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dennis100
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« Reply #390 on: February 15, 2019, 03:28:25 AM »

Model Number 302-20
Event Date 01/01/2010
Event Type  Malfunction   
Event Description
It was initially reported by the physician that the patient was having a full revision surgery due to high lead impedance. Patient no longer feels stimulation and she is not certain when this occurred. Patient was taken into surgery and it was observed that there was a lot of lead near the generator. Surgeon replaced the generator first and performed diagnostics and found high impedance. The surgeon then attempts to remove the old lead and he noticed that there was a lot of fibrosis at the nerve. He also observed that the negative electrode was not on the nerve. The vagus nerve appeared to be bent at 90 degrees angle indicating something was likely pulling on the nerve. The surgeon removed the old lead and replaced it with the new lead. Fibrosis was removed from the nerve. Good faith attempts to obtain additional information has been unsuccessful.
 
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=1634008
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dennis100
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« Reply #391 on: February 15, 2019, 03:29:27 AM »

Model Number 302-20
Event Date 03/05/2015
Event Type  Malfunction   
Manufacturer Narrative
Device failure is suspected, but did not cause or contribute to a death or serious injury.
 
Event Description
On (b)(6) 2015 it was reported that the patient¿s vns was interrogated and found to be at end of service with pulse disabled as well as high impedance during diagnostics. Surgery took place that day and when the generator was replaced, high impedance was still observed. Therefore they did a full revision. There was no noticeable lead fracture but the electrodes were in an inverted position. It was reported that the explanted products could not be returned for product analysis as the hospital discards them.

https://www.accessdata.fda.gov/scripts/cdrh/cfdocs/cfmaude/detail.cfm?mdrfoi__id=4625691
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dennis100
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« Reply #392 on: February 19, 2019, 03:24:14 AM »

Model Number 302-20
Event Date 03/19/2015
Event Type  Injury   
Event Description
It was reported that the hospital does not return explanted products.
 
Manufacturer Narrative

Event Description
The patient had previously had generator and a portion of the lead explanted. During scheduled replacement surgery on (b)(6) 2015, the surgeon decided to abort the surgery. There was reportedly too much scar tissue, and the lead was unable to be removed from the nerve. The surgeon also believes that it would have been very difficult placing the new electrodes.

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dennis100
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« Reply #393 on: February 21, 2019, 01:47:48 PM »

Model Number 105
Device Problems Fracture; High impedance
Event Date 03/16/2015
Event Type  Malfunction   
Event Description
The explanted generator and lead have been received by the manufacturer for analysis. However, analysis has not been completed to date.
 
Event Description
Analysis was completed on the explanted generator and lead. Analysis of the generator showed no anomalies. The device output signal was monitored for more than 24 hours, while the generator was placed in a simulated body temperature environment. Results showed no signs of variation in the pulse generator's output signal and demonstrated that the device provided the expected level of output current for the entire monitoring period. The pulse generator diagnostics were as expected for the programmed parameters. In addition, a comprehensive automated electrical evaluation showed that the pulse generator performed according to functional specifications analysis of the lead showed a set of setscrew marks near the end of the connector pin indicating the lead had not been fully inserted into the cavity of the generator. The marks are evidence of a potentially insufficient mechanical contact between conductive surfaces of the generator and connector ring, resulting in a suspect electrical connection to the lead. X-ray suggests canted spring was marginally connected to the connector ring. Canted spring indentations were observed on the rear end of the small front o-ring. During the visual analysis of the returned 373mm portion the (+) white and (-) green electrode ribbons were observed to be embedded in what appeared to be remnants of dried body tissue. This condition may have prevented the electrode ribbons from coming in contact with the vagus nerve. With the exception of the observed tissue-covered electrode ribbons and the set of setscrew marks observed near the end of the connector pin the condition of the returned lead portions is consistent with conditions that typically exist following an explant procedure. No other obvious anomalies were noted. Continuity checks of the returned lead portions were performed, during the visual analysis, and no discontinuities were identified.
 
Event Description
It was reported that device diagnostics resulted in high impedance. No patient manipulation or trauma occurred that is believed to have caused or contributed to the high impedance. It was reported that device diagnostics were within normal limits during implant. X-rays were taken and sent to manufacturer for review. Review of x-rays did not identify any obvious discontinuities with the vns system. The presence of a micro-fracture could not be ruled out.
 
Manufacturer Narrative
Device manufacturing records were reviewed. Review of manufacturing records confirmed that the lead passed all functional tests prior to distribution.
 
Manufacturer Narrative
Device failure is suspected, but did not cause or contribute to a death or serious injury.
 
Event Description
Additional information was received that the patient's vns system was explanted due to death (b)(6) 2015. The death is not thought to be related to vns. Additional information was received that high impedance was not seen for this patient during initial implant. Also, the patient's device was not disabled following high impedance observation. Review of manufacturing records confirmed that the generator and lead passed all functional tests prior to distribution.

https://www.accessdata.fda.gov/scripts/cdrh/cfdocs/cfmaude/detail.cfm?mdrfoi__id=4673669
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dennis100
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« Reply #394 on: March 06, 2019, 01:31:49 AM »

Model Number 302-20
Device Problems Detachment Of Device Component; High impedance
Event Date 07/17/2015
Event Type  Malfunction   
Event Description
Additional information was received that the patient's pain had been occurring in the patient's neck prior to the generator and lead replacement surgery. The pain began occurring following a settings increase. Thus, the settings were decreased which helped the pain. The pain was thought to perhaps have been caused by the detached electrode. No additional relevant information has been obtained to date.
 
