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dennis100
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« on: May 11, 2011, 11:08:56 AM »

Event Date 09/11/2000
Event Type Injury
Patient Outcome Hospitalization; Required Intervention
Event Description
Reporter indicated that device was explanted due to infection and protrusion through skin. In 2000 wound opened up due to infection and generator was explanted. In 2001, lead began protruding through incision and was explanted (electrodes left on nerve). About 8 weeks later patient presented with red and granulated tissue around the neck area. Physician noticed a small piece of wire sticking up through the skin. During surgery to remove remainder of lead, physician reported that what was remaining of the lead and electrodes was floating in the neck. Physician reported that the electrode had slipped off the nerve and had started comming through the skin.

http://www.accessdata.fda.gov/scripts/cdrh/cfdocs/cfmaude/detail.cfm?mdrfoi__id=326155
« Last Edit: September 25, 2015, 06:10:37 AM by dennis100 » Logged
dennis100
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« Reply #1 on: May 11, 2011, 11:10:13 AM »

Model Number 300-20
Event Date 12/03/2001
Event Type Malfunction
Event Description
Reporter indicated that at a follow up visit during the week in 2002, the patient's physician ordered x-rays to check the connection of the lead since the patient does not display any side effects of stimulation and has reported continued lack of benefit from the vns implant. It was reported that the x-ray suggests that one part of the connection to the nerve is "disconnected" but that the x-ray was inconclusive. The physician increased the programmed parameters and as the device was tested with the magnet the patient went into a seizure during magnet mode stimulation. It was reported that the patient continues to have seizures in which their left side completely goes numb, rendering the patient helpless and severely limiting the patient and the patient's parents' activities. It was reported that this is a relatively new phenomena (past year) and that the patient has had two or three bad episodes of this since the stimulator was activated (12/2001). It was reported that the physician planned only to observe the patient over the next three months. It is suspected that user error may have caused or contributed to a lead discontinuity, improper lead placement on the nerve, or improper lead connection to the generator, resulting in lack of therapy for the patient.

Manufacturer Narrative
Reporter indicated that during the revision surgery on 3/27/2002 it was verified that the lead was nowhere near the nerve. It was also reported that no tie downs were used in the initial implant. The neurosurgeon was going to reattach the lead to the nerve but during the surgery he noticed that the lead was damaged. The initial lead was explanted and a new lead was re-implanted. Lead test at re-implant surgery resulted in an ok impedance.

Manufacturer Narrative
Physician indicated that the pt's lead was not placed correctly on the nerves. Pt's parent reported that the pt is scheduled to have revisional surgery performed on his neck to properly connect the wire to the nerve on 3/27/02.

Manufacturer Narrative
Device programming history was reviewed. X-rays were reviewed. Manufacturing records were reviewed. Review of device programming history did not reveal any anomalies or abnormalities. X-ray review revealed that the electrodes and adjacent lead appear to be in a non-recommended routing. No tie-downs are present. The electrodes do not appear to be properly aligned (not parallel). The lead appears to be fully intact; however, the electrodes appear to be low on the nerve if on the nerve at all. Review of manufacturing records did not reveal any anomalies or abnormalities that would have an adverse effect on device performance.

http://www.accessdata.fda.gov/scripts/cdrh/cfdocs/cfmaude/detail.cfm?mdrfoi__id=379476
« Last Edit: November 10, 2015, 04:05:25 AM by dennis100 » Logged
dennis100
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« Reply #2 on: May 11, 2011, 11:10:47 AM »

Event Date 07/01/2002
Event Type Malfunction
Event Description
Reporter indicated that device diagnostic testing at office visit in 07/02 resulted in high lead impedance reading (dc-dc code 7 and limit), indicating possible device malfunction. The patient underwent generator replacement surgery in 2002 due to end of service. Device diagnostic testing in 06/2002 resulted in high lead impedance reading (dc-dc code 4, ok and high), indicating that the ncp system was functioning properly, but that the generator was working harder to deliver the programmed therapy. X-rays did not reveal any obvious discontinuities in the ncp system, but it did appear that the negative electrode may not be properly attached to the nerve. Further follow-up revealed that the lead was replaced in 2002. The patient reportedly had an excessive amount of scar tissue around the lead coils on the nerve. The physician indicated that the excess scar tissue may have contributed to the high lead impedance readings by preventing a good connection of the lead to the nerve. In addition, the nurse reported that they believed that the patient was still feeling stimulation prior to lead replacement surgery because the patient would grab at their neck. It was also reported that the patient was not as alert and was hallucinating before lead replacement surgery because of heavy medication changes. The patient stated that they were not aware of any injury that they may have experienced that could have caused damage to the ncp system. The patient has reportedly had fewer seizures with the vns implant.

