/23/2015. The tablet was received without a serial cable. An analysis of the tablet was performed and a visual analysis identified damage to the tablet back cover and usb port. The cause of the damage is unknown, but can be attributed to mishandling of the device. Additionally, functional testing of the tablet identified that it would not power on. The cause for the anomaly is associated with incorrect power and ground wire connections to the wi-fi card. The condition created an electrical short and prevented the tablet from powering on. No further anomalies were identified. Analysis determined that this was definitely not an out of box failure. There was obvious physical damage to the tablet as evidenced by a separated cover and damaged port. This was likely due to the device being dropped. The port was damaged, but still functional, and was used during testing. Even though the port was functional, the damage could definitely have contributed to the ¿unable to open port ¿error which was observed. With the wires reversed, the tablet could not power on. The tablet was also visibly used. There were archived databases present. The tablet would not have functioned at all with the wires connected as it was received. It is likely that after the tablet was dropped, the user incorrectly connected the wires. The company field representative stated that he went to the office to troubleshoot, was able to turn on the tablet and received the ¿unable to open port¿ error. He took the tablet with him that day and it was not dropped. Based on this, it is unclear how the wires became reversed leading to a failure to power on the tablet.

https://www.accessdata.fda.gov/scripts/cdrh/cfdocs/cfmaude/detail.cfm?mdrfoi__id=4685212


Title: Re: Short Circuit
Post by: dennis100 on February 23, 2019, 02:33:04 AM
Model Number 302-20
Event Date 03/03/2015
Event Type  Malfunction   
Event Description
It was reported that the patient was referred for an end of service replacement that took place that day. The patient¿s generator prior to surgery was interrogated and showed ifi-yes. Diagnostics were also taken and resulted in a low impedance of <600 ohms. The patient was doing doing fine and has no increased seizures, so since the ifi=yes flag was seen they decided to replace before it actually gets to eos in case the seizures come back. Patient¿s programming history shows that the impedance has been dropping slowly since implantation suspecting a possible short circuit. The surgeon checked the lead and reported that he did not see anything obvious in terms of abrasions or fluid in lead at the area near the generator. He took out the old generator and replaced with a new generator. He performed the system diagnostics again and got high impedance at 9236 ohms. The surgeon re-inserted the pin and performed diagnostics which again showed a low impedance of <600 ohms. The surgeon performed two more diagnostic results which both showed low impedance but the surgeon decided to not revise the lead since he did not feel comfortable replacing it with just the diagnostic results. Patient was doing well prior to surgery so if there is an issue later on, he will bring them back into surgery. He informed the patient¿s family about his decision also. The explanted generator will not be returned for analysis.
 
Manufacturer Narrative
Device failure is suspected, but did not cause or contribute to a death or serious injury.

https://www.accessdata.fda.gov/scripts/cdrh/cfdocs/cfmaude/detail.cfm?mdrfoi__id=4649309


Title: Re: Short Circuit
Post by: dennis100 on March 02, 2019, 04:09:08 AM
Model Number 302-30
Device Problem Low impedance
Event Date 07/09/2015
Event Type  Malfunction   
Event Description
On (b)(6) 2015 a physician asked whether low impedance in diagnostic testing (60;600) is suggestive of a short circuit. The physician later reported that he does have a patient with low impedance. This low impedance was first observed on (b)(6) 2015 on a system diagnostics test. The physician did not make any changes to the patient's settings at that time. The physician indicated that the patient has an intellectual disability and therefore is unable to express any change in stimulation perception, but that the patient's seizures have been increasing since her last visit in (b)(6). Although surgery is likely, it has not occurred to date.
 
Manufacturer Narrative
Device failure is suspected, but did not cause or contribute to a death.
 
Event Description
On (b)(6) 2015 the patient's generator product information was provided by the implanting facility.
 
Event Description
On (b)(6) 2015 the explanted generator and lead were received for product analysis. Product analysis has been completed on the generator. Various electrical loads were attached to the pulse generator and results of diagnostic tests demonstrate that accurate resistance measurements were obtained in all instances. In the product analysis lab, the device output signal was monitored for more than 24-hrs, while the generator was placed in a simulated body temperature environment. Results showed no signs of variation in the pulse generator's output signal and demonstrated that the device provided the expected level of output current for the entire monitoring period. In addition, a comprehensive automated electrical evaluation showed that the pulse generator performed according to functional specifications; there were no performance or any other type of adverse conditions found with the pulse generator. Product analysis is still underway on the leads and has not yet been completed.
 