Event Description
Analysis was completed on the patient's explanted generator. Analysis showed that the generator performed according to functional specifications. Analysis of the generator concluded that no abnormal performance or any other type of adverse condition was found. An analysis was performed on the returned lead portion. Note that a portion of the lead assembly including the electrodes was not returned for analysis and therefore a complete evaluation could not be performed on the entire lead product. No 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 portion were performed, during the visual analysis, and no discontinuities were identified.
 
Manufacturer Narrative
Describe event or problem; corrected data: the previously submitted mdr inadvertently failed to report the device evaluation.
 
Manufacturer Narrative

Event Description
Clinic notes were received and indicated that the patient had experienced pain associated with stimulation. There was also a report of a settings adjustment which helped with the pain. The patient then underwent a prophylactic generator replacement surgery on (b)(6) 2015. However, pre-operative system diagnostics resulted in high impedance detected on the patient's vns system. Thus, the lead was replaced as well. It was reported that during the lead replacement, it was seen that the positive electrode and anchor tether of the lead had become detached from the patient's vagus nerve, leaving only the negative helical electrode still attached. No lead fractures were noted. It was unknown how the lead had become partially detached form the nerve. The diagnostics were normal following the generator and lead replacement. The explanted generator and lead were received by the manufacturer for analysis. However, analysis has not been completed to date.

https://www.accessdata.fda.gov/scripts/cdrh/cfdocs/cfmaude/detail.cfm?mdrfoi__id=5002392
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dennis100
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« Reply #395 on: March 09, 2019, 02:11:32 AM »

Model Number 303-20
Device Problem Detachment of Device or device Component
Event Date 01/03/2019
Event Type  Malfunction   
Event Description
It was reported by a company representative that the patient experienced a shocking feeling in their neck soon after lead and generator placement surgery. The physician indicated that x-rays were taken that indicated the electrodes were not securely placed on the nerve. The physician indicated that the patient underwent a generator and lead replacement surgery. The suspect product (lead) was reportedly not available for return. No further relevant information has been received to date.

https://www.accessdata.fda.gov/scripts/cdrh/cfdocs/cfmaude/detail.cfm?mdrfoi__id=8296459
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dennis100
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« Reply #396 on: March 12, 2019, 03:07:42 AM »

Model Number 302-20
Event Date 10/01/2014
Event Type  Malfunction   
Event Description
On (b)(6) 2014 it was reported that the patient has high impedance on all diagnostics, so they turned the device off and ordered x-rays for the patient. The patient¿s last visit was in (b)(6) 2014 and the diagnostics were normal at that time. The patient¿s caretaker said she hadn¿t noticed the patient¿s voice go hoarse with stimulation in a while so thinks it may not have been working properly for a few months. They have not had any major falls or injuries. Although surgery is likely, it has not occurred to date. An x-ray assessment was performed on the x-ray images for the patient. The generator was visualized in the patient¿s left chest. The lead appeared to be intact at the lead pin. The filter feed thru wires appeared to be intact. The lead pin appeared to be fully inserted into the connector block. The electrodes appeared to be in alignment; however, the electrodes appear to be inverted on the patient¿s vagus nerve. Based on the x-rays received, the cause of the high impedance cannot be determined. However, a micro-fracture cannot be ruled out.
 
Event Description
The patient had lead revision surgery on (b)(6) 2016. The generator was not replaced. System diagnostics were performed during the surgery, and high impedance was identified prior to the lead replacement. Once the lead was replaced, there was normal impedance. The explanted lead has not been received to date.
 
Event Description
The device history record of the lead was reviewed, and the device conformed to all specifications prior to release. The explanted lead was received on 05/09/2016. Analysis was approved on 06/02/2016. A break was identified in the positive coil. The positive coil showed that pitting of electro-etching conditions have occurred at the break location. One strand of the positive quadfilar coil showed minor appearance suggesting that a stress-induced fracture occurred in at least one strand. However, due to pitting and mechanical distortion (smoothed surfaces) the fracture mechanism of strands could not be ascertained. Other than the above mentioned observations and typical wear and explant related observations, no other anomalies were identified in the returned lead.
 
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=4268315
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dennis100
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« Reply #397 on: March 14, 2019, 06:00:48 AM »

Model Number 302-20
Device Problem Adverse Event Without Identified Device or Use Problem
Event Date 10/04/2015
Event Type  Malfunction   
Event Description
It was reported that vns device diagnostics resulted in high impedance (dcdc converter 7). It was reported that the patient experienced an increase in seizures. It was reported that the device was turned off on (b)(6) 2015. X-rays were taken but not provided to the manufacturer to date for assessment. Review of manufacturing records confirmed that both, the generator and the lead passed all functional tests prior to distribution. Further information was later received indicating that the patient underwent full replacement surgery on (b)(6) 2015. It was reported that device diagnostics with the new lead and generator were within normal limits. The explanted devices were not returned to the manufacturer for analysis.
 
Event Description
X-rays were provided to the manufacturer for review. The generator appears on the x-rays to be placed in upper chest in normal arrangement. The pin connector appears to be not fully inserted. But due to the quality and angle of the provided images, this could not be confirmed. The electrodes appeared to be placed in abnormal arrangement. The upper of the electrode was implanted very low in the neck, not as specified in labeling. Strain-relief bend and loop seemed to have been used. One tie-down was found holding the lead but it's unable to assess if they are placed as specified in labeling. A portion of lead behind the generator could not be assessed. No suspected lead break was found on the visible part of the lead. Further information received confirmed that the lead was implanted very low in the neck, as found on the provided x-rays, because as indicated by the surgeon: "this is his surgical technique".

