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dennis100
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« Reply #330 on: February 09, 2018, 11:14:34 AM »

Model Number 300-20
Device Problems Detachment of device component; No code available
Event Date 12/12/2017
Event Type Malfunction
Event Description
During a patient's prophylactic, full revision surgery, the positive and anchor electrodes were found to be detached from the vagus nerve and covered in scar tissue. Also, inadequate strain relief was found to have been provided by the original implanting surgeon. System diagnostics were performed before the revision surgery and indicated the device was functioning normally. Also, the patient's neurologist stated that no physical trauma or manipulation had occurred that may have caused the detachment. The lead has been returned and analysis is underway. No additional or relevant information has been received to date.

https://www.accessdata.fda.gov/scripts/cdrh/cfdocs/cfmaude/detail.cfm?mdrfoi__id=7168033
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dennis100
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« Reply #331 on: February 17, 2018, 04:32:01 AM »

Model Number 304-20
Event Date 11/22/2011
Event Type Malfunction
Event Description
It was reported on (b)(6) 2011 that a patient was in for an initial implant and during implant, high lead impedance readings were obtained when systems diagnostics were performed. The diagnostics were performed twice and both resulted in high lead impedance. The surgeon backed out the setscrew and connected the generator to the test resistor to perform generator diagnostics which resulted in ok/ok/4000 ohms/ifi no. The lead pin was re-inserted and confirmed to be fully inserted past the connector blocks. The setscrew was tightened back and systems diagnostics were performed again which resulted in limit/high/10,000 ohms/ifi=no. The surgeon then replaced the lead and diagnostics were repeated which gave acceptable results (specific results not provided). The explanted lead has been returned to the manufacturer and is currently pending product analysis.

Manufacturer Narrative

Event Description
Product analysis has been completed on the returned lead. The entire lead was returned to the manufacturer. During the analysis, a cut was identified in the positive coil at the end of the electrode bifurcation. Based on the appearance of the lead, it is believed that this condition occurred during the attempted implant procedure. Other than the above mentioned observations and conditions that exist after manipulation and attempted implant of the lead, no additional anomalies were identified in the returned lead.

https://www.accessdata.fda.gov/scripts/cdrh/cfdocs/cfmaude/detail.cfm?mdrfoi__id=2381294
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dennis100
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« Reply #332 on: February 28, 2018, 02:03:37 AM »

Model Number 302-20
Event Date 05/14/2014
Event Type Malfunction
Event Description
It was reported that the vns patient¿s device was tested during an office visit on (b)(6) 2014 and diagnostic results showed high lead impedance (dc dc ¿ 7). The patient¿s device settings were increased during the office visit. Patient manipulation or trauma is not believed to have caused or contributed to the high impedance. X-rays dated (b)(6) 2014 were provided to the manufacturer for further review. The generator appears in the left chest in a normal placement. The filter feed-through wires appear to be intact. The lead connector pin appears fully inserted into the generator connector block. The electrodes appeared to be placed in an abnormal arrangement. The second electrode appears to either be placed upside down or possibly has come off the nerve. Part of the lead was 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. Based on the images provided, the cause of the high lead impedance may be due to detachment of the second electrode but no definitive conclusions can be made. Further follow-up revealed that the patient¿s device had been disabled and the patient still had good seizure control. Review of the available programming and diagnostic history showed normal diagnostic results through (b)(6) 2011. No known surgical interventions have occurred to date.

Manufacturer Narrative
Manufacturer reviewed x-rays of implanted device. Device manufacturing records and available programming and diagnostic history were reviewed. X-rays reviewed by manufacturer, no gross lead discontinuities visualized. Review of manufacturing records confirmed that the lead passed all functional tests prior to distribution. Device failure is suspected, but did not cause or contribute to a death or serious injury.

https://www.accessdata.fda.gov/scripts/cdrh/cfdocs/cfmaude/detail.cfm?mdrfoi__id=3857029
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dennis100
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« Reply #333 on: March 04, 2018, 01:24:37 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 #334 on: March 05, 2018, 02:18:36 AM »

Model Number 302-20
Event Date 04/02/2012
Event Type Malfunction
Manufacturer Narrative
Device failure occurred, but did not cause or contribute to a death or serious injury.

Event Description
On (b)(6) 2012, a vns implanting surgeon's nurse stated that the vns patient had their leads replaced on (b)(6) 2012, due to the surgeon observing electrode damage when replacing the generator due to end of service. When the new generator had been implanted, diagnostics performed showed high impedance and the electrodes appeared to be damaged; therefore the leads were replaced. The explanted lead and generator were returned to the manufacturer for product analysis on (b)(6) 2012, that has not yet been completed. The surgeon later reported that the generator had been at end of service so the lead impedance could not be tested prior to surgery. Surgery was the first time the high impedance we observed. The surgeon was unsure if x-rays were taken prior to surgery or if patient manipulation or trauma occurred that is believed to have caused or contributed to the high impedance. A battery life calculation was performed with the patient's programming history which showed negative years until the elective replacement indicator is flagged as yes.

Event Description
Additional information was received on (b)(6) 2012, when product analysis was completed on the explanted generator. The generator was found to be at end of service and was determined to be the result of normal battery depletion. The depletion was an expected event as determined by battery life calculation and battery voltage measurement. The module performed according to functional specifications and there was no condition noted during the product analysis evaluation that would suggest any anomaly with the device. Product analysis on the lead was completed on (b)(6) 2012. The electrodes were not returned for analysis; therefore a complete evaluation could not be performed on the entire lead product. During the visual analysis a lead break was observed. Scanning electron microscopy was performed and identified the areas as having evidence of being worn to the point of fracture with flat spots on the coil surface, no pitting and residual material. It is unknown if the breaks occurred while stimulation was present due to the absence of metal pitting on the broken coil wire surfaces. The abraded openings found on the outer silicone tubing, most likely provided the leakage path for what appeared to be remnants of dried body fluids found inside the outer silicone tubing. The abraded opening found on the connector ring inner silicone tubing, most likely provided the leakage path for what appeared to be remnants of dried body fluids found inside the inner silicone tubing. There was no obvious path found for the fluid ingress observed inside the connector pin inner silicone tubing. With the exception of the observed discontinuity, the condition of the returned lead portion 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. Continuity checks of the returned lead portion were performed, during the visual analysis, and no other discontinuities were identified.