Event Description
On (b)(4) 2015 it was reported that the patient underwent a full revision surgery that day. Attempts were made for the return of the explanted products but they have not been received to date.
 
Event Description
Product analysis was completed on the leads on 1/25/2016. The majority of the lead assembly (body) including the electrodes was not returned for analysis; therefore a complete evaluation could not be performed on the entire lead product. During the visual analysis abraded openings were observed on the outer and in one area of the connector ring inner silicone tubing. The quadfilar coil appeared to be stretched and exposed. The abraded openings found on the outer silicone tubing and the cut ends that were made during the explanted process, most likely provided the leakage path for the dried remnants of what appeared to have once been body fluids inside the outer silicone tubing. With the exception of the abraded openings, the condition of the returned lead portions is consistent with those that typically exist following an explant procedure. No other obvious anomalies were noted. The setscrew marks found on the lead connector pin provide evidence that, at one point in time, a good mechanical and electrical connection was present. Continuity checks of the returned lead portions were performed, during the visual analysis, and no discontinuities were identified.
 
Event Description
It was reported that the patient is having an evoked potential test.

https://www.accessdata.fda.gov/scripts/cdrh/cfdocs/cfmaude/detail.cfm?mdrfoi__id=4932439


Title: Re: Short Circuit
Post by: dennis100 on March 04, 2019, 08:00:15 AM
Model Number 303-30
Event Date 07/29/2015
Event Type  Malfunction   
Event Description
It was reported on (b)(6) 2015 that a low impedance warning message was seen on a patient's device upon interrogation. This was the patient's first appointment after battery replacement on (b)(6) 2015. It was noted that after the replacement, diagnostics were taken and came back in range. It was then noted that following a running of the system diagnostics the impedance resulted in range, 1692 ohms. The decoder information from generator was received and indicated that the impedance values were fluctuating from normal impedance values back to low impedance values and then back to normal impedance. Based on these impedance values it is clear that there is a short in the circuit causing the impedance to fluctuate between normal and low readings. This is likely due to wear on the lead based on the age of the device. While surgical intervention is likely, no surgery has been planned or scheduled to date.

https://www.accessdata.fda.gov/scripts/cdrh/cfdocs/cfmaude/detail.cfm?mdrfoi__id=5048038


Title: Re: Short Circuit
Post by: dennis100 on March 05, 2019, 07:33:02 AM
Model Number 304-20
Device Problems Fracture; Device Displays Incorrect Message ; Lead
Event Date 07/23/2015
Event Type  Malfunction   
Manufacturer Narrative

Event Description
Analysis of the explanted generator and lead was completed. Analysis of the lead confirmed openings of both the outer and inner silicon tubing in adjacent areas, exposing conductive quadfilar coils and creating a potential short-circuit condition. Analysis of the generator revealed no anomalies. Various electrical loads were attached to the pulse generator and results of diagnostic tests demonstrate that accurate resistance measurements were obtained in all instances. A comprehensive automated electrical evaluation showed that the pulse generator performed according to functional specifications. There were no performance or any other type of adverse conditions found with the pulse generator. The downloaded data from the generator revealed that low impedance was observed (change from 207 ohms to 379 ohms on (b)(6) 2015).
 
Event Description
The explanted generator and lead have been received by the manufacturer for analysis. However, analysis has not been completed to date.
 