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dennis100
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« Reply #398 on: March 16, 2019, 01:39:13 AM »

Model Number 302-30
Device Problems Break; High impedance
Event Date 05/17/2015
Event Type  Malfunction   
Event Description
It was reported by the neurologist the patient was scheduled for vns surgery as the vns was checked showing high impedance and it is unsure if the lead pin is out or if a new lead needs to be placed. It was also reported the patient's device was turned off on (b)(6) 2015. It was later reported the patient underwent surgery on (b)(6) 2015 and the lead and the generator were both replaced. The lead was replace due to high impedance and the generator was prophylactically replaced. Additionally, it was reported there was a lead break at the strain relief bend, right by the tie down. It was also clarified the generator was replaced prophylactically as the physicians were unclear how long the device had been broken and were not comfortable using the old device due to the broken lead and risk of infection from taking the generator out, then putting it back in after removing and replacing with the new lead. The lead and the generator were received. Analysis is expected but has not been completed to date.
 
Event Description
Product analysis found that the high impedance most likely occurred on (b)(6) 2015 as the impedance value was noted to have changed from 1224 ohms to 11619 ohms on that date. It was found through testing that the generator performed according to functional specifications. The final electrical test shows and ifi = no condition. There were no performance or any other type of adverse conditions found with the pulse generator. Analysis was completed on the returned lead portions and lead fractures were confirmed. It should be noted that portions of the electrodes were not returned for analysis; therefore a complete evaluation could not be performed on the entire lead product. Fractures were found on all three coil strands. One of the coils had extensive pitting that prevented identification of the fracture type. It was noted that all three broken coil strands were mechanically damaged which prevent identification of the fracture type, with evidence of a stress induced fracture, which most likely completed the fracture on all three broken coil strands. One of the coil strands was identified as having evidence of a stress induced fracture with mechanical damage and pitting. Determination could not conclusively be made on the fracture mechanism. It is believed that stimulation was present for a certain period of time as evidenced by the presence of metal pitting. The abraded openings found on the outer silicone most likely provided the leakage path for the dried remnants of what appeared to have once been body fluids inside the outer silicone tubing. White deposits were observed in various locations. Energy dispersion spectroscopy was performed on the deposit observed on the connector boot and identified the deposit as containing silicon, phosphorus, sodium, magnesium, and calcium. It was found that the returned white electrode ribbon appeared to be embedded in what appeared to be remnants of dried body tissue. This condition may have prevented the white electrode ribbon from coming in contact with the vagus nerve. With exception of the observed discontinuities and the tissue covered white electrode ribbon, the condition of the returned lead portions is consistent with conditions 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. Based on the findings in the product analysis lab, there is evidence to suggest discontinuities in the returned portions of the lead which may have contributed to the stated allegations.
 
Manufacturer Narrative
This information was inadvertently left off of supplemental #01 mfr. Report.

https://www.accessdata.fda.gov/scripts/cdrh/cfdocs/cfmaude/detail.cfm?mdrfoi__id=5126663
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dennis100
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« Reply #399 on: March 18, 2019, 02:03:36 AM »

Event Date 11/03/2015
Event Type  Malfunction   
Event Description
It was reported that high impedance (dc dc code - 7) was observed on vns patient's system. The device was then disabled. No patient adverse events were reported. X-rays were taken and sent to the manufacturer for review. The generator appears to be placed in the middle of the chest not as recommended in our labeling. The pin connector appears to be fully inserted. The electrodes appeared to be placed in abnormal arrangement: seems to be implanted too low in the neck, in the upper chest. It's unable to assess if a strain relief or loop were used, due to the quality of the provided x-rays. One tie-down was found holding the lead but not as specified by labeling. There is a large portion of the lead coiled around the electrode, which is unable to be assessed. There is no lead behind the generator. No clear lead breaks or sharp bends were found in the visible parts. A micro-fracture could not be ruled out. No known surgical interventions have been performed to date. No additional relevant information has been received to date.

https://www.accessdata.fda.gov/scripts/cdrh/cfdocs/cfmaude/detail.cfm?mdrfoi__id=5251293
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« Reply #400 on: March 18, 2019, 02:04:37 AM »

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

https://www.accessdata.fda.gov/scripts/cdrh/cfdocs/cfmaude/detail.cfm?mdrfoi__id=5257603
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« Reply #401 on: March 20, 2019, 10:45:40 AM »

Model Number 302-20
Device Problems Retraction Problem; Low impedance
Event Date 10/28/2015
Event Type  Malfunction   
Event Description
It was reported that during generator replacement surgery for end of service the surgeon disconnected the generator from the lead and then attempted to pull the lead from the patient's back side to re-tunnel the lead to the chest area. When the surgeon pulled the lead it got hung up in the patient's body and when the surgeon pulled on it the lead wires started retracting in the tubing. A new generator was attached to the lead and device diagnostics showed low impedance (<600 ohms). The surgeon did not obtain consent for lead replacement, so the lead was cut and explanted and a new generator was not placed. The patient was closed and rescheduled for lead replacement. No known surgical interventions have been performed to date.
 
Event Description
It was reported that the explanted devices were discarded; therefore, no product analysis can be performed. An implant card was received indicating that the patient underwent generator and lead reimplant on (b)(6) 2015. The surgeon indicated that he believed the lead electrodes were not on the nerve which he identified while dissecting the lead electrodes off of the nerve to reimplant the new lead. The surgeon indicated that the patient's anatomy was a little different than normally seen and an ultrasound was used to help determine the lead placement. The new generator was placed at the patient's chest. Device diagnostics were within normal limits.