Manufacturer Narrative
(b)(4).

Manufacturer Narrative
Analysis of programming history. 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=2572452
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dennis100
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« Reply #335 on: March 08, 2018, 09:42:10 AM »

Event Date 06/03/2011
Event Type Injury
Event Description
It was reported that the vns patient has been experiencing "vocal cord issues" since implant. The patient was seen by an ent physician who indicated that he believes the lead was implanted too close to the vocal cords. It was also noted that the patient has not seen much efficacy since implant. The patient was reportedly going to see the implanting surgeon for further evaluation however the surgeon's office indicated that the patient has not been seen or made an appointment. Attempts for further information from the neurologist's office have been unsuccessful to date. Attempts for the product information were unsuccessful.

Event Description
Additional information was received indicating the patient's vocal cord issue has resolved.

Event Description
On (b)(6) 2012, additional information was received indicated that the patient had hoarseness and awakening at night with vns stimulation noted in (b)(6) 2011. It was confirmed that vocal cord issues were related to electrodes being placed too close to the larynx. No hoarseness was noted (b)(6) 2011. On (b)(6) 2011, the hoarseness was intermittent but then constant on in (b)(6) 2011. A note indicated the hoarseness appeared to have resolved following the thyroidectomy. The thyroid issues were not believed to be related to vns.

Manufacturer Narrative

Manufacturer Narrative
Type of report, corrected data: initial report inadvertently did not indicate "30-day. ".

Manufacturer Narrative
Event date, corrected data: previously submitted mdr indicated an incorrect event date. The patient's physician believes that the vocal cord issues are related to the electrodes being placed too close to the larynx at the time of implant; therefore, the event date is the date of implant: (b)(6) 2011. This report is being submitted to correct this data.

https://www.accessdata.fda.gov/scripts/cdrh/cfdocs/cfmaude/detail.cfm?mdrfoi__id=2603575
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dennis100
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« Reply #336 on: March 12, 2018, 01:27:02 AM »

Device Problem Fracture
Event Date 02/07/2012
Event Type Malfunction
Event Description
Additional information was received on (b)(6) 2012, when product analysis was completed on the explanted generator. Bench interrogation/diagnostic test showed that the nearing end-of-service indictor (neos) was set to yes. Results of the bench diagnostic testing indicated the device was operating properly with neos yes. The data in the memory locations revealed that 100. 148% of the battery had been consumed. A comprehensive automated electrical evaluation showed that the pulse generator performed according to functional specifications, with the exception of the expected low battery voltage. The battery voltage value stored within the generator, 2. 171 volts, suggests an neos battery partially depleted condition. The electrical test results showed that the pulse generator module performed according to functional specifications. However, the measured 2. 285 battery voltage (generator module post open can) is lower than expected for the percentage of battery consumed value of 100. 148%. Further review revealed that the explanted generator was returned with the output current programmed to 3. 00 ma. The data from the generator shows a high impedance (22183 ohms) estimated occurrence on (b)(6) 2012 (explant (b)(6) 2012) and remained until received into decontamination on (b)(6) 2012 (generator output current programmed to 0. 0ma). The combination of a high impedance value and output current setting required a "vboost" compliance voltage that exceed the maximum compliance voltage capability for the device (>10. 5 v). Longevity estimates are not guaranteed at compliance voltages greater than 10. 5v. In this situation a significant amount of additional current consumption exists, based on the need for a component to remain on (asic remains in a trickle charge state) in order to support the higher electrical load demand. This condition contributes to the disparity between the battery voltage and percent battery capacity that has been consumed, based on the device's internal eos projection system. Other than the noted error, there were no performance or any other type of adverse conditions found with the pulse generator.

Event Description
On (b)(6), 2012 it was discovered that the vns patient also underwent prophylactic generator replacement on (b)(6), 2012. The explanted generator was returned for product analysis on (b)(6), 2012 but the leads were not returned. Product analysis is still underway and has not yet been completed.

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

Event Description
On (b)(6) 2015 during review of the patient's programming history it was found that the patient has had high impedance since the generator was implanted on (b)(6) 2012. There was programming history through (b)(6) 2012 indicating that the generator was not replaced on (b)(6) 2012 like previously reported. It was also reported that the patient's current generator was implanted on (b)(6) 2012. The patient currently has high impedance; therefore it is unclear if the patient did in fact have a lead replacement on (b)(6) 2012 as planned since there was no confirmation indicating that the lead was replaced. Good faith attempts for further information regarding whether the patient did have a lead revision on (b)(6) 2012 were made but were unsuccessful.

Event Description
On (b)(6) 2012 a nurse reported that the vns patient was scheduled for a chest and neck x-ray tomorrow as the neurologist thinks there may be an issue with lead breakage or lead not functioning properly. She stated that a copy of the x-rays would be sent to the manufacturer for review. Attempts for further information have been made but no additional information has been received from the physician. The manufacturer's consultant stated that the epileptologists are not forthcoming with information due to hippa. The patient's implanted product information has been requested from the implanting hospital, but the hospital stated that they would not provide that information without patient consent or attorney request. Since the manufacturer does not have either of these, the product information cannot be obtained. A/p and lateral views of the neck and chest were received and reviewed on (b)(6) 2012. Due to x-ray films provided, it could not be confirmed that the lead pin is fully inserted into the generator connector block. There appeared to be lead behind the generator, so continuity in that portion of the lead could not be fully assessed. No lead discontinuities were seen in the visible portions of the lead. The electrodes could be visualized in the neck, but they appeared to be at an angle to one another. Based on the images provided and given the angle of the electrodes, proper alignment of the electrodes on the nerve could not be confirmed. However, it is noted that there are two previous sets of electrodes present that do not appear to be parallel in relation to the current electrodes. Therefore, the angle of the electrodes may be due to the patient's anatomy, and the electrodes may in fact be placed on the nerve. Based on the x-ray film images provided, no clear cause for the high lead impedance could be found, however it is possible that the lead pin is not fully inserted, there is an unpronounced break in the lead, or a micro-fracture that cannot be seen on the x-ray films provided. In addition, improper alignment of the electrode(s) could not be ruled out as a contributory cause. The patient underwent lead revision surgery on (b)(6) 2012. Attempts for product return will be made.

https://www.accessdata.fda.gov/scripts/cdrh/cfdocs/cfmaude/detail.cfm?mdrfoi__id=2638515
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dennis100
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« Reply #337 on: March 12, 2018, 01:29:47 AM »

Event Date 08/22/2011
Event Type Malfunction
Manufacturer Narrative
Device failure is suspected but did not cause or contribute to a death or serious injury.