Event Description
It was reported that the patient presented to the er with increased seizures below pre-vns baseline. Upon diagnostics while in the er, low impedance was noted. It was stated that the low impedance message appeared indicating the impedance value was less than 600 ohms. The device was thus disabled. Review of the manufacturer's available programming history for this patient revealed that diagnostics on date of implant, (b)(6) 2011, revealed normal impedance values. It was reported that the patient had a status epilepticus event one night while the device was disabled, prior to the date of surgery. The patient underwent generator and lead replacement surgery on (b)(6) 2015 due to prophylactic generator replacement and low impedance. Diagnostics prior to surgery again revealed low impedance. It was also reported that a lead fracture was visually observed during the surgery. The explanted generator and lead have not be received by the manufacturer for analysis to date.

https://www.accessdata.fda.gov/scripts/cdrh/cfdocs/cfmaude/detail.cfm?mdrfoi__id=5009042


Title: Re: Short Circuit
Post by: dennis100 on March 17, 2019, 02:40:40 AM
Model Number 302-30
Device Problems Low impedance; Device Displays Incorrect Message
Event Date 11/06/2015
Event Type  Malfunction   
Event Description
It was reported by the physician that the patient no longer feels stimulation. It was also reported the physician received the low impedance <600 ohms warning when interrogating the device. The patient was referred to a consultation for a full revision and replacement of the vns system. It was also reported the patient is severely mentally retarded and developmentally delayed. The patient is also prone to violent outbursts.
 
Event Description
It was reported the patient is a poor historian and the date of initial onset for the inability of the patient to perceive stimulation is not known. Additionally, it was reported there was no known trauma or incident suspected that could have caused or contributed to the reported event. No additional relevant information has been received to date.
 
Event Description
It was reported the patient underwent lead and generator revision surgery on (b)(6) 2016. Pre-operative testing of the vns verified the low impedance previously observed. The physician put a new generator on the existing lead and found 615 ohms. The decision was made to removed and replace the lead. It was found during surgery the electrodes were not on the nerve and there was no strain relief loop or anchor tethers present. The new lead was placed on the nerve, tethered and connected to the new generator. Diagnostics were performed and showed 2155 ohms. There was no known trauma or manipulation that could have caused the lead to come off of the nerve; however, the patient is autistic and combative. No additional relevant information has been received to date.
 
Event Description
Product analysis for the returned generator was completed. The generator output signal was monitored for more than 24 hours while in a simulated body temperature environment. Results showed no signs of variation in the generator's output signal and demonstrated the device provided the expected level of output current for the entire monitoring period. In addition, a comprehensive automated electrical evaluation showed the generator performed according to functional specifications. The battery voltage measured during analysis showed an ifi = yes (intensified follow-up indicator) condition. There were no performance or any other type of adverse conditions found with the generator.
 
Event Description
Pa for the returned lead portion was approved on (b)(6) 2016. The lead was found to have abraded openings on the outer and inner silicone tubing of the lead coils. Also, the positive and negative lead coils have what appear to be wear (flat surfaces) at the exposed portions located past the electrode bifurcation. The reported ¿low impedance¿ allegation was not verified. Though it was difficult to state conclusively, the identified exposed coil portions at the silicone tubing abraded openings may confirm this to be a contributing factor for the reported low impedance/short circuit condition. However, the exact point in time when the short occurred is unknown. Note that since the electrode array portion was not returned for analysis, an evaluation and resulting commentary cannot be made on that portion of the lead. Other than the above mentioned observations and typical wear and explant related observations, no other anomalies were identified in the returned lead portion.
 
Event Description
It was also observed, during lead product analysis, that the lead connector boot had partial detachment at the ring/backfill interface. The reason for this condition was unknown.
 
Manufacturer Narrative
Describe event or problem; corrected data: this information was inadvertently left off of the supplemental #04 mfr. Report.
 
Event Description
The lead assembly had dried remnant of what appeared to have once been body fluids inside the inner and the outer silicone tubing. No obvious point of entrance was noted other than the identified tubing openings and the end of the returned lead portion.

https://www.accessdata.fda.gov/scripts/cdrh/cfdocs/cfmaude/detail.cfm?mdrfoi__id=5257603