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« Reply #402 on: March 21, 2019, 12:59:10 AM »

Model Number 302-20
Event Date 10/06/2015
Event Type  Malfunction   
Event Description
It was reported that vns system implanted in the patient was tested and system diagnostics returned high impedance with dcdc code 7 and neos no. X-rays were taken and sent to the manufacturer for review. The generator appears to be placed under the right arm in an abnormal arrangement. The filter feed-through wires appears to be intact. The insertion of the lead-pin connector could not be fully assessed due to the orientation of the generator in the x-rays and the quality of images, it appears to be not fully inserted. The electrodes appeared to be placed in abnormal arrangement, not in the neck. A strain-relief bend and a loop were not used. Only one tie-down was found holding the upper lead body. Part of the lead appeared to be behind the generator and could not be assessed. No clear lead breaks or sharp angles were found in the parts of the lead that could be assessed. It was reported by the physician that the device was not switched off yet. No known surgical interventions have occurred to date. No patient adverse events were reported to date.
 
Event Description
Further information was received from the facility, indicating that the patient underwent full replacement surgery on (b)(6) 2016. The lead was replaced due to lead discontinuity and the generator was prophylactically replaced. Review of manufacturing records confirmed that both, the generator and the lead passed all functional tests prior to distribution. It was reported that the explanted devices will not be returned to the manufacturer as they were discarded. Therefore, no analysis results could be provided. No additional information was provided to date.

https://www.accessdata.fda.gov/scripts/cdrh/cfdocs/cfmaude/detail.cfm?mdrfoi__id=5194237
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« Reply #403 on: March 26, 2019, 02:14:38 AM »

Model Number 303-20
Device Problem Appropriate Term/Code Not Available
Event Date 12/01/2015
Event Type  Injury   
Event Description
It was reported on (b)(6) 2015 that the patient was experiencing a painful, jolting sensation in her neck. The pain was constant. The device was turned down from 1. 75ma to 1. 25ma, but the patient reported that it was still painful. The date of onset of the pain was unknown. No known trauma had occurred. The physician performed diagnostics, and the impedance was within normal limits at 2800 ohms. It was reported on (b)(6) 2015 that the patient was referred for generator and lead replacement surgery with the device likely programmed to not delivery therapy until surgery. An implant card was later received reporting that the patient had lead replacement on (b)(6) 2015 due to pain at the lead site. The generator was not replaced. No additional relevant information has been received to date. The explanted lead has not been received by the manufacturer for analysis to date.
 
Event Description
Additional information was received from the surgeon reporting that he was observed during lead replacement surgery that one of the helicals was off of the vagus nerve, so he believes this was causing the painful stimulation to the patient's muscles. There was no particular event that was known or believed to have contributed to the helical coming off the nerve, but he notes that she does have tonic-clonic seizures so it may have occurred from a seizure. The helical appeared to be pulled medially and pulled quite a bit. The device was turned off prior to surgery for the pain. He has not heard from the patient since surgery, so takes that as a good sign that her pain has improved/resolved. No further information was provided. The explanted lead was received by the manufacturer for analysis. However, analysis has not been completed to date.
 
Event Description
Analysis of the lead was also completed. No 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 no evidence to suggest a discontinuity in the returned portions of the device. Note that since the (-) green electrode was not returned, an evaluation and resulting commentary cannot be made on that portion of the lead.

https://www.accessdata.fda.gov/scripts/cdrh/cfdocs/cfmaude/detail.cfm?mdrfoi__id=5359167
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« Reply #404 on: March 31, 2019, 07:11:33 AM »

Model Number 302-20
Event Date 04/08/2016
Event Type  Malfunction   
Event Description
It was reported that high impedance was observed on vns patient's system. The patient was due to undergo generator replacement surgery, when high impedance was identified; the vns patient's device was tested and system mode diagnostic results revealed high impedance (dc dc code 7) and near end of service = no. It was reported that the device replacement surgery was performed. The patient's vns system was tested upon connection of the new generator to the existing lead and high impedance persisted. It was reported that the newly implanted device was disabled. Review of the available programming and diagnostic history showed normal diagnostic results through (b)(6) 2012. Additional information was received indicating that the generator was replaced due to battery depletion. The return of that explanted device to the manufacturer is expected but it has not been received to date. It was reported that a lead revision due to lead discontinuity is planned. No known surgical interventions have occurred to date.
 
Event Description
The explanted generator was received to the manufacturer on 04/28/2016. Analysis of the returned generator was completed. The generator performed according to functional specifications. During the product analysis there were no anomalies found with the pulse generator.
 
Event Description
Further information was received indicating that the patient underwent lead replacement surgery on (b)(6) 2016. The lead was replaced due to lead discontinuity. The patient's vns system was tested upon connection of the new lead to the generator and system diagnostics returned impedance results within normal limits with 1568 ohms. The explanted lead was returned to the manufacturer on 06/09/2016. Analysis is underway but it has not been completed to date.
 
Event Description
An analysis was performed on the returned lead portions and the reported allegations of "fracture of leads" were confirmed. Note that the (-) green electrode was not returned for analysis and therefore a complete evaluation could not be performed on the entire lead product. During the visual analysis of the returned 40mm portion the (+) white electrode quadfilar coil appeared to be broken approximately 19mm from the electrode bifurcation. Scanning electron microscopy was performed and identified the area as having extensive pitting which prevented identification of the coil fracture type. Pitting was observed on the coil surface. During the visual analysis of the returned 9mm portion the end of the (+) white electrode quadfilar coil appeared to be broken approximately 18mm past the end of the cut inner silicone tubing. Scanning electron microscopy was performed and identified the area on two of the broken coil strands as having evidence of a stress induced fracture (fatigue appearance) with mechanical damage and pitting. The area on the remaining broken coil strands was identified as being mechanically damaged which prevented identification of the coil fracture with pitting. Flat spots and pitting were observed on the coil surface. 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. 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, magnesium and calcium. During the visual analysis the (+) white electrode ribbon appeared to be embedded in what appeared to be remnants of dried body tissue. This condition may have prevented the (+) white electrode ribbon from coming in contact with the vagus nerve. With the exception of the observed discontinuity and the tissue-covered (+) white electrode ribbon the condition of the returned lead portions is consistent with conditions that typically exist following an explant procedure. No other obvious anomalies were noted. The setscrew marks found on the lead connector pins 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. Based on the findings in the product analysis lab, there is evidence to suggest a discontinuity in the returned portions of the device which may have contributed to the stated allegations of high impedance. Note that since the (-) green electrode was not returned for analysis, an evaluation and resulting commentary cannot be made on that portion of the lead. However, the positive electrode condition may have contributed to the reported ¿high impedance¿.