Event Description
During the periodic programming history review, it was noted that high impedance was observed on (b)(6) 2011. No further diagnostics are available. Follow up with the physician confirmed that the replacement surgery which occurred on (b)(6) 2012 was for high impedance. The physician could not recall if the vns device was disabled to 0ma after the high lead impedance was observed and was uncertain if x-rays were taken as the "patient ran away for almost one year. " there was no manipulation or trauma that occurred which is believed to have caused or contributed to the lead fracture.

Manufacturer Narrative
Corrected data: additional information was received which indicates the date reported on the initial mdr was incorrect. Analysis of programming history.

Event Description
On (b)(6) 2012, a surgeon reported that he was performed a battery replacement. Prior to surgery there was no evidence of high impedance; however, after a new generator was connected, high impedance was seen. The surgeon stated that he removed the pin and then reinserted; however, a dcdc code of 7 was reported (the actual evidence of high impedance is unknown as the generator that was connected would provide an impedance value in ohms, not a dcdc code). The surgeon stated that there he was in the process of revising the lead. The physician phoned in a second time and reported that high impedance was seen after the lead was revised. The surgeon replaced the generator that had been implanted earlier in the surgery and reported that everything was okay. No additional information was provided regarding why the high impedance was attributed to the new generator. The high impedance on the generator is captured in mfr report #1644487-2012-01872. Follow up with the surgeon's office on (b)(6) 2012, revealed that no additional information was available; however, operative notes would be provided. Pre-operative diagnoses indicated there was a malfunction of the neurologic device. Postoperative diagnoses also indicated a malfunction of the neurologic device. Operative findings indicated high lead impedance, fracture of the rostral most electrode, and a defective model 103 generator. The patient's settings were provided. It was stated that as the battery had reported a near end of life message, the patient opted for revision. During the procedure, electrocautery was used to reach the generator. The generator was removed and a new generator (m103) was connected. High lead impedance was seen. The old generator was reattached and high impedance was seen again, reportedly consistent with an electrode malfunction. The incision at the neck was reopened, and the electrode wire was found to be fractured at two points: after the level of bifurcation of the electrode wire into two single wires and the wires. The wire was reportedly heavily scarred in. The electrode coils were removed, and a new electrode was placed. The new generator was attached to the new electrode, and high lead impedance was seen again. The notes stated that, at this point, the patient was clear with all scar tissue having been resected; therefore, "the problem at this point laid in the generator". A second new generator was programmed to the patient's pre-implant settings and replaced in the anterior chest wall pocket. The electrode distal to the electrode coils was secured was plastic pledgets and 3-0 silk suture. Care was taken to maintain a generous strain relief loop and to avoid any tension or kinks in the electrode within the neck. Attempts for product return have been unsuccessful as the facility only releases explanted devices to patients. Attempts for product information have been unsuccessful.

https://www.accessdata.fda.gov/scripts/cdrh/cfdocs/cfmaude/detail.cfm?mdrfoi__id=2669008
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« Reply #338 on: March 15, 2018, 01:52:32 AM »

Model Number 302-20
Event Date 08/29/2012
Event Type Malfunction
Manufacturer Narrative
Analysis of programming history. Device failure is suspected but did not cause or contribute to a death or serious injury.

Event Description
On (b)(6) 2012, it was reported that the patient was experiencing painful stimulation in the neck area for the last day or so. X-rays were taken, and no lead issue was seen. The x-rays would not be sent to the manufacturer for review. High lead impedance was seen the day before and the patient's device was disabled late on (b)(6) 2012, or early on (b)(6) 2012. The patient underwent surgical consult. The patient was reported to have been seizure-free for three years, and there was no reported increase in seizures. There was no known trauma. On (b)(6) 2012, the patient reported that, during interrogation earlier in the day, an error message popped up which said that her leads are detached or there is tissue build up. The patient stated that x-rays were taken but did not show any detachment. The patient stated that the device was programmed off and that she was referred for lead replacement due to the detachment issue. The patient stated that there had been no trauma or manipulation that she was aware of; however, she occasionally lifted heavy things. The generator and lead were replaced on (b)(6) 2012. X-rays were observed prior to surgery and a definitive lead break was observed in the lead just above the bifurcation. During surgery, it was noticed that the electrode coils appeared to be pulling off of the nerve but that they were scarred in tightly. The patient's generator was replaced prophylactically. The lead and generator were returned on (b)(4) 2012 and are currently undergoing product analysis. A battery life calculation on (b)(4) 2012, resulted in 7. 67 years to neos.

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

Event Description
Product analysis for the explanted generator was approved on (b)(6) 2012. The device performed according to functional specifications. Analysis of the generator in the (b)(4) lab concluded that no abnormal performance or any other type of adverse condition was found. Product analysis for the explanted lead was approved on (b)(6) 2012. The electrodes of the lead were not returned for product analysis. Setscrew marks on the connector pin provided evidence that proper contact between the setscrew and lead pin existed at least once. Abrasions were identified on the outer silicone tubing at multiple locations and on the connector boot. The outer silicone tubing had cuts at several locations. Some cuts did reach the inner silicone tubing. Abrasions were identified on the silicone tubing of the lead coils. The silicone tubing of the positive coil appears to be abraded and open in the vicinity of the coil end. It is believed that this condition could potentially contribute to the patient "pain" allegation. However, the exact impact of this condition and when it occurred is unknown. Scanning electron microscopy images of the positive coil show that pitting or electro-etching conditions have occurred in the vicinity of the coil cut end. 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 within the returned lead portion.

https://www.accessdata.fda.gov/scripts/cdrh/cfdocs/cfmaude/detail.cfm?mdrfoi__id=2758863
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« Reply #339 on: March 20, 2018, 01:18:02 AM »

Model Number 300-20
Event Date 09/10/2012
Event Type Malfunction
Event Description
The patient's device was programmed off on (b)(6) 2014. No known surgical interventions have been performed to date.