http://www.accessdata.fda.gov/scripts/cdrh/cfdocs/cfmaude/detail.cfm?mdrfoi__id=412996

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dennis100
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« Reply #3 on: May 11, 2011, 11:11:21 AM »

Event Date 01/01/2001
Event Type Injury
Patient Outcome Life Threatening; Hospitalization Required Intervention
Event Description
Reporter indicated that the patient developed an infection and the ncp system was replaced. The original electrodes were left in place on the nerve. The patient developed cyst-like lumps over the incision sites and the second ncp system was removed. Reporter indicated that the patient has gone through 10 surgeries to resolve the infection. Reporter indicated that in december 2001, the patient developed another lump in the scar on their neck which made the scar open, exposing the coil from the nerve. It was reported that the patient's family member pulled the coil out with their fingernails. An attempt to obtain additional information was made. No response to date.

http://www.accessdata.fda.gov/scripts/cdrh/cfdocs/cfmaude/detail.cfm?mdrfoi__id=406405
« Last Edit: September 25, 2015, 06:11:00 AM by dennis100 » Logged
dennis100
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« Reply #4 on: May 11, 2011, 11:12:15 AM »

Event Date 05/25/2001
Event Type Malfunction
Manufacturer Narrative
Review of x-ray was unable to determine whether the electrodes were properly placed on the vagus nerve. No tie-downs were evident on the x-ray film. Revision surgery is scheduled for 2001.

Event Description
Reporter indicated that it was believed that the electrode may have slipped off of the nerve because the pt was having pain in neck.

http://www.accessdata.fda.gov/scripts/cdrh/cfdocs/cfmaude/detail.cfm?mdrfoi__id=339415
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dennis100
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« Reply #5 on: May 11, 2011, 11:12:48 AM »

Event Date 02/01/2003
Event Type Malfunction
Event Description
Reporter indicated that for the past couple of weeks, the patient has had an increase in seizure activity. Device diagnostic testing at office visit in 2003 resulted in high lead impedance reading (dc-dc code 7 and limit), indicating possible device malfunction. The elective replacement indicator was no, indicating that the generator was not at end of service. X-rays reviewed by physician did not reveal any obvious discontinuities in the ncp system. Exploratory surgery was performed the following month at which time the patient's original lead was connected to a new generator. Device diagnostic testing repeatedly resulted in high lead impedance readings, indicating a potential break in the patient's original lead. The patient's ncp system (both lead and generator) was replaced. The patient indicated to neurosurgeon's nurse that the original lead electrodes had come off of the nerve, causing the high impedance readings; however, investigation to date has been unable to confirm.

http://www.accessdata.fda.gov/scripts/cdrh/cfdocs/cfmaude/detail.cfm?mdrfoi__id=452602
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dennis100
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« Reply #6 on: May 11, 2011, 12:06:25 PM »

Event Date 05/22/2003
Event Type Other Patient Outcome Other;
Event Description
Pt undergoing removal of a vagal nerve stimulator implant that was placed in 2003. The surgeon was removing it due to an infection. He couldn't remove all of it since the lead was wrapped around carotid and vagal nerves. The device did not malfunction.

