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dennis100
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« Reply #210 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
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dennis100
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« Reply #211 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
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dennis100
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« Reply #212 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
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dennis100
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« Reply #213 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
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dennis100
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« Reply #214 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
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dennis100
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« Reply #215 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
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dennis100
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« Reply #216 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
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dennis100
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« Reply #217 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
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dennis100
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« Reply #218 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
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dennis100
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« Reply #219 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
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dennis100
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« Reply #220 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
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dennis100
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« Reply #221 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
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dennis100
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« Reply #222 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
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dennis100
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« Reply #223 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
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dennis100
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« Reply #224 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
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« Reply #225 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
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« Reply #226 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
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« Reply #227 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
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« Reply #228 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
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« Reply #229 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

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« Reply #230 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
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« Reply #231 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
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« Reply #232 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
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« Reply #233 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
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dennis100
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« Reply #234 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
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dennis100
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« Reply #235 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
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dennis100
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« Reply #236 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
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dennis100
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« Reply #237 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
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dennis100
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« Reply #238 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
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dennis100
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« Reply #239 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
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