Event Description
It was reported that the patient will not undergo lead replacement. It was reported that the decision to lead the vns off was made. It is believed that the patient may not be a good candidate for lead replacement surgery. No additional relevant information has been received to date.

Event Description
Attempts for additional information from the treating neurologist have been unsuccessful to date. While revision is likely it has not occurred to date as per the surgeon, the decision for replacement has been left up to the patient's parents.

Event Description
A review of programming history, available in house revealed that during initial implant, two system diagnostic tests were run; the first resulting in high impedance while the second resulted in a dc/dc code of 0. It is unclear at this time if a lead fracture was present at the time of implant. Additionally programming history was provided by the physician who indicated that on (b)(6) 2012, prior to the generator replacement, the diagnostics showed a dc/dc of 0 on a system test and a dc/dc 1 on a normal mode test. On (b)(6) 2012 the impedance was a dc/dc equal to 7. It was noted by the physician that no trauma has been reported.

Event Description
Further follow-up revealed that the patient met with the surgeon and they are worried about how the patient will tolerate surgery. For this reason, the surgery has been placed on hold for now. The patient's family believes that the magnet does shorten and stop the patient's seizures.

Event Description
It was reported that the patient was scheduled for surgical consult. Surgery is likely, but has not occurred to date.

Event Description
The patient's neurologist reported that high lead impedance was found on the patient's system and normal diagnostic tests. Ap and lateral x-rays of the chest and neck were taken on (b)(6) 2012 and sent to the company for review. The generator was seen in the left chest. The filter feedthru wires were intact and the lead pins could be seen past the connector blocks indicating that they were fully inserted into the generator. A portion of the lead appeared to be located behind the generator and could not be assessed. There appeared to be a suspect area located in the coiled lead near the generator. It was possible that a break occurred in this area; however, due to the contrast and image quality of the x-rays provided, a break could not be confirmed. The electrodes were observed in the neck, but they did not appear to be aligned. In the images provided it does not appear that the anchor tether is on the nerve. The lead was seen routed down towards the generator and the lead wires appear intact at the connector pins. Based on the x-ray images provided, the cause of the high impedance cannot be determined. However, the suspect area identified in the lead or the improperly aligned electrodes may be contributing factors. The presence of micro-fractures in the lead or fractures in the portion of the lead that could not be assessed cannot be ruled out.

Manufacturer Narrative
Analysis of programming history.

Manufacturer Narrative
Date received by manufacturer; corrected data: the information reported on supplemental mfr. Report #3 should have been (b)(4) 2013 rather than (b)(4) 2013.

Manufacturer Narrative
Manufacturer reviewed x-rays of implanted device. Review of x-rays by manufacturer revealed a suspected lead break; however, due to the image quality and lack of contrast, this could not be confirmed. Device failure suspected to have occured, but cannot be confirmed due to image quality and lack of contrast. Suspected device failure did not cause or contribute to a death or suspected injury.

https://www.accessdata.fda.gov/scripts/cdrh/cfdocs/cfmaude/detail.cfm?mdrfoi__id=2777500
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« Reply #340 on: March 31, 2018, 01:07:20 AM »

Model Number 300-20
Event Date 11/23/2011
Event Type Malfunction
Event Description
It was reported to our country representative in france that there was a vns patient with high lead impedance on a system diagnostic test, dcdc 7. No trauma previously reported and surgery will be planned. X-rays received for review. The generator is placed in a normal position in the upper left chest. The filter feed-through wires appeared to be intact. The lead connector pins appeared to be fully inserted. The lead wires at the connector pin appeared to be intact. The electrodes appeared to be broken and not fully attached to the vagus nerve. No strain relief-loop or bend was viewed. No tie-down was viewed either. Per labeling, a strain relief bend should be placed starting 3cm from the anchor tether and should be secured with a tie-down parallel to the anchor tether. A large loop should then be formed and secured with an additional tie-down to allow for full neck movement in all directions. Portions of the lead appeared to be behind the generator and could not be fully assessed. No acute angles or lead breaks were found. The lead body follows a straight line below the electrodes and then appears to be wound in loops around the placement of the generator. Based on the x-rays images, the reported high impedance is caused by the broken/detached electrodes.

Event Description
Additional information was received that diagnostics in (b)(6) 2011 were within normal limits. No manipulation of the vns system by the patient is suspected. No surgery is planned.

Manufacturer Narrative
Manufacturer reviewed x-rays of implanted device. X-rays reviewed by the manufacturer and a lead discontinuities was visualized. Device malfunction 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=2858611
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« Reply #341 on: April 03, 2018, 12:42:21 AM »

Model Number 302-20
Event Date 12/20/2012
Event Type  Malfunction   
Manufacturer Narrative
Serial #, lot #, expiration date: corrected data: previously submitted mdr provided incorrect lead product information. This report is being sent to correct this information. Date of implant, corrected data: previously submitted mdr provided incorrect lead product information. This report is being sent to correct this information. Device manufacture date, corrected data: previously submitted mdr provided incorrect lead product information. This report is being sent to correct this information.
 
Event Description
On (b)(6) 2013, this patient underwent lead revision. The explanted lead was returned on (b)(6) 2013 and is currently undergoing product analysis.
 
Manufacturer Narrative
Device failure occurred but did not cause or contribute to a death or serious injury.
 
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.
 
Event Description
An analysis was performed on the returned lead portions, and the reported allegations of high impedance was confirmed. During the visual analysis of the returned portion, the (-) green electrode quadfilar coil appeared to be broken at the proximal end of the anchor tether. Scanning electron microscopy was performed on the connector end of the (-) green electrode quadfilar coil break and identified one of the broken coil strands as having evidence of a stress induced fracture (fatigue appearance) with mechanical and no pitting. Scanning electron microscopy was performed on the electrode (mating) end of the (-) green electrode quadfilar coil break and identified one of the broken coil strands as being pitted and mechanically damaged. The remaining broken coil strands were identified as being mechanically damaged which prevented identification of the coil fracture type and no pitting. Pitting was 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. 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. 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 other discontinuities were identified.
 