Title: Re: Short Circuit
Post by: dennis100 on March 24, 2019, 01:16:02 AM
Model Number 302-20
Device Problems Insulation; Hole In Material; Low impedance; Scratched Material
Event Date 12/10/2006
Event Type  Malfunction   
Event Description
Information was received indicating that low lead impedance was repeatedly observed via system diagnostics with a new pulse generator and a prior implanted lead during a generator replacement surgery. The surgeon verbally reported that the lead looked odd. It is unknown if generator diagnostics were performed with a test resister to test the generator's ability to accurately measure impedance. The physician did not replace the lead and the patient is being referred for a revision surgery. Subsequently received operative notes indicate that the physician observed a significant gap (opening) in the silicone insulation of the lead and attributed the low impedance to this condition. Pictures were taken of the lead and submitted and show possible, but inconclusive, insulation abrasion. A review of programming history with the prior device indicates system diagnostics lead impedances ranging from 0 to 2 with a decrease from 2 to 0 for the last several years of the available date. System diagnostic data from the date of replacement surgery with the prior pulse generator indicates dcdc 0, a warning of low lead impedance and impedance value <600 ohms. Attempts for additional relevant information have been unsuccessful to date and no known surgical interventions have occurred to date.
 
Event Description
The patient underwent lead explant and replacement on (b)(6) 2015. The surgeon left the electrode portion of the lead implanted and the new lead electrodes were placed above the former electrodes. It was observed that the lead insulation was broken down. No pre-operative device check was performed. The explanted lead has not been received by the manufacturer to date.
 
Event Description
The explanted lead was returned to the manufacturer. Product analysis confirmed abraded openings of the outer and inner silicone tubes in adjacent areas, exposing the conductive quadfilar coils and creating a potential short-circuit condition. A break of the positive coil in the electrode region of the returned lead was also observed. It is unknown if the break occurred while stimulation was present due to the absence of metal pitting on the broken coil wire surfaces. With the exception of the discontinuity and abraded openings, the condition of the returned lead portions is consistent with those that typically exist following an explant procedure. No other obvious anomalies were noted. Note that since a portion of the lead assembly (body), including the electrode array section was not returned for analysis, an evaluation and resulting commentary cannot be made on that portion of the lead.
 
Manufacturer Narrative
(b)(4).

https://www.accessdata.fda.gov/scripts/cdrh/cfdocs/cfmaude/detail.cfm?mdrfoi__id=5275057


Title: Re: Short Circuit
Post by: dennis100 on March 29, 2019, 07:50:40 AM
Model Number 304-20
Event Date 01/01/2016
Event Type  Malfunction   
Event Description
During a prophylactic generator replacement (ifi = yes) on (b)(6) 2016, the surgeon accidentally cut the lead and had to perform lead revision. The explanted generator and lead were received. An analysis was performed on the returned lead portions. The reported allegations of lead fracture due to surgeon accidentally cutting the lead was confirmed based on the condition of the returned lead portions. During the visual analysis of the returned lead, abraded openings were observed on the connector pin and connector ring inner silicone tubes. Pitting was observed on the connector ring quadfilar coil surface, in this area. Analysis confirmed opening of both inner tubing sections in adjacent areas, exposing conductive quadfilar coils and resulting in coil pitting and a potential short-circuit condition. With the exception of the slice marks, puncture marks and abraded inner tubing openings, the condition of the returned lead portions is consistent with those that typically exist following an explant procedure. The abraded openings of both inner tubes is suspected to have occurred during the implant life and prior to explant surgery. The setscrew marks found on the lead connector pin provide evidence that, at one point in time, a good mechanical and electrical connection was present. Continuity checks of the returned lead portions were performed, during the visual analysis, and no discontinuities were identified. Based on the findings, there is no evidence to suggest discontinuities in the returned portions of the device which may have contributed to the stated allegations of high impedance/lead fractures. A comprehensive automated electrical evaluation showed that the pulse generator performed according to functional specifications. The battery, 2. 914 volts, shows an ifi=no condition. Various electrical loads were attached to the pulse generator and results of diagnostic tests demonstrate that accurate resistance measurements were obtained in all instances. There were no performance or any other type of adverse conditions found with the pulse generator.

https://www.accessdata.fda.gov/scripts/cdrh/cfdocs/cfmaude/detail.cfm?mdrfoi__id=5542841


Title: Re: Short Circuit
Post by: dennis100 on April 02, 2019, 12:21:51 AM
Model Number 304-20
Device Problems Fracture; High impedance; Low impedance
Event Date 04/17/2016
Event Type  Malfunction   
Manufacturer Narrative
(b)(4).
 