Event Description
Add'l info rec'd from mfr 7/31/03: cyberonics reported this event to the fda on 06/20/2003 (reference 1644487-2003-00345). Further follow-up revealed that the infection was present at both the pulse generator pocket and the lead cervical incision sites. Swab cultures were performed in 2003 at the pulse generator pocket area and resulted in staph aureus. The pulse generator was explanted and the lead was cut, leaving the electrodes attached to the vagus nerve. The infection was treated with antibiotics. A re-implant is planned; however, it has not been scheduled. The physician indicated that the infection has been resolved. Additionally, it was reported that the pt had surgery on their left shoulder within three months of having the vns implant. The voluntary medwatch form (mw1028672) indicates that the lead was wrapped around carotid and vagal nerves. This is incorrect. Cyberonics obtained the operative notes from the explant. The operative notes do not state that the lead was wrapped around the carotid nerve. The surgeon stated ". It was so heavily infested with scar tissue there was no way to see any of the plane between the vagus and the carotid" due to this, the surgeon elected to cut the lead and leave the electrodes on the vagus nerve rather than risk damaging the vagal nerve or carotid artery. The expiration date on the initial mdr was incorrectly entered. The expiration date is 09/30/2004 and the device was implanted prior to this date. This correction was included in an mdr supplement submitted to the fda on 07/22/2003. The manufacturing records were reviewed for both the pulse generator and the lead. Sterilization was confirmed. Cyberonics does not believe that the infection was attributable to the devices. Cyberonics believes that the infection was attributable to the implant surgery.

http://www.accessdata.fda.gov/scripts/cdrh/cfdocs/cfmaude/detail.cfm?mdrfoi__id=465978


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dennis100
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« Reply #7 on: May 11, 2011, 11:23:38 PM »

Event Type Malfunction
Event Description
Reporter indicated that device diagnostic testing resulted in high lead impedance reading (dc-dc code 7 and limit), indicating possible device malfunction. The patient had reportedly undergone generator replacement surgery for end of service approximately one year prior. Shortly after generator replacement surgery, the original lead came off of the nerve. Revision surgery was performed and the lead was reconnected to the nerve. Approximately one year later, device diagnostic testing resulted in high lead impedance reading. The elective replacement indicator was no, indicating that the generator was not at end of service. Lead break or disconnect is suspected. Revision surgery is planned.

http://www.accessdata.fda.gov/scripts/cdrh/cfdocs/cfmaude/detail.cfm?mdrfoi__id=479190

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dennis100
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« Reply #8 on: May 12, 2011, 12:33:58 AM »

Event Date 01/01/2003
Event Type Malfunction
Event Description
Reporter indicated that device diagnostic testing at office visit resulted in high lead impedance reading (dc-dc code 7), indicating possible device malfunction. The patient reportedly felt the device was not working at times and occasionally did not feel stimulation. The patient had not suffered any injury or trauma that may have damaged the vns therapy system. Further follow-up revealed that the patient underwent revision surgery during which the lead was noted to be disconnected from the generator. Generator malfunction was ruled-out as pre-implant test on the device was within normal limits. The lead connector pins were cleaned and reconnected to the generator, after which device diagnostic testing again resulted in high lead impedance reading. The surgeon then opened the neck incision and noted excessive amounts of scar tissue. After 3 hours of dissecting through the scar tissue, the surgeon had not still been able to locate the vagus nerve. Both the lead and generator were explanted and the patient was not reimplanted.

http://www.accessdata.fda.gov/scripts/cdrh/cfdocs/cfmaude/detail.cfm?mdrfoi__id=470181

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dennis100
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« Reply #9 on: May 12, 2011, 07:49:54 AM »

Event Date 01/01/2003
Event Type Malfunction
Event Description
Reporter indicated that the lead electrodes had come completely off of the pt's nerve. The pt had experienced nearly 100% efficacy with the vns therapy, but treating neurologist ordered x-rays due to a recent seizure. Upon review of the x-rays, it appeared that there was no strain relief loop present in the lead wires. Revision surgery was performed during which it was noted that the lead electrodes were completely off of the nerve. The lead was replaced and the explanted lead was discarded. It was reported that the pt manipulates the generator through the skin. Treating neurologist believed that this was the cause of the lead being off of the nerve and that there was no malfunction or anomaly with the lead itself.

http://www.accessdata.fda.gov/scripts/cdrh/cfdocs/cfmaude/detail.cfm?mdrfoi__id=512136

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dennis100
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« Reply #10 on: May 13, 2011, 01:31:51 AM »