https://www.accessdata.fda.gov/scripts/cdrh/cfdocs/cfmaude/detail.cfm?mdrfoi__id=5614469
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« Reply #405 on: April 01, 2019, 12:40:53 AM »

Event Date 02/04/2016
Event Type  Malfunction   
Event Description
It was reported that high impedance (dcdc 7) was observed on vns patient's system. Normal mode and system mode diagnostics were run and high impedance were found (dcdc 7). It was reported that the device was then disabled. X-rays were taken and sent to the manufacturer for review. The generator appears in the upper left chest in a normal placement. The filter feed-through wires appeared to be intact. The lead connector pin is fully inserted into the generator connector block. The electrode appears to be placed in abnormal arrangement (the negative electrode appears to be placed distal to head) but this could not be confirmed due to poor quality of the image. It's unable to assess if the strain-relief bend and loop are presents. No tie-down was found holding the lead. A portion of lead behind the generator could not be assessed. No suspected lead break was found on the visible part of the lead. Further information was received from the physician, indicating that the patient's generator was implanted in 2014. It's unknown if any patient trauma or manipulation occurred that could be the cause of the suspected lead fracture. As reported by the parents to the physician, the patient's seizures were stable until (b)(6) 2016, without explanation. The last device checking in (b)(6) 2015 found that the parameters / settings were normal. During a clinic visit on (b)(6) 2016, high impedance was found. The device was then switched off that day. It was reported that lead revision is planned. No known surgical interventions have been performed to date.

https://www.accessdata.fda.gov/scripts/cdrh/cfdocs/cfmaude/detail.cfm?mdrfoi__id=5488882
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« Reply #406 on: April 04, 2019, 12:52:39 AM »

Event Type  Malfunction   
Manufacturer Narrative

Event Description
It was reported that vns patient was due to have lead and generator replaced. Additional information was received that the reason for replacement was high impedance. It was reported that patient had the lead broken in the axilla; moreover at surgery the lead was not on the vagal nerve and was placed quite superficial to it. Attempts for additional relevant information have been unsuccessful to date.

https://www.accessdata.fda.gov/scripts/cdrh/cfdocs/cfmaude/detail.cfm?mdrfoi__id=5754828
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« Reply #407 on: April 04, 2019, 12:53:31 AM »

Model Number 302-20
Event Date 05/31/2016
Event Type  Malfunction   
Manufacturer Narrative

Event Description
It was reported that high impedance (>=10000 ohms. ) was observed on vns patient's system. It was reported that the patient had been feeling pain at neck for two weeks. On (b)(6) 2016, the patient's device was programmed at output current 1. 5ma, pulse width 500¿sec, frequency 30hz, on time 30sec and off time 5min. It was reported that the generator was turned off that day. It was reported that x-rays will be performed to see a possible lead discontinuity which could probably be due to a fall. A complete surgical revision will be scheduled but no known surgical interventions have been performed to date. Additional information was received indicating that x-rays have not yet been done, because the parents are quite reluctant about that. It was reported by the physician that in theirs records, there is a notification of the electrode wire-protuberance under the patient¿s skin on the neck; this was on (b)(6) 2014. No coincidental trauma and pain were observed; the device was working normally. It was reported that ultrasound investigation was performed that time, and no structural changes were described: the lead did not look interrupted.
 
Event Description
Further information was received indicating that the patient underwent lead revision surgery on (b)(6) 2016. The lead was replaced due to high impedance. The patient's vns system was tested upon connection of the new lead to the existing generator and system diagnostics returned impedance results within normal limits with 1480 ohms. Review of manufacturing records confirmed all tests passed for the concerned lead prior to distribution. It was reported that the explanted lead will not be returned to the manufacturer for analysis as it was disposed. Additional information from the physician indicated that the patient is now ok with a new e lead in place. It was reported that the patient never had any fall, blow or any other trauma in the neck region or area of vns generator. The lead protuberance appeared suddenly on (b)(6) 2010, under the skin on the lower part of her neck. When this happened, an ultrasound investigation was performed and no other intervention was taken; the patient was doing well, had no pain and very rare seizures and her mother reported that vns works well (hoarseness of patient voice). Later in (b)(6) 2016, the protuberance disappeared; the physician thinks that it was the moment when the electrode finally slipped completely from the vagal nerve. As it turned out during the revision, this protuberance was a part of electrode (a non-active one, the ground) that slipped from the vagal nerve. X-ray performed before the surgical procedure, indicated that one electrode was not in the correct place. It was reported by the physician that the reason must be an inappropriate position-fixation of electrodes when implanted.
 