Event Description
A physician reported to an international distributor that low lead impedance had been observed in a patient's vns system at a device follow-up. X-rays were taken and provided to the manufacturer for review. The x-rays showed no obvious anomalies but did reveal a possible sharp bend in the lead just above the generator and a possible pin insertion issue. The entire lead body could not be evaluated based on the x-ray images submitted. Submitted diagnostic data shows three low impedance (<600 ohms) measurements on (b)(6) 2016 along with 7 normal impedance measurements on that same date. A decrease in impedance is observed in the data over the last seven months. No patient adverse events have been reported. The physician intends to monitor the patient's condition and continue normal patient following. No specific intervention is planned and no surgical interventions have occurred to date.
 
Event Description
Follow-up on this event was provided indicating that the patient's impedance values were fluctuating. The patient had low impedance values that fluctuated to high impedance on (b)(6) 2016. Then, on (b)(6) 2016 the impedance values were all within normal limits. Then, the patient was visited on (b)(6) 2016 and the impedance values were high on multiple system diagnostic tests. The system diagnostic test on (b)(6) 2016 was also high. Then, the patient was seen on (b)(6) 2017 and the impedance was within normal limits. A new set of x-rays was provided for review and there was no indication of a sharp angle on this x-ray and the lead pin did not appear fully inserted into the connector block. No know surgical intervention has occurred to date.
 
Event Description
The patient was seen for a clinic visit on (b)(6) 2018, and high lead impedance was observed on her device. The distributor noted that the patient's device had previously shown both high and low lead impedance, but the impedance values had recently been within the normal range. Diagnostics performed at the clinic visit indicated an output current of only 0. 50 ma was being delivered, although the generator was programmed to 1. 5 ma. The distributor planned to send x-rays to the manufacturer for review. The x-rays were received by the manufacturer but have not been reviewed to date. The full programming history was reviewed for the patient's generator. Fluctuating impedance values were observed throughout a significant portion of the programming history, including the aforementioned low and high impedance, along with several internal impedance changes not observed in previous diagnostic tests. Low impedance was internally detected between multiple interrogations when impedance appeared to be normal in system diagnostic testing, indicating several quick fluctuations in impedance value. On (b)(6) 2017 impedance values were within the normal limits and remained so through multiple clinic visits until (b)(6) 2018; however, the high impedance was internally detected three days prior. No additional relevant information has been received to date. No surgical intervention has occurred to date.
 
Event Description
The x-ray images were reviewed by the manufacturer. Due to the angle of the generator in the image, lead pin insertion into the generator could not be assessed. The filter feedthrough wires appeared intact, and the lead wire appeared intact at the lead pins. The lead was observed in the neck and chest. Due to the exclusion of the patient¿s upper neck from the provided images, the presence of strain relief could not be assessed in its entirety; however, a strain relief bend did appear to be present, and a strain relief loop appeared to be complete. Two tie-downs secured the lead at the strain relief bend, and one tie-down secured the lead at the strain relief loop. A portion of the lead appeared to be routed behind the generator. No gross fractures or lead discontinuities were observed in the provided images as visibility of the lead was lost near the collarbone. 3d-ct images were also included with the provided x-ray images. The presence and completeness of the lead strain relief was confirmed in the 3d-ct images. The portion of the lead routed behind the generator was also visible in the images, and a gross fracture was visualized in the portion of the lead that was not visible in the x-ray image. The thickness of the lead was minimal at the fracture location compared to the remainder of the lead body, signaling the potential for a short circuit condition to have existed. No additional relevant information has been received to date. No surgical intervention has occurred to date.

https://www.accessdata.fda.gov/scripts/cdrh/cfdocs/cfmaude/detail.cfm?mdrfoi__id=5672042


Title: Re: Short Circuit
Post by: dennis100 on April 08, 2019, 02:18:31 AM
Model Number 304-20
Device Problem Low impedance
Event Date 08/30/2017
Event Type  Malfunction   
Event Description
It was found in programming history that there was evidence of fluctuating lead impedance levels, indicating a short circuit or low impedance condition. No additional information has been received.

https://www.accessdata.fda.gov/scripts/cdrh/cfdocs/cfmaude/detail.cfm?mdrfoi__id=8392232


Title: Re: Short Circuit
Post by: dennis100 on April 13, 2019, 03:59:48 AM
Model Number 304-20
Event Date 06/30/2015
Event Type  Malfunction   
Manufacturer Narrative

Event Description
During review of the in-house programming/diagnostic history database, it was observed that low impedance was observed at office visit on (b)(6) 2015. A subsequent diagnostic test was performed during the same visit and resulted with normal impedance levels. It is unknown if any patient manipulation or trauma occurred that could have caused or contributed to the low impedance reading. Review of the programming data that captured the low impedance found that when the low impedance message presented the actual impedance value was measured as 384 ohms. Further follow-up found that the generator was still presenting with a low impedance message during a visit on (b)(6) 2016. No surgical interventions are known to have occurred to date.
 