Event Description
Reporter indicated a patient had high lead impedance 10,000 ohms with vns diagnostics testing at an office visit. The vns was disabled. X-rays were reviewed by the manufacturer on (b)(6) 2013. No obvious lead breaks were observed. The lead pin is fully inserted into the generator header, ruling out a lead pin issue and making a lead fracture the more likely cause of the high lead impedance. The lead electrodes are situated in an unusual angle towards the general direction of where the vagus nerve is located, suggesting the electrodes may not be placed per labeling. Lead replacement surgery is planned, but has not occurred to date.

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« Reply #342 on: April 05, 2018, 12:49:21 AM »

Model Number 302-20
Event Date 07/11/2011
Event Type  Injury   
Manufacturer Narrative

Manufacturer Narrative
Correction: patient identifier was inadvertently reported incorrectly on the initial medwatch and has been corrected. (b)(4).
 
Event Description
It was reported by a neurologist that a vns patient experienced coughing, hoarseness, and difficulty swallowing after his vns settings were increased from. 75 ma to 1 ma. The treating physician indicated the patient then experienced vocal cord paralysis and the patient has not recovered. Moreover, the neurologist indicated that when the patient had vns explanted due to high impedance (mfr report # 1644487-2011-01816), the surgeon saw that the superior electrode had been pulled partially from the nerve and the tissue was scarred. The patient's mother indicated the patient did not have a physical injury that could have contributed to the event. At the moment, good faith attempts to obtain further information regarding the event have been unsuccessful to date.

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« Reply #343 on: April 06, 2018, 01:56:02 AM »

Model Number 102
Event Date 11/19/2012
Event Type  Injury   
Event Description
Additional information was received which indicates that the physician who reported the tests from the microbiology lab were negative was mistaken. It was found that there were, in fact, no tests performed. It was stated that the patient's primary vns treating physician has the most accurate information on the patient, which indicates that the patient has been pain free since (b)(6) 2013 and all tests have been cancelled. No additional information has been provided.
 
Manufacturer Narrative
Device manufacturing records were reviewed. Review of manufacturing records confirmed sterilization for the generator prior to distribution.
 
Event Description
On (b)(6) 2013 it was reported by the physician that the patient may have an infection at the generator site. However, follow up with the neurologist found that there is not much evidence to support an infection and that a scan is being performed simply to rule out all possibilities of one. It was originally reported that the patient was feeling continuous stimulation and shocks in the neck at the electrode site. However, the neurologist stated that it is unknown what the cause of the pain is and if there is a relation to vns. The neurologist performed diagnostic tests on the device which showed that it was within normal limits and stated that no trauma or patient manipulation had taken place which could have caused or contributed to the event. No medical interventions were taken or planned at this time. X-rays of the patient were taken, but no abnormalities were noted. A review of the x-rays by the manufacturer found no obvious lead discontinuities in the areas that could be assessed. The generator was seen in the left chest area in a normal orientation and the filter feedthru wires appeared intact. The lead pin could be seen past the second connector block indicating that it is fully inserted into the generator. Due to the image quality, it could not be assessed if the lead is intact at the connector pin. The lead was seen routed from the electrodes to the generator. A portion of the lead appeared to be behind the generator and could not be assessed. The electrodes were observed in the neck and appeared to be in proper alignment; however, the positive electrode appeared to be at a slightly different angle than the negative electrode. This could be due to the electrode beginning to come off or due to patient anatomy. No gross lead fractures or sharp bends were visualized. Follow up with the neurologist found that the patient felt the pain as a continuous sensation of electric shock over the left cervical thoracic region which persisted even when both the output current and magnet output current were set at 0ma. The device was turned off for 15 minutes to test if the pain continued without stimulation. The patient's settings were found to be output current = 1. 5ma, frequency = 30hz, pulsewidth = 500usec, on time = 30 sec, off time = 10 min, magnet current = 0ma, magnet on time = 30 sec, magnet pulsewidth = 500usec. Normal diagnostic results showed communication = ok, output current = ok, dcdc=2, eos = no. A system diagnostic test was not performed. An exploratory surgery is being considered to determine the cause; however, surgery has not been scheduled yet. Per the surgeon, if the exploratory surgery occurs it would be for patient comfort. No medical or surgical intervention has been planned or taken to preclude a serious injury. Attempts have been made for additional information; however, they have been unsuccessful. No additional information has been provided.
 
Event Description
Follow up with a physician on (b)(6) 2012 found that the results from the microbiology lab were negative. It was stated that the patient still feels pain on her chest so the surgeon will probably remove the device. However, follow up with the primary treating physician found that the patient was no longer feeling pain as of (b)(6) 2013 and that all tests have been cancelled. The primary treating physician stated that he never suspected an infection and that this hypothesis was evoked by the surgeon on (b)(6) 2013 but never proven. It was stated that the source of these symptoms are still unknown. No additional information has been provided.
 
Manufacturer Narrative
Name and address, corrected data: incorrect initial reporter listed in initial mdr inadvertantly.

https://www.accessdata.fda.gov/scripts/cdrh/cfdocs/cfmaude/detail.cfm?mdrfoi__id=2975611
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« Reply #344 on: April 08, 2018, 12:47:38 AM »

Model Number 302-20
Event Date 08/25/2006
Event Type  Injury   
Event Description
Reporter indicated that during a patient's vns generator replacement surgery due to end of service on (b)(6) 2006, it was noted by the surgeon that the lowest lead connection was off of the nerve, which was putting traction on the nerve. Releasing the tension moved the nerve back to a more normal position. The surgeon described the patient's tissue as "weakened", and that the tissues might be consistent with an underlying collagen vascular disorder. The patient's "tissue", specifically the fascia and collagenous tissues were described as weakened and lacking the usual texture that these tissues should demonstrate and it is suspected the patient has an underlying collagen vascular disorder. It is unclear if the possible collagen disorder caused the lead to migrate. No trauma occurred. The patient was also reported as experiencing neck pain at the time along with the lead migration.

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« Reply #345 on: April 14, 2018, 12:26:27 AM »

Model Number 303-20
Event Date 02/01/2013
Event Type  Malfunction   
Manufacturer Narrative
Manufacturer reviewed x-rays of implanted device. X-rays reviewed by the manufacturer, lead pin not fully inserted past the connector block of generator.
 