Event Description
Additional information was received from the physician indicating that the day of the implant, on (b)(6) 2014, the device was tested and system diagnostics returned impedance results within normal limits with 1480 ohms. It was reported that on (b)(6) 2014 (after the lead protuberance appeared on (b)(6) 2014), the vns system was still ok and system diagnostics returned impedance results within normal limits with 2194 ohms.

https://www.accessdata.fda.gov/scripts/cdrh/cfdocs/cfmaude/detail.cfm?mdrfoi__id=5731782
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« Reply #408 on: April 06, 2019, 12:30:08 AM »

Device Problem Adverse Event Without Identified Device or Use Problem
Event Date 09/12/2018
Event Type  Injury   
Event Description
Article titled "improved quality of life and cognition after early vagal nerve stimulator implantation in children" was reviewed and three adverse events were identified for the patients studied within the cohort. 3 of the patients developed infections post implant and 1 of those patients required revision surgery due to the infection. 1 patient passed away prior to the study (captured in mfr. Report # 1644487-2019-00452) 1 patient had disconnection of their electrodes from the vagus nerve that required revision surgery(captured in mfr. Report # 1644487-2019-00454). It was reported that there was no permanent morbidity due to these events. No further relevant information has been received to date.

https://www.accessdata.fda.gov/scripts/cdrh/cfdocs/cfmaude/detail.cfm?mdrfoi__id=8404598
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« Reply #409 on: April 10, 2019, 01:22:05 AM »

Model Number 302-20
Event Date 06/30/2016
Event Type  Malfunction   
Event Description
It was reported that a patient had full revision surgery due to battery depletion. It was later reported that the lead was replaced due to the electrode being detached from the nerve. The explanted generator and lead were received on 07/05/2016. Analysis of the generator identified that the device exhibited current consumption rates that are within specification, thereby demonstrating normal battery depletion to an end-of-service condition. The electrical performance of the generator were used to conclude that no anomalies exist and the eos condition is an expected event. The module performed according to functional specifications. There was no condition noted during the product analysis evaluation that would suggest any anomaly with the device. The explanting surgeon confirmed that the lead was not detached from the nerve. High impedance was identified, and there was fluid inside the outer tubing that brought the surgeon to believe that the lead wires had been compromised. Analysis of the lead identified two lead breaks and corrosion at the break locations. Due to wear at one of the break locations, the fracture mechanism could not be determined. The other break appeared to be due to stress/mechanical damage. The electrodes were not returned for analysis, so a complete evaluation could not be performed on the entire product. With the exception of the observed discontinuity the condition of the returned lead portions was consistent with conditions that typically exist following an explant procedure. No other obvious anomalies were noted.

https://www.accessdata.fda.gov/scripts/cdrh/cfdocs/cfmaude/detail.cfm?mdrfoi__id=5821251
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« Reply #410 on: April 15, 2019, 12:37:54 AM »

Model Number 302-20
Event Type  Malfunction   
Event Description
It was reported the patient needed to be scheduled for a full vns revision due to high impedance. Attempts for additional relevant information have been unsuccessful to date.
 
Event Description
It was later reported the patient underwent full revision surgery on (b)(6) 2016. It was noted the patient had to be implanted on the right side as there was too much scar tissue and too many electrodes and anchor tethers on the left vagus nerve and there was no more room for an additional implant. It was noted the generator was replaced due to neos = yes (near end of service) and that the lead was replaced due to the high impedance observed. After the new generator and lead were replaced, the diagnostics were confirmed as ok. Attempts for additional relevant information have been unsuccessful to date.
 
Event Description
Additional information was received noting the devices were discarded after surgery. Therefore, the devices are not expected for return and no analysis will be performed.

https://www.accessdata.fda.gov/scripts/cdrh/cfdocs/cfmaude/detail.cfm?mdrfoi__id=5857766
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« Reply #411 on: April 15, 2019, 12:38:42 AM »

Model Number 303-20
Event Date 12/07/2015
Event Type  Injury   
Manufacturer Narrative
(b)(4).
 
Event Description
It was reported that the patient had significant swelling at the electrode and generator sites. It was initially thought that the patient had an infection, but that was ruled out. The patient then had a nuclear medicine scan, which showed that the patient had lymphatic fluid in the soft tissue surrounding the electrode site and was leaking down to the chest pocket as well. The patient was feeling painful stimulation in the neck, which the physician attributed to the electrode site being irritated and swollen. It was determined that the fluid collection was due to the implant location of the electrodes. The physician performed lead revision surgery on (b)(6) 2016 to replace the lead and position the new electrodes in a different location on the nerve. The physician did not observe any fluid when he was performing the lead revision surgery. The explanted lead was received on (b)(6) 2016. Analysis was approved on (b)(6) 2016. Note that since a portion of the lead (including the electrode array) was not returned for analysis, an evaluation and resulting commentary could not be made on that portion of the lead. Other typical wear and explant related observations, no anomalies were identified in the returned lead portion.

https://www.accessdata.fda.gov/scripts/cdrh/cfdocs/cfmaude/detail.cfm?mdrfoi__id=5851977
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« Reply #412 on: May 08, 2019, 10:19:39 AM »

Model Number 303-20
Device Problem Mechanical Problem
Event Date 04/07/2017
Event Type  Malfunction   
Event Description
It was reported that a lead was identified with a misshaped helix out of the box. The helix was reportedly not lined up. The lead was not implanted in the patient and a replacement lead was used in its place. A review of the manufacturing record of the lead confirmed it had passed all quality inspections prior to release for distribution. The lead has been returned to the manufacturer, but analysis has not been completed to date.
 