Event Description
It was reported that the patient was experiencing a funny sensation in the neck and throat; which was attributed to vns stimulation. This change in perception was noted at the same time that the low impedance was observed and therefore appears to be related. The patient was referred for a lead and generator replacement however no surgical interventions are known to have occurred to date.
 
Event Description
The patient underwent vns lead and generator replacement surgery. In pre-op, diagnostic testing resulted within normal limits. During surgery the surgeon observed approximately 1 inch of the lead insulation was stripped off of the lead. The missing piece of the lead insulation could not be located. The lead and generator were then explanted and later received by the manufacturer. Both products are currently pending product analysis.
 
Event Description
Product analysis on the generator was completed. During analysis the output signal of the generator was monitored for more than 24-hrs and no variations in the output signal or expected level of output current were observed. The generator performed to functional specification.
 
Event Description
Product analysis was completed on the received lead portions. It was noted that the portion of the lead with the electrodes was not received therefore a complete evaluation could not be performed on the entire lead. The lead was received in 4 portions with the segment containing the lead connector pin still inserted into the generator. A continuity measurement verified electrical and mechanical contact between the generator and the lead pin. X-rays were taken and revealed that the canted spring of the generator was making contact with the connector ring of the lead. The continuity of the lead portions were evaluated and no discontinuities were identified within each portion. During analysis it was observed that the outer and inner silicone tubing had abrasions which would have made it possible for the quadfilar coils to come in contact with each other which would have caused a short circuit condition that would result in low impedance. Bodily fluids were observed inside the inner and outer tubing and coil fractures were observed in multiple areas however pitting was not observed. Analysis determined that the mechanism for some of the fractures appeared to be stress induced. However the mechanism for all of the fractures could not be determined. Based on the results of analysis it appears that the cause of the low impedance is related to a short circuit condition in the lead.
 
Event Description
It was reported that the patient experienced discomfort when the lead and generator were implanted.

https://www.accessdata.fda.gov/scripts/cdrh/cfdocs/cfmaude/detail.cfm?mdrfoi__id=5896715


Title: Re: Short Circuit
Post by: dennis100 on May 11, 2019, 01:08:27 AM
Model Number 304-20
Device Problem Fracture
Event Date 03/12/2019
Event Type  Malfunction   
Event Description
The patient's neurologist had reported that they believed that the there was a lead issue as the impedance was around 800 ohms. It was explained to the neurologist that while the impedance is within normal limits, a representative would attend the surgery. While in surgery, the surgeon was able to see that the lead was exposed and the silicone cover was damaged, and the procedure was updated from a prophylactic generator replacement to a full revision. It was stated that there was a short circuit condition. The patient's lead and generator were replaced. The devices were not returned to livanova to date. No additional or relevant information has been received to date.

https://www.accessdata.fda.gov/scripts/cdrh/cfdocs/cfmaude/detail.cfm?mdrfoi__id=8470989


Title: Re: Short Circuit
Post by: dennis100 on May 14, 2019, 12:23:17 AM
Model Number 302-20
Device Problem Low impedance
Event Date 03/17/2010
Event Type  Malfunction   
Event Description
It was initially reported from social media post that a patient¿s son did not see any benefit from the vns device. At this point patient information was unknown. Additional information was received from the patient¿s mother which identified the patient whose vns was said to be ineffective. She said that the generator was dead and that vns had "failed" and did not help her son enough to agree to have the generator replaced. She said that the patient's physician had told her that explant would run the risk of infection and that it would be safer to keep the system implanted. The programming history database was reviewed and showed a possible short circuit condition. It appears that there was a dramatic drop in impedance from (b)(6) 2009 dcdc 2 to (b)(6) 2010 showing dcdc 0. Along with the allegation that the device was ineffective, this shows there may have been a short circuit condition present. No additional information has been received to date.