Event Date 01/01/2004
Event Type Malfunction
Event Description
Device diagnostic testing at office visit resulted in high lead impedance reading (dc-dc code 7 and limit), indicating possible device malfunction. The elective replacement indicator was no, indicating that the generator had not reached end of service. Pt was seen for follow-up neurologist because the pt felt as if their device was no longer working. The pt also reports pain in the neck area. X-rays were performed and reviewed. It was reported that there are no visible lead fractures on the x-rays. It was also reported that the pt's jugular vein was "pasted" onto the vagus nerve and scar tissue has built up, therefore, revision surgery may not be performed. Review of the programming history concluded that within the last two months the device impedance increased to a dc dc code of 7 and limit indicating a possible device malfunction.

http://www.accessdata.fda.gov/scripts/cdrh/cfdocs/cfmaude/detail.cfm?mdrfoi__id=612038
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dennis100
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« Reply #11 on: May 13, 2011, 01:32:26 AM »

Event Date 05/19/2004
Event Type Injury
Patient Outcome Required Intervention;
Event Description
Reporter indicated that during device diagnostic testing at initial implant surgery, surgeon noted that the pt experienced neck spasms. Subsequent device diagnostic testing during initial implant surgery also resulted in the pt experiencing neck spasms. Further follow-up revealed that the surgeon initially placed the lead electrodes around the hypoglossal nerve. Surgeon then re-identified the vagus nerve and placed the lead electrodes without further incident.

http://www.accessdata.fda.gov/scripts/cdrh/cfdocs/cfmaude/detail.cfm?mdrfoi__id=530557

« Last Edit: September 25, 2015, 06:11:39 AM by dennis100 » Logged
dennis100
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« Reply #12 on: May 13, 2011, 04:05:45 AM »

Model Number 302-30
Event Type Malfunction
Event Description
Reporter indicated that device diagnostic testing at office visit resulted in high lead impedance (dc-dc code unk), indicating possible device malfunction. It was also reported that the pt experienced an increase in seizures. It is unk if the increase in seizures is above the pt's pre-vns baseline frequency. Revision surgery was performed. During revision surgery, neurosurgeon noted that the generator setscrew was stripped. Both the pulse generator and bipolar lead were then replaced, it is likely that the high lead impedance reading was a result of the negative electrode not being attached to the pt's vagus nerve.

http://www.accessdata.fda.gov/scripts/cdrh/cfdocs/cfmaude/detail.cfm?mdrfoi__id=612165

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dennis100
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« Reply #13 on: May 14, 2011, 09:57:09 AM »

Event Date 05/01/2003
Event Type Malfunction
Event Description
The device had been turned off approx one month prior to the surgery. It was also reported that only the lead was replaced during surgery. The surgeon reported that during the revision surgery, he observed a lot of fibrosis around the old lead/nerve interface and so he clipped the electrodes and implanted a new lead. The surgeon also stated that during the procedure he did not find any gross anamalies with the old lead and that the lead did not come off the nerve as the pt initially alleged. The surgeon further commented that he believes the fibrosis had kept the lead helicals firmly in place. The pt had complained of twitch with his sternocleidomastoid muscle during vns stimulation; this was the reasons for the revision surgery. The device was turned on after the surgery. Post-surgery, the pt complained of headaches, which reportedly resolved.

Event Description
Reporter indicated his lead came off the vagus nerve approx 3 months after the implant. The pt began experiencing muscle twitching in his neck. The pulse generator was reportedly inactivated 32 months after the implant and the pt no longer felt the muscle twitching. The pt recently underwent lead revision surgery. However, it is unk at this time if the lead was explanted, replaced with a new lead, or re-attached to the vagus nerve. The cause of this event is unk; the event is currently being investigated.

http://www.accessdata.fda.gov/scripts/cdrh/cfdocs/cfmaude/detail.cfm?mdrfoi__id=662891

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dennis100
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« Reply #14 on: May 14, 2011, 09:58:02 AM »