Manufacturer Narrative
Device failure is suspected, but did not cause or contribute to a serious injury.
 
Event Description
Reporter indicated intermittent high lead impedance was noted for a patient who recently had vns generator replacement on (b)(6) 2013. The patient had no known trauma. The patient is also experiencing painful stimulation at the electrode site in the neck. X-rays were reviewed by the manufacturer. The electrodes are visualized at approximately t1 and are in alignment; the electrodes are implanted lower than what is usually seen. The generator is implanted in the left axilla. This is much more lateral than what is normally seen. The view does not allow full assessment of the lead pin insertion. The lead wire is intact at the lead pin. The filter feedthroughs are intact. There is a small amount of lead behind the generator that cannot be assessed. The cause of the high lead impedance is unknown at this time, but may be due to inadequate pin insertion or a lead fracture. Attempts for additional information are in progress.
 
Event Description
Reporter indicated the patient had vns lead pin reinsertion surgery performed on (b)(6) 2013. After the lead pin was reinserted into the generator header, diagnostics were within normal limits (3218 ohms). No new devices were implanted.
 
Event Description
Manufacturer review of the device history records for the vns lead and generator confirmed both devices passed all final testing prior to distribution.
 
Event Description
Additional x-rays were reviewed by the manufacturer. The lead pin did not appear to be fully inserted. No additional anomalies were noted. The surgeon indicated he felt the lead pin had been fully inserted as two audible clicks were heard when tightening the setscrew. However, the possibility of a lead fracture may also exist. Reporter indicated the patient was also having increased seizures and that the plan of care is to have vns revision surgery; however, this has not occurred to date.

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« Reply #346 on: April 22, 2018, 12:46:10 AM »

Model Number 304-20
Event Date 04/29/2013
Event Type  Malfunction   
Event Description
On (b)(6) 2013, it was reported that high impedance was observed for this patient (impedance; 10. 000 ohms). The patient was recently implanted, and no trauma/manipulation was reported. The device was not disabled. X-rays were taken but have not been received. Attempts for additional information have been unsuccessful. Surgery is likely but has not taken place.
 
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.
 
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 the patient had generator and lead replacement and the explanted product were returned to the manufacturer for evaluation. When received, the ram and flash data were downloaded from the generator. The data in the diagaccumconsumed memory locations revealed that 3. 456% of the battery had been consumed. Visual examination showed tool marks on the pulse generator case and header most likely associated with manipulation of the device during the explant procedure. Burn marks were observed on the pulse generator case indicating that the pulse generator may have been exposed to an electro-cautery tool. The septum was not cored. No other surface abnormalities were noted on this device. An interrogation and system diagnostics test were performed, with a one inch spacer between the generator and the programming wand. Resulting status checks for; communication were ok, lead impedance and current delivered were normal for all diagnostic tests performed. The generator was subjected to and successfully completed a final electrical test. The generator is operating within specification. The pulse generator diagnostics were as expected for the programmed parameters. A comprehensive automated electrical evaluation showed that the pulse generator performed according to functional specifications. The battery, 2. 974 volts as measured shows a non-ifi condition. The data in the diagaccumconsumed memory locations revealed that 3. 456% of the battery had been consumed. There were no performance or any other type of adverse condition found with the pulse generator. The lead was returned for the allegation of explanted due to high lead break/high impedance. No obvious anomalies were noted. The condition of the returned lead portions is consistent with conditions that typically exist following an explant procedure. The lead assembly was returned in two portions and the tie downs were not returned. On the returned 4234mm portion, setscrew marks were observed on the connector pin, providing evidence of a proper mechanical contact between conductive surfaces of both the generator and connector pin. Continuity testing could not be performed during the decontamination procedure because the returned lead was not connected to a generator when received into pa. Incisions were made to allow for continuity checks. Abrasions were observed on the inner silicone tubes, but did not penetrate. Incision marks were observed on the inner silicone tubes and the marks penetrated the insulation and the quadfilar coils appeared to be kinked, in these areas. No discontinuities were identified during the continuity check. An analysis performed on the returned lead portions did not confirm the allegation. Based on the findings in the product analysis lab, there is no evidence to suggest a discontinuity in the returned portions of the device which may have contributed to the stated allegations of explanted due to lead break/high impedance.
 
Event Description
Clinic notes dated (b)(6) 2013 were received. The notes indicated that the patient was seen and complained of a vns system malfunction of high impedance. The patient felt he was not improving.
 
Event Description
X-rays were received on (b)(4) 2013. The generator was seen in the left chest area in normal orientation. The filter feedthru wires appear intact and the lead appears intact at the connector pin. The lead pin could not be seen past the second connector block indicating that it may not be fully inserted into the generator. The electrodes were observed in the neck, but do not appear to be in proper alignment. In the images it appears that the electrodes are placed in the opposite alignment with the positive electrode on the bottom, followed by the negative electrode on top. The lead is routed upwards from the electrodes then down toward the generator. No gross discontinuities or sharp angles were observed in the portion that could be assessed. Clinic notes dated (b)(6) 2013 indicated that the patient was seen for vns system malfunction of a high impedance error. The patient did not feel that he was improving, the patient¿s vns incisions were well-healed. Surgery is likely but has not taken place.

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« Reply #347 on: April 23, 2018, 12:36:54 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 #348 on: May 04, 2018, 12:43:45 AM »

Model Number 302-20
Device Problem Detachment of device component
Event Date 08/21/2010
Event Type  Malfunction   
Event Description
It was reported that the patient was undergoing generator replacement surgery when the surgeon identified abraded openings in the lead tubing (reported in mfr. Report #1644487-2018-00663), so a lead revision was then performed. It was then identified that there was no strain relief, and the electrodes were detached from the nerve. The surgeon and ear, nose, and throat specialist stated that the nerve was bubbled and severely scarred from the electrodes rubbing on it. The impedance was within normal limits prior to the surgery, which indicated that the electrodes were in contact with patient tissue while implanted. It was believed that the electrodes rubbed against the nerve after becoming detached, which caused the damage to the nerve. The lead was received by the manufacturer, and analysis was performed (reported in mfr. Report #1644487-2018-00663). However, the electrode portion of the lead was not returned, so no analysis could be performed on the portion of the lead relevant to this report. No further relevant information has been received to date.
 