https://www.accessdata.fda.gov/scripts/cdrh/cfdocs/cfmaude/detail.cfm?mdrfoi__id=8491506


Title: Re: Short Circuit
Post by: dennis100 on May 20, 2019, 09:02:43 PM
Model Number 304-20
Device Problems Corroded ; Fracture; Mechanical Problem; Low impedance
Event Date 04/11/2017
Event Type  Malfunction   
Event Description
It was reported that during an office visit a diagnostic test was performed and resulted in low impedance. It was also reported that the patient had been experiencing an increase in seizures and a change in behavior which both appeared to be related to the low impedance. X-rays were performed and reviewed by the manufacturer. However due to the poor quality of the images provided the integrity of the lead was difficult to assess. Therefore the cause of the low impedance could not be determined. The patient was then referred for surgery where the lead and generator were replaced. The explanted products have not been received to date.
 
Event Description
The generator and lead were received by the manufacturer. The generator product analysis was completed. Visual analysis noted signs consistent with generator manipulation during explantation. The device was noted to be at ifi = no. The results were expected for all diagnostic tests in which various impedance loads were applied to the generator. The output signal of the generator was monitored for a 24 hour period and there were no variations in the output. The device performed to specification. The lead is pending product analysis.
 
Event Description
Analysis was completed on the lead. The lead was received in two portions of tubing with 3 loose quadfilar coils. Set screw marks confirmed that at one time there was adequate connection between the lead pin and generator. Visual analysis observed several abraded openings in the inner & outer tubing that appeared to be caused by wear. These confirmed openings were in adjacent areas and the exposed conductive quadfilar coils created a potential short-circuit condition thus confirming the report of low impedance. Additionally, lead fractures were observed in various locations. Some fractures appeared to be caused by the explant procedure while others appeared to have been caused by mechanical fatigue. Pitting was observed at some fracture sites, indicating that the stimulation was still be provided after the fracture occurred. It was noted that the three loose strands of coil each had melted ends indicating they were exposed to electrocautery during the explant procedure.

https://www.accessdata.fda.gov/scripts/cdrh/cfdocs/cfmaude/detail.cfm?mdrfoi__id=6563365


Title: Re: Short Circuit
Post by: dennis100 on June 09, 2019, 12:51:43 AM
Model Number 302
Device Problems Corroded ; Fluid Leak; Fracture; Low impedance
Event Date 01/31/2016
Event Type  Malfunction   
Event Description
It was reported that the physician performed a diagnostic test during a visit and observed a low impedance warning. Chest x-rays were reviewed by the physician and a lead fracture was observed. These images have not been reviewed by the manufacturer to date. It is unknown if the patient sustained an injury which could have caused the lead fracture. The device was programmed off and the patient was referred for surgery. No surgical interventions are known to have occurred to date.
 
Event Description
It was reported that the patient underwent lead and generator replacement surgery. The explanted products have not been received to date.
 
Event Description
The explanted lead and generator were received. Both are currently pending analysis.
 
Event Description
Analysis was completed on the returned generator and lead. During testing the generator performed to functional specification and no anomalies were observed. The internal data of the generator was reviewed and confirmed that a low impedance had occurred while implanted. The lead was received in 5 segments which included the lead pin and electrodes. There were set screw marks on the pin which indicated that there was good contact between the lead and generator at one time. Abrading openings were found in the inner and outer tubing in various locations in the lead. Scanning electron microscopy was used to evaluate the lead and found broken coil strands with evidence that the fracture was stress induced from fatigue and rotational forces. There was evidence of pitting on one coil strand which indicates that the fracture was present while stimulation was occurring. Additionally with the abraded insulation, it was found that a short condition was occurring between the coils. Analysis of the lead confirmed the short circuit condition which caused the low impedance.

https://www.accessdata.fda.gov/scripts/cdrh/cfdocs/cfmaude/detail.cfm?mdrfoi__id=6852981