Event Date 04/01/2005
Event Type Malfunction
Event Description
The patient underwent revision surgery, at which time it was discovered that the lead electrodes were not attrached to the vagus nerve. Both the lead and generator were replaced. The burning sensation has resolved with the device replacement. The lead assembly was returned to manufacturer for analysis. The reported events of burning or heat sensations are not duplicate in the laboratory environment. Visual examination of the lead assembly identified incisions, punctures in the silicone tubing, and exposed sections of the lead coils; however, it is unknown whether these conditions existed during the implant life. The condition of the returned portion of the lead, in general, is consistent with conditions that typically exist following an explant procedure. The lead pin showed evidence of a proper mechanical and electrical connection as expected. The pulse generator was also returned to manufacturer for analysis. Device diagnostic testing was within normal limits, indicating proper device function. The elective replacement indicator was no, ruling out generator battery end of life. Visual examination performed prior to decontamination showed that the septum was cored and contained dried blood in the septum cavity. There were no performance anomalies or any condition found with the pulse generator that would have contributed to the reported events; however, if the septum was cored during the implant life, this may have been a contributing factor to the paresthesia. The likely cause of the patient's symptoms is the fact that the lead electrodes were not attached to the vagus nerve. The reason that the electrodes were not attached has been ascertained.

http://www.accessdata.fda.gov/scripts/cdrh/cfdocs/cfmaude/detail.cfm?mdrfoi__id=652946


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dennis100
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« Reply #15 on: May 14, 2011, 01:22:59 PM »

Event Date 04/20/2007
Event Type Malfunction
Event Description
Reporter indicated that a vns patient was not sensing normal stimulation upon the initial activation of the device. A systems diagnostics test was performed and the results were reported to be within normal limits. The output current was increased incrementally up to 3ma output current and the patient still did not sense the stimulation. X-rays were reviewed by manufacturer and it appeared that the anchor tether may not be attached to the vagus nerve. Additionally, the caudal (positive) electrode did not appear to be placed around the vagus nerve in the typical helical orientation, which is not what is typically seen unless it is due to the patient's anatomy. The patient had a surgical consult regarding the event. It is unknown if or when the patient scheduled for revision surgery. Attempts to obtain additional information from the surgeon and have been unsuccessful.

http://www.accessdata.fda.gov/scripts/cdrh/cfdocs/cfmaude/detail.cfm?mdrfoi__id=852324
« Last Edit: September 30, 2015, 02:55:51 AM by dennis100 » Logged
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« Reply #16 on: May 15, 2011, 12:22:21 PM »

Event Date 01/01/2005
Event Type Malfunction
Event Description
Device diagnostic testing at office visit resulted in lead impedance reading, indicating possible device malfunction. The elective replacement indicator was no, ruling out generator battery end of life as a likely cause of the high lead impedance test result. It was reported that device diagnostic testing performed approx nine months prior was within normal limits, indicating proper device function at that time. The pt no longer feels device stimulation and reported that one of his children had recently fallen on him, possibly causing damage the ncp system. Treating physician suspects a lead discontinuity and revision surgery is planned; however, the physician indicated that the pt may not have room left on his left vagus nerve since he had several leads already.

http://www.accessdata.fda.gov/scripts/cdrh/cfdocs/cfmaude/detail.cfm?mdrfoi__id=664208
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dennis100
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« Reply #17 on: May 16, 2011, 06:12:52 AM »

Event Date 01/01/2003
Event Type Injury
Patient Outcome Required Intervention;
Event Description
Reporter provided an op report that stated a patient was experiencing an "erosion of the electrodes through the area of his lower neck" that "probably represented acne infection with abcess, which communicated with the wire and because of the retained "foreign body," this lesion could not heal. The only way to control this was to remove the device. " follow-up with the physician's office indicated that the pt had developed small pimples around different parts of the body including the neck site around the lead area. The doctor stated that the pt's body was most likely rejecting the lead which was the suspected cause of the pimples around the pt's body. The infection was caused when the lead eroded through the surface of the skin. No pt manipulation is suspected.

http://www.accessdata.fda.gov/scripts/cdrh/cfdocs/cfmaude/detail.cfm?mdrfoi__id=861038
« Last Edit: September 25, 2015, 06:12:28 AM by dennis100 » Logged
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« Reply #18 on: May 16, 2011, 06:13:44 AM »

Event Date 04/30/2007
Event Type Injury
Patient Outcome Hospitalization; Required Intervention
Event Description
Reporter indicated that the patient began experiencing hoarseness 48 hours following implantation surgery. The patient's vns was not programmed on yet. The physician indicated that turning the vns device on made the patient's hoarseness worse. The patient was diagnosed with left vocal cord paralysis by an ent physician. Further information received indicated that "post-implantation of a 2mm lead the patient presented with the significant hoarseness and vocal cord paralysis, prior to initiation of stimulation. " revision surgery was performed in 2007. It was reported the doctor noticed "swelling in the electrode region causing pressure on the nerve. " the surgeon elected to remove the 2. 0 mm lead and plans to re-implant the patient with a 3. 0 mm lead in the future. It was indicated that the patient's hoarseness has improved about 80% since removal of lead.