Manufacturer Narrative
(b)(4).

https://www.accessdata.fda.gov/scripts/cdrh/cfdocs/cfmaude/detail.cfm?mdrfoi__id=7467612
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« Reply #349 on: May 04, 2018, 11:49:48 PM »

Model Number 303-20
Device Problem No Known Device Problem
Event Date 03/14/2018
Event Type  Injury   
Event Description
It was reported by the company representative that a surgeon was having difficulty placing the lead on the nerve. The surgeon wanted to use a clip on the electrode to secure it to surrounding soft tissue. The surgeon had claimed that the nerve looked ¿ragged¿ and was the reason the electrode was having difficulty staying in position. Additional relevant information has not been received to-date.

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« Reply #350 on: May 06, 2018, 01:16:14 AM »

Model Number 304-20
Device Problems Extrusion; Human-Device Interface Issue
Event Date 06/01/2013
Event Type  Injury   
Event Description
Patient will undergo exploratory surgery on (b)(6) 2015 to try to remove the object that is in his neck. The surgeon plans to remove the object and will not remove it if it is affecting a vein. No additional information has been received after the exploratory surgery.
 
Event Description
It was reported that the patient cut himself of the neck area (near the electrodes) while shaving a few weeks prior and that he has now developed an infection at the site. It was reported that the patient has a thin frame and that the electrodes are visible through the wound. It was reported that the wound was full of pus and was "looking bad". The surgeon prescribed antibiotics and has scheduled the patient for explant. The surgery was scheduled; however, no information has been received that the explant has occurred as scheduled.
 
Event Description
Further investigation revealed that the patient's generator and lead were explanted on (b)(6) 2013.
 
Event Description
It was reported on 06/22/2015 that this patient, who had his device explanted in 2013, went to the er and the xray showed a "square piece of metal" under the skin. The patient was under the impression that the entire device was explanted. It is unknown at this time of the piece of metal found was left over from the vns explant surgery or is unrelated. Attempts for additional relevant information have been unsuccessful to date.
 
Manufacturer Narrative
Device manufacturing records were reviewed. Review of manufacturing records confirmed sterilization for both the generator and lead prior to distribution.

https://www.accessdata.fda.gov/scripts/cdrh/cfdocs/cfmaude/detail.cfm?mdrfoi__id=3282396
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« Reply #351 on: May 12, 2018, 12:59:56 AM »

Model Number 302-20
Event Date 10/02/2013
Event Type  Malfunction   
Event Description
On (b)(6) 2013, it was reported that the patient had a full vns replacement due to the battery being at end of service and because the lead "didn't work either". Follow up with the physician found that the patient had the lead replaced due to high lead impedance observed during surgery. When the patient as opened up, it was found that the electrodes were originally placed on another nerve and not the vagus nerve. Instead, the electrodes were placed on the ansa cervicalis nerve, which is about one third of the size of the vagus nerve, per the surgeon. This led to the patient developing scarring around the nerve and electrodes, which is what the physician believes is the cause of the high impedance. However, as the patient reported some benefit from vns, the physician believes that some stimulation was being delivered. The lead appeared intact, per the physician, so the high impedance was attributed to the scarring. Review of the lead device history records confirmed all quality tests were passed prior to distribution. The explanted device was returned to the manufacturer and product analysis was performed. Product analysis of the lead found no product related anomalies. 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 typical wear and explant related observations, no anomalies were identified in the returned lead portion. Attempts were made for additional information; however, no additional information was provided.
 
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.

https://www.accessdata.fda.gov/scripts/cdrh/cfdocs/cfmaude/detail.cfm?mdrfoi__id=3443385

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« Reply #352 on: May 15, 2018, 07:53:22 AM »

Model Number 302-20
Event Date 01/01/2008
Event Type  Malfunction   
Manufacturer Narrative
Device failure is suspected, but did not cause or contribute to death or serious injury.
 
Event Description
It was reported to mfr that the vns pt was having surgery due to high lead impedance. X-rays were taken and reviewed prior to surgery and according to the surgeon they were inconclusive. During surgery, the surgeon noted a lead break "at the connector boot area. " the surgeon removed all but approx 2 cm of the lead. Additionally, the surgeon was not able to implant a new lead on the left vagus nerve as there was "not enough room on the nerve" due to scar tissue formed. A new generator was implanted but the lead was not replaced. Attempts to obtain add'l info and the explanted devices for analysis are underway.

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« Reply #353 on: May 15, 2018, 07:54:07 AM »

Model Number 302
Event Date 07/02/2015
Event Type  Malfunction   
Manufacturer Narrative

Event Description
During review of the in-house programming/diagnostic history database, it was observed that high impedance was observed at office visit on (b)(6) 2015. It is unknown if any patient manipulation or trauma occurred that could have caused or contributed to the high impedance reading. Further follow-up found that the patient had been referred for generator replacement surgery. At the time, the surgeon did not want to replace the lead because he was concerned that there may not be enough room on the nerve for a new lead. However it is unclear how the surgeon made this assessment. The generator was replaced on (b)(6) 2015 and the existing lead was connected to the new generator. Following generator replacement a system diagnostic test observed high lead impedance with the newly implanted generator. Programming history indicated that as of (b)(6) 2016 the high impedance had not resolved. The physician was notified of the high lead impedance and the manufacturer's recommendations for addressing high lead impedance events. It was then reported that since the high impedance was observed the non-verbal patient has been agitated and experiencing dysphagia, loss of appetite and trouble sleeping. The device was programmed off on (b)(6) 2016. Following device disablement the patient's behavior and symptoms improved however the patient was still not eating well and appeared to be fearful of food. Attempts to obtain additional information have been unsuccessful to date. It is not known if the lead has been replaced to date.
 
Event Description
The patient's mother provided an update on her daughter's condition since the device was disabled. She reported that prior to the device being disabled she had taped the magnet over the generator and the patient's behavioral issues improved. However when the mother went to place the magnet she accidentally swiped the magnet and activated a magnet stimulation. The patient reacted to "defend herself" and appeared to be in pain from the magnet swipe. She also reported that the patient had undergone a barium swallow test in (b)(6) 2016 which showed that the patient was suffering from muscle spasms. She was placed on prevacid in response to the muscle spasms. However since the vns device has been disabled the patient is no longer suffering from issues with swallowing. The patient is still exhibiting an aversion for eating however the mother believes this may be a defensive response from the previous issues that were caused with the high impedance. The patient had been previously placed on 4 different sleep medications however none of them improved her sleeping difficulties. The patient is still suffering from issues sleeping since the device has been disabled.