Event Description
The returned lead assembly was analyzed in the product analysis lab where it was confirmed that the helices were misshapen. Visual analysis identified bends and creases on the positive and negative electrode ribbons. The positive ribbon was partially detached from the helical. No discontinuities were identified with the returned lead, no abrasions were noted, and no setscrew marks were observed, confirming that the lead had never been implanted. The misalignment of the helices as observed in the lab had no adverse effect on the lead's ability to perform as intended.

https://www.accessdata.fda.gov/scripts/cdrh/cfdocs/cfmaude/detail.cfm?mdrfoi__id=6529452
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« Reply #413 on: May 18, 2019, 12:44:15 AM »

Model Number 304-20
Device Problems Detachment Of Device Component; Fracture
Event Date 04/27/2017
Event Type  Malfunction   
Event Description
It was reported that a neurologist observed high impedance on a patient's device during a clinic visit. The neurologist reported that high impedance was not observed during the previous clinic visit (b)(6) prior. The patient's family also reported that she had fallen during her seizures. The patient was referred for surgery. No additional relevant information has been provided to date. No surgical intervention has occurred to date.
 
Event Description
The patient's father reported that the patient was experiencing an increase in seizures due to the high impedance. According to the patient's father, the surgeon believed that the lead may have become dislodged from the patient's vagus nerve. The patient underwent full revision surgery. The surgeon and company representative confirmed that the electrode had become dislodged from the nerve, but the surgeon did not know what caused the electrode to come off of the nerve. The explanted lead and generator were discarded and are unavailable for analysis. No additional relevant information has been received to date.

https://www.accessdata.fda.gov/scripts/cdrh/cfdocs/cfmaude/detail.cfm?mdrfoi__id=6586456
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« Reply #414 on: May 20, 2019, 09:16:26 PM »

Model Number 106
Device Problem Adverse Event Without Identified Device or Use Problem
Event Type  Malfunction   
Event Description
It was reported that the patient had three breakthrough seizures, but the physician had also stopped the patient's vimpat. Diagnostics were performed, which confirmed that the device was functioning properly. No further relevant information has been received to date.
 
Event Description
It was reported that the patient's tie-down was protruding at the neck incision. It was stated that the patient has not had efficacy possibly from the lead being placed too low also causing side effects. It was alleged that the patient started feeling a burning sensation and vibrating in the throat with auto-stimulation. It was thought that the increase in seizures could have caused the patient to have more autostimulations than usual, which caused the burning/vibrating in the neck area. The device was then disabled in may due to the burning sensation and vibrating in throat. No additional relevant information has been received to date.
 
Event Description
Additional information was received that the device was likely disabled around (b)(6) as the patient was seen in the emu at this time. No additional or relevant information has been received to date.
 
Event Description
Information was received indicating that the patient is scheduled for a full replacement. Surgery is likely but has not been completed to date. No additional or relevant information has been received to date.
 
Event Description
The patient underwent a full explant. It was stated that x-rays were reviewed and revealed that the device was too low and the electrodes did not appear even on the nerve the explanted devices have not been received for analysis to date. No additional or relevant information has been received to date.

https://www.accessdata.fda.gov/scripts/cdrh/cfdocs/cfmaude/detail.cfm?mdrfoi__id=6566145
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« Reply #415 on: June 01, 2019, 03:28:07 AM »

Model Number 103
Device Problem Adverse Event Without Identified Device or Use Problem
Event Date 06/22/2017
Event Type  Injury   
Event Description
It was reported to a company representative that a patient has requested to have her device removed due to pain at the generator site. She is diagnosed with mental health problems and the patient¿s physician believes the pain is mostly psychological. Additional relevant information has not been received to-date. No known surgery has occurred to-date.
 
Event Description
Follow-up from the company representative who spoke to the provider indicated that the patient also had pain in the neck from when her grandson had slapped her on the neck. The device was turned off for a couple of weeks and was turned back on with no discomfort and the problem was considered resolved.
 
Event Description
Follow-up from the provider indicated that the neck pain had resolved and the most recent diagnostics were okay.
 
Event Description
Further follow-up from the provider indicated that trauma to the neck has partially dislodged, damaged the electrode and was causing pain. Lead revision surgery occurred, and the explanted device has not been received by the manufacturer to-date.
 
Manufacturer Narrative
Event description, corrected data: it was inadvertently not provided on follow-up report #3 that the device had been received by the manufacturer.
 
Event Description
The explanted device was received by the manufacturer. Documentation received indicated that the patient felt a lead pulling sensation and then painful stimulation. Analysis is underway, but has not been completed to-date.
 
Manufacturer Narrative
Event description, corrected data: the results of product analysis for the returned generator were inadvertently not provided in follow-up report #4.
 
Event Description
Analysis was completed for the returned lead. The electrode array portion was not returned for analysis, and evaluation could not 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.

https://www.accessdata.fda.gov/scripts/cdrh/cfdocs/cfmaude/detail.cfm?mdrfoi__id=6727567
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« Reply #416 on: June 02, 2019, 01:05:46 AM »

Model Number 304-20
Device Problems Fracture; High impedance
Event Date 05/13/2017
Event Type  Malfunction   
Event Description
It was reported on (b)(6) 2017 that the patient had high impedance. Her device was disabled. Clinic notes reported that the patient felt that the magnet wasn't working as the magnet swipes didn't make her cough like typically had before. No known surgical intervention has occurred to date. No further relevant information has been received to date.
 
Event Description
The patient underwent full revision surgery due to the high impedance. During explant of the lead, the surgeon noted that the patient's lead was not attached to the vagus nerve. All parts of the lead were anterior to the carotid artery. The surgeon said that the electrodes were around 0. 5 inches away from the vagus nerve. The suspect device has not been received to date. No further relevant information has been received to date.
 