http://www.accessdata.fda.gov/scripts/cdrh/cfdocs/cfmaude/detail.cfm?mdrfoi__id=862295
« Last Edit: September 25, 2015, 06:12:44 AM by dennis100 » Logged
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« Reply #19 on: May 16, 2011, 06:14:34 AM »

Event Date 01/01/2007
Event Type Malfunction
Patient Outcome Hospitalization;
Manufacturer Narrative
Device malfunction is suspected.

Event Description
Reporter indicated that the 'pt's electrodes were coming off the vagus nerve. " physician notes received by manufacturer indicated that the pt started to "have problems with seizure management" and was experiencing "pain over the left side of face, about the left eye, problems swallowing, problems speaking, and pain with tingling and burning referred into the arms, hands, and now sometimes legs. " "it appears that the lead attached to the left vagal nerve is not well attached and may actually be totally displaced. " the pt was admitted to the hospital, her settings were planned on being changed, and revision surgery planned in an attempt to resolve the pt's issues. Follow-up with the physician indicated that he looked at the pt's x-rays and did not see anything. He also explained that the normal mode diagnostics obtained were ok. Additionally, it was reported that the pt was experiencing headaches and jaw pain. The physician thinks tha it may have something to do with the pt's anatomy that causes the lead to come off. He explained that the pt was extremely psychotic prior to the vns and is now a "completely different person. " revision surgery was performed in 2007. Diagnostics were performed prior to surgery and obtained all normal results with a dcdc code of 3 and eri=no. It was reported that the surgeon found that there was inadequate strain relief "due to improper positioning of the tie downs, the lead was in the shape of a figure 8, and there was a great deal of scar tissue which was never removed from previous surgery that contributed to the pt's events. " the surgeon removed the lead implanted in 2006 and almost all of the scar tissue that was present on the vagus nerve of the pt. There was part of the scar tissue that he did not remove to avoid damage to the vagus nerve. The replacement lead's electrodes were positioned right below the original site of the scar tissue. Diagnostics performed after the surgery obtained normal results.

http://www.accessdata.fda.gov/scripts/cdrh/cfdocs/cfmaude/detail.cfm?mdrfoi__id=861962
« Last Edit: September 25, 2015, 06:13:11 AM by dennis100 » Logged
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« Reply #20 on: May 16, 2011, 08:38:55 AM »

Event Date 01/01/2006
Event Type Malfunction .
Event Description
Reporter indicated a pt had high impedance readings at an office visit, indicating a possible lead break. The pt was also experiencing an increase in seizures. The seizure increase was not greater than pre-vns baseline levels. Review of x-rays by the manufacturer revealed a suspicious area at the negative electrode that appears to be a break. Revision surgery is planned.

http://www.accessdata.fda.gov/scripts/cdrh/cfdocs/cfmaude/detail.cfm?mdrfoi__id=885326

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« Reply #21 on: May 16, 2011, 12:44:18 PM »

Event Date 03/15/2006
Event Type Malfunction
Event Description
Reporter indicated that high lead impedance was obtained via intraoperative diagnostic testing during a new implant procedure, indicating a possible lead malfunction. Lead was subsequently replaced during same procedure and was returned to manufacturer for product analysis. During analysis, it was noted that the "furthest electrode from the bifurcation has what appears to be silicone adhesive/elastomer coverage over the electrode area, which exceeds specification. Based on the product analysis findings, there is evidence to suggest that the condition of the furthest electrode ribbon surface would have contributed to the high impedance complaint. ".

http://www.accessdata.fda.gov/scripts/cdrh/cfdocs/cfmaude/detail.cfm?mdrfoi__id=889844


« Last Edit: May 16, 2011, 12:46:49 PM by dennis100 » Logged
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« Reply #22 on: May 16, 2011, 12:47:58 PM »