Title: Re: Short Circuit
Post by: dennis100 on June 18, 2019, 12:25:50 AM
Model Number 304-20
Device Problems Corroded ; Fracture; Low impedance
Event Date 11/21/2017
Event Type  Malfunction   
Manufacturer Narrative
 
Event Description
Low impedance was observed on a patient's device during a clinic visit. Three weeks earlier, impedance values near the bottom of the normal range had been observed on the patient's device. The impedance was otherwise normal throughout the remainder of the available programming history. The patient was scheduled for revision surgery due to the low impedance. X-rays images of the patient's lead and generator were reviewed by the manufacturer. The lead appeared wavy in several portions. A portion of the lead was not visible in the x-ray images, indicating the likelihood of a larger lead break. A sharp angle was observed at the center of three tie-downs used to secure the top of the lead, indicating the presence of a lead discontinuity or short circuit condition. The patient underwent lead and generator replacement surgery. The lead had reportedly become disconnected inside the patient. The physician reported that the patient did not manipulate the device or experience any trauma that may have led to the low impedance or broken lead. The explanted devices have not been received by the manufacturer to date. No additional relevant information has been received to date.
 
Event Description
The distributor and physician believed that low lead impedance was observed on the generator because the lead was short-circuited at the lead break. The explanted lead and generator were received by the manufacturer for analysis, but analysis has not been approved for the explanted devices to date.
 
Manufacturer Narrative
(b)(4).
 
Event Description
Analysis was approved for the lead and generator. When received, the data was downloaded from the pulse generator and reviewed. The last significant change in impedance value registered on the generator was observed the day before explant surgery. And both impedance values were below 1000 ohms. The pulse generator performed according to functional specifications. There were no performance or any other type of adverse conditions found with the pulse generator. The lead was returned in two portions. Note that since the electrode array portion was not returned for analysis, an evaluation and resulting commentary could not be made on that portion of the lead. Set screw marks were observed on the connector pin, providing evidence that proper contact existed between the lead and generator at least once. Microscopy identified a stress-induced fracture at the lead break location, and secondary stress-induced fissures were also noted in two strands of the positive coil. A portion of the positive coil is exposed and stretched at a lead break location. An intermittent contact was identified between the lead coils. Pitting and wear were identified near the break location on the negative and positive coils. Abraded openings were identified along the outer and inner tubing of the lead and were points of entry for dried fluid observed in both layers of tubing. The appearance of the lead suggested patient manipulation of the implanted device. Identification of portions of the lead coils being exposed may confirm this to be a contributing factor for the reported low lead impedance. Other than the above mentioned observations and typical wear and explant related observations, no other anomalies were identified in the returned lead portion.

https://www.accessdata.fda.gov/scripts/cdrh/cfdocs/cfmaude/detail.cfm?mdrfoi__id=7123169


Title: Re: Short Circuit
Post by: dennis100 on August 09, 2019, 10:00:48 PM
Model Number 304-20
Device Problem Low impedance
Event Date 06/27/2019
Event Type  Malfunction   
Event Description
It was reported that a patient's device has low impedance and that there are no complaints from the patient. Anteroposterior and lateral chest x-rays were received and reviewed. Per the images received, the connector pin insertion cannot be assessed due to the quality and angle of the image. The placement of the generator is normal. The feed thru wires do not seem intact at the connector pin and appeared bent. The lead was located behind the generator and the lead wires at the connector pins could not be assessed due to the quality and angle of the image. The lead was observed in the patient¿s neck and appeared to be routed toward the patient¿s left chest. There is no strain relief loop or bend present. One tie-down was visualized and not placed per labeling - tie down and lead were not located parallel to the electrodes. No gross fractures were visualized however a sharp angle was seen, directly below the electrodes, and appears to be looped over itself. Based on the x-rays received, the cause of the low impedance cannot be determined, as no obvious short circuit condition could be visualized. The sharp angle below the electrode and the bent feed through wires cannot be ruled out as possible causes, however, cannot be confirmed to be reasons for the low impedance. A possible fracture or short circuit in the part of the lead that was not able to be visualized in the x-ray images and also cannot be ruled out. No surgical intervention has been reported to date. No additional relevant information has been received to date.

https://www.accessdata.fda.gov/scripts/cdrh/cfdocs/cfmaude/detail.cfm?mdrfoi__id=8798633