Event Description
The patient's lead and generator were received into product analysis. Pa was completed on the returned lead. The lead was returned in 3 portions without tie-downs. Set screw marks were observed on the lead pin, indicating that at one point in time, there was a good electromechanical connection between the lead and generator. The condition of the returned lead portions was consistent with those that typically exist following an explant procedure. No obvious anomalies were noted. Continuity checks of the returned lead portions were performed during the visual analysis, and no discontinuities were identified. Product analysis was completed on the returned generator. The generator was monitored in a simulated body-temperature environment for over 24 hours. The generator provided the expected output current for the entirety of the monitoring period. Various electrical loads were attached to the pulse generator and results of diagnostic tests demonstrated that accurate resistance measurements were obtained in all instances. The generator performed according to functional specifications with no anomalies found. The surgeon and the treating physician indicated that they didn't know what caused the patient's electrode to migrate off the nerve. The treating physician did not know of any trauma to the neck site. No further relevant information has been received to date.
 
Manufacturer Narrative
Supplemental mdr 1-- describe event or problem, corrected data:supplemental mdr 1 inadvertently reported that the suspect product hadn't been received instead of "the suspect lead and the generator were received and pending completion of product analysis. " supplemental mdr 1-- device available for evaluation?, corrected data: supplemental mdr 1 inadvertently reported that the patient's product had not been received. However, prior to submission the mdr the product was received on 08/31/2017. Supplemental mdr 2-- date received by manufacturer (mo/day/yr), corrected data: supplemental mdr 2 inadvertently reported 08/31/2017 as the aware date instead of 09/13/2017.

https://www.accessdata.fda.gov/scripts/cdrh/cfdocs/cfmaude/detail.cfm?mdrfoi__id=6694894
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« Reply #417 on: June 03, 2019, 04:41:34 AM »

Model Number 302-20
Device Problem Fracture
Event Date 05/09/2013
Event Type  Malfunction   
Event Description
Operative notes reported that the patient had a generator and lead replacement surgery performed on (b)(6) 2013 due to battery near end of life and a lead fracture. The notes stated that there was increased impedance. During surgery, the new generator was connected to the existing lead; however, the impedance remained high. Dense scar tissue was also noted during the surgery and as a result the electrodes could not be removed. The explant hospital does not return explanted products. No additional relevant information has been received to date.

https://www.accessdata.fda.gov/scripts/cdrh/cfdocs/cfmaude/detail.cfm?mdrfoi__id=6836852
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« Reply #418 on: June 03, 2019, 04:42:28 AM »

Device Problem High impedance
Event Date 07/27/2017
Event Type  Malfunction   
Event Description
It was reported by the patient's mother that the patient had a generator replacement surgery that was occurring due to battery depletion of the generator. During the surgery, it was stated that the surgeon felt he might have broken the lead. The patient's mother then stated that the lead issue could have started before the replacement surgery since the patient had not been able to feel magnet stimulation in a while. The lead was replaced due to the possible high impedance issue. The explanting facility historically does not return explanted devices, so product return is not expected. No additional relevant information has been received to date.
 
Event Description
Further information was received from the physician that there was no trauma that had occurred for the patient before hand that could have led to the lead break. The surgeon also stated that he was not aware of any high impedance being observed during pre-op diagnostics. The cause of the lead break was stated to be that it "was kinked and cracked when we exposed/explanted it. " it is unclear if the damage was observed upon exposing the lead or caused by the exposing of the lead. Further inquiry was done with the neurologist who stated that he had not heard about a report of the magnet not working for the patient from the patient or the mother.
 
Event Description
It was reported by the physician that he believed that the patient's leads were out of position and that the patient was not actually receiving stimulation. It was determined that this was a reference to the vns electrodes. Follow up with the surgeon revealed that the electrodes were found to be attached to the patient's vagus nerve in the expected manner at the replacement surgery. The surgeon stated that the cause of the lead failure was the crack in the lead near the generator.

https://www.accessdata.fda.gov/scripts/cdrh/cfdocs/cfmaude/detail.cfm?mdrfoi__id=6822941
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« Reply #419 on: June 05, 2019, 12:47:28 AM »

Model Number 304-20
Device Problem Mechanical Problem
Event Date 07/07/2017
Event Type  Malfunction   
Event Description
It was reported that during a full vns revision surgery that the surgeon did not like the way the lead manipulated when he was attempting to implant it. Therefore, a second lead was used in its place and implanted without issue. Follow up with the company representative revealed that the surgeon was unable to get one of the electrode coils wrapped around the nerve and asked for a second lead. A review of device history records was performed and revealed that the lead passed quality control inspection prior to distribution. The lead was received by the manufacturer and is pending product analysis. No additional data has been received to date.
 
Event Description
Follow up with the surgeon revealed that the lead had been pulled taut in order reduce redundancy and fractured approximately 5 cm from the connector to the pulse generator. Product analysis was completed on the lead. No abnormalities were noted on the lead flexibility. The lead assembled was returned for analysis in one piece. The outer silicone tubing had punctured openings. Both the closest and furthest electrodes from the bifurcation are damaged, showing bends on the electrode ribbon and partial detachment of the electrode ribbon from the silicone helix with the silicone helices partially losing their helical shape. The observed damage to the closest and furthest electrodes from the bifurcation was most likely manipulation of the lead not consistent with labeling. Set-screw marks were seen on the connector pin, which indicates that proper contact was present at one point. A region with an opaque appearance was noted on the connector ring surface. No obvious pitting was noted at the region. Scratches on the connector ring likely caused by the canted spring in the header during lead pin insertion was observed. No anomalies were noted at the anchor tether. However, the positive coil was kinked at ¿0. 2 cm and the negative coil was kinked at ¿1. 2 cm past the anchor tether. No discontinuities were identified. Based on the appearance of the returned lead assembly, it is believed that the identified kinks and outer tubing punctured openings and electrode damage were most likely caused during the implant procedure.

https://www.accessdata.fda.gov/scripts/cdrh/cfdocs/cfmaude/detail.cfm?mdrfoi__id=6766837
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