Model Number 302-30
Event Date 08/10/2005
Event Type Malfunction
Event Description
Reporter indicated that he received high lead impedance during multiple system diagnostics tests during a patient implant procedure. Troubleshooting did not resolve the issue. Reporter additionally indicated that "the positive electrode appeared to be abnormal" because "the electrode size appeared larger than the other electrodes when he removed the lead from the sterile packaging. " he then reported that it looked as if the positive electrode was not making a good connection with the nerve compared to the other two electrodes. " lead was then replaced during same procedure and returned to manufacturer for analysis. During analysis, measurements of the inner diameters performed on the electrodes showed that the diameters of both of electrodes did not meet manufacturer specification of approximately 50-60% of the circumference. It was additionally determined that due to the actual condition of the lead, it is unknown whether this condition was present prior to manipulation of the lead by the physician.

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

Event Description
Operative notes for the (b)(6) 2005 vns implant surgery were received to the manufacturer. After diagnostics testing noted high lead impedance, it was decided 'this lead is not a good lead' and it was not implanted. The surgeon also noted 'it had been apparent from the onset the coils were not in contact with the nerve and that this may have been a defective lead. ' a new lead was used without issues.

https://www.accessdata.fda.gov/scripts/cdrh/cfdocs/cfmaude/detail.cfm?mdrfoi__id=889846
« Last Edit: November 14, 2015, 12:46:04 PM by dennis100 » Logged
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« Reply #23 on: May 16, 2011, 12:48:30 PM »

Event Date 07/01/2007
Event Type Injury
Patient Outcome Required Intervention;
Event Description
Reporter indicated that the vns electrodes had been "pulled out" by the patient and that there was an infection at the site of extraction. The ncp generator and lead were explanted as a result of the events. Attempts to obtain additional information from the physician have been unsuccessful to date. Product analysis was completed on the ncp generator and lead, although the electrode portion of the lead was not returned for analysis. No anomalies were identified with the generator or portion of the lead returned.

http://www.accessdata.fda.gov/scripts/cdrh/cfdocs/cfmaude/detail.cfm?mdrfoi__id=902907
« Last Edit: September 25, 2015, 06:13:40 AM by dennis100 » Logged
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« Reply #24 on: May 17, 2011, 04:00:59 AM »

Event Date 08/22/2007
Event Type Malfunction
Event Description
Reporter indicated that during an initial vns therapy system implant surgery, the surgeon had trouble implanting the lead because the electrodes were not staying on the nerve. The surgeon also reported that he had manipulated the lead too much and chose to implant a new lead. The lead was returned to manufacturer for analysis. Product analysis on the returned lead portions revealed the closest electrode bifurcation was damaged showing bends in the electrode ribbon and partial detachment from the silicone helix. The likely cause of the damaged electrode is the force exerted during manipulation of the helix.

http://www.accessdata.fda.gov/scripts/cdrh/cfdocs/cfmaude/detail.cfm?mdrfoi__id=915355
« Last Edit: September 25, 2015, 06:14:01 AM by dennis100 » Logged
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« Reply #25 on: May 17, 2011, 04:02:14 AM »

Event Date 08/01/2007
Event Type Malfunction
Event Description
Initial reporter indicated that, the patient had been to surgery for a generator replacement for end of battery life and would be rescheduled for a total revision related to "malfunction of electrodes" at a later date. Physicians office reported that, the patient was unable to feel the adjustments being made to her device and was also experiencing pain in the neck region "which leads me to believe she a defective electrode". Further follow-up with the physician's office, it was reported the patient's vns was at complete end of battery life and no diagnostics could be performed preoperatively. In the or, it was discovered after replacing the patients generator and connecting it to the indwelling lead that the patient had high lead impedance. The patient was then scheduled for a full revision at a later date. The patient had their full revision surgery and good faith attempts are being made for product return for analysis.

http://www.accessdata.fda.gov/scripts/cdrh/cfdocs/cfmaude/detail.cfm?mdrfoi__id=914286
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« Reply #26 on: May 17, 2011, 04:03:46 AM »

Event Date 09/20/2007
Event Type Malfunction
Patient Outcome Hospitalization;
Manufacturer Narrative
X-rays were reviewed by the manufacturer. X-ray review showed the electrode placement was not what is typically seen. Although it can not be stated conclusively, the electrodes placement is consistent with other instances where the electrodes have become detached from the vagus nerve, or where the electrodes are attached, but the pt anatomy is a-typical. Device malfunction is suspected, but did not cause pt death.

Event Description
Reporter indicated the pt presented with high lead impedance on a system diagnostics test, indicating a possible lead malfunction. No trauma, pt manipulation or any other condition was reported that could have caused or contributed to the high lead impedance. The pt's generator was programmed off. X-rays were viewed by the manufacturer, and it appeared the electrode placement was not consistent with what is typically seen. Although it can not be stated conclusively, the electrodes placement is consistent with other instances where the electrodes have become detached from the vagus nerve, or where the electrodes are attached, but the pt anatomy is a-typical. The pt underwent vns therapy system replacement surgery. In the operative report the surgeon reported the "electrodes had shifted in their position. They had actually projected the vagus nerve anteriorly and were in a more horizontal position than expected. " it was also noted "the upper most electrode had partially eroded into the vagus nerve. Fortunately, there was no transection. The electrodes were then carefully removed intact. " the generator was replaced prophylactically. The generator was returned to the manufacturer, but the lead was discarded by the hospital staff. Therefore a product analysis can not be performed.

http://www.accessdata.fda.gov/scripts/cdrh/cfdocs/cfmaude/detail.cfm?mdrfoi__id=929776
« Last Edit: September 25, 2015, 06:14:31 AM by dennis100 » Logged
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« Reply #27 on: May 17, 2011, 04:05:35 AM »

Event Date 08/20/2007
Event Type Malfunction
Event Description
Reporter indicated that high lead impedance was discovered during a generator revision surgery. Pre-operative diagnostic testing was not possible as the generator was at eos and unable to communicate. Follow up with the treating physician revealed that there was no apparent cause for the high impedance. The lead and generator were repplaced and returned for analysis. The lead was found to have a coil fracture near the electrode bifurcation.

http://www.accessdata.fda.gov/scripts/cdrh/cfdocs/cfmaude/detail.cfm?mdrfoi__id=914949

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« Reply #28 on: May 17, 2011, 04:06:20 AM »

Event Date 09/07/2007
Event Type Malfunction
Patient Outcome Other;
Event Description
It was reported to mfr that a sys diagnostic test performed at the vns pts follow up visit due to a recent increase in seizure activity, revealed high lead impedance. The increase in seizures was reported by the caregiver to be above the pre-vns baseline. The treating physician believes that a possible cause for the high lead impedance could be due to the pt repetitively reaching over a "half door" located at the pt's residence, which may have resulted in damaging the lead. X-rays were taken of the left chest and neck to assess the continuity of the system. The x-rays were reviewed by the mfr and no obvious discontinuities or anomalies were observed that could be contributing to the high lead impedance. The pt's device was programmed off at the time the high lead impedance was noted. The believed cause for the increase in seizures was due to lack of vns therapy. The pt had surgery to replace the problematic lead. During surgery, a lead break was discovered in the lead in the neck area and the positive helical was described by the surgeon as not being on the nerve. The explanted lead has been returned to mfr and is pending the completion of product analysis.

http://www.accessdata.fda.gov/scripts/cdrh/cfdocs/cfmaude/detail.cfm?mdrfoi__id=925128
« Last Edit: September 25, 2015, 06:15:01 AM by dennis100 » Logged
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« Reply #29 on: May 18, 2011, 02:40:06 AM »

Event Date 01/01/2007
Event Type Malfunction
Event Description
Initial reporter indicated the pt was having worsening seizure activity over the last 6-9 months. The seizures reported were at the pt's preimplantation seizure rate. The device was interrogated and high lead impedance was discovered indicating a possible lead malfunction. X-rays were reviewed by the pt's treating physician "who thought there may be an indication of one of the coils come off the vagus nerve. " the pt had not been seen in the clinic for at least 15 months, there was no report of any falls as the child cannot walk and is in a chair continuously. It was additionally reported "he has grown a great deal since implantation. " the pt underwent full revision surgery. Cyberonics is pending receipt of the explanted products for analysis. It was reported the "surgeon could not see exactly where the problem had occurred but thought the 'loop' had disappeared. ".

http://www.accessdata.fda.gov/scripts/cdrh/cfdocs/cfmaude/detail.cfm?mdrfoi__id=959506

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