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« Reply #354 on: May 15, 2018, 07:54:47 AM »

Model Number 302-20
Event Date 06/25/2012
Event Type  Malfunction   
Event Description
It was reported that a vns patient had high lead impedance with a dcdc 7. The patient is having seizures which they think is from their vns not working. No x-rays have been ordered. The patient did not have any fall or injury preceding the event. The patient is referred for surgery (b)(6) 2012.
 
Manufacturer Narrative
Device malfunction occurred, but did not cause or contribute to a death.
 
Event Description
An analysis was performed on the returned lead portion. Note that the electrode section was not returned for analysis and therefore a complete evaluation could not be performed on the entire lead product. During the visual analysis the connector pin quadfilar coil appeared to be broken approximately 240mm (connector end) and 243mm (electrode mating end) from the end of the connector boot in the area of observed abraded openings. Visual analysis was performed and identified the areas as having extensive pitting which prevented identification of the coil fracture type and mechanical damage. It is believed that stimulation was present for a certain period of time as evidenced by the presence of metal pitting. What appeared to be remnants of dried body fluids and white deposits were observed inside the outer and connector pin inner silicone tubing, throughout the majority of the returned portion. The abraded openings found on the outer and connector pin inner silicone tubing, most likely provided the leakage path for what appeared to be remnants of dried body fluids / white deposits found inside the outer and inner silicone tubing. With the exception of the observed discontinuity, the condition of the returned lead portion 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. Continuity checks of the returned lead portion were performed, during the visual analysis, and no other discontinuities were identified.
 
Manufacturer Narrative
Device failure suspected, but did not cause or contribute to a death.
 
Event Description
The patient had surgery (b)(6) 2012. Our consultant attended the surgery reported that when the surgeon exposed the carotid sheath, he stated there was not enough room remaining on the vagus nerve to place another lead. For this reason, the lead was cut and the electrodes remain on the nerve. No new system was implanted. The explanted portions of the lead were not returned for analysis. Their explanted generator was returned for analysis. The generator performed according to functional specifications. During the product analysis there were no anomalies found with the pulse generator.

https://www.accessdata.fda.gov/scripts/cdrh/cfdocs/cfmaude/detail.cfm?mdrfoi__id=2664590
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dennis100
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« Reply #355 on: May 27, 2018, 12:08:26 AM »

Model Number 102
Event Date 03/05/2014
Event Type  Death   
Manufacturer Narrative

Event Description
It was reported that the patient passed away from an unknown reason. It was reported that the device was explanted and would be sent to manufacturer for analysis. The medical examiner indicated that the patient's vagus nerve was explanted with the lead attached to avoid damaging the lead electrodes. The relationship between vns and the death is known. The generator and lead were returned for analysis. The reason for explant was reported as sudden unexpected death with recent history of myocardial infarct (non-ischemic) and possible arrhythmia. The generator analysis was completed on (b)(6) 2014. 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. The lead analysis was completed on (b)(6) 2014. The slice marks found on the outer and inner silicone tubes most likely provided the leakage path for the dried remnants of what appeared to have once been body fluids found inside the outer and inner silicone tubes. The marks appeared to have been made by a sharp object which could have occurred during the explant procedure, however this cannot be confirmed. During the visual analysis the (+) white and (-) green electrodes appeared to be embedded in what appeared to be remnants of dried body tissue. This condition may have prevented the (+) white and (-) green electrode ribbons from coming in contact with the vagus nerve. With the exception of the observed tissue-covered (+) white and (-) green electrodes the condition of the returned lead portion 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. 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.

https://www.accessdata.fda.gov/scripts/cdrh/cfdocs/cfmaude/detail.cfm?mdrfoi__id=3738321
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dennis100
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« Reply #356 on: June 09, 2018, 01:32:11 AM »

Model Number 304-20
Device Problem No Known Device Problem
Event Date 04/14/2018
Event Type  Malfunction   
Event Description
It was reported that a vns patient was scheduled for generator replacement due to battery depletion. The communication was reported to be okay prior to generator replacement, but after the generator replacement high impedance was found. The surgeon found a broken electrode. A new electrode was installed, and the patient was in good condition with impedance measurements within normal limits of 1,416, 1,562, and 1,445 ohms. The explanted devices were received and analysis is underway, but has not been completed to-date. Additional relevant information has not been received to-date.

https://www.accessdata.fda.gov/scripts/cdrh/cfdocs/cfmaude/detail.cfm?mdrfoi__id=7500445

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dennis100
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« Reply #357 on: June 15, 2018, 01:13:33 AM »

Model Number 303-20
Device Problem No Known Device Problem
Event Date 08/09/2017
Event Type  Injury   
Event Description
Report was received that a patient started experiencing arrhythmia while under anesthesia. The patient was receiving a full revision surgery. After the new generator and lead were implanted, system diagnostics were run and showed high impedance (reported in mfr. Report #1644487-2017-04401). A second lead was tried but the surgeon had difficulty wrapping the electrodes around the nerve. The surgeon reported this was related to the vagus nerve being too big for the 2 mm lead used. This led to extended time under anesthesia. Due to this duration of surgery and the manipulation of the vagus nerve, the patient experienced arrhythmia. The anesthesiologist reportedly recommended that the surgery be terminated as a result. The generator was reportedly left implanted without any lead attached. Further information was received that the arrhythmia was not occurring with stimulation as it appeared about an hour after the last system diagnostic had been performed. It was also reported that the arrhythmia was benign. The lead passed all quality inspections prior to release for distribution. Device evaluation is not necessary due to the arrhythmia not being related to delivery of therapy. No further information has been received to date.
 
Manufacturer Narrative
Device evaluation not necessary due to the event not being related to delivery of therapy at all.

https://www.accessdata.fda.gov/scripts/cdrh/cfdocs/cfmaude/detail.cfm?mdrfoi__id=6844458
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dennis100
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« Reply #358 on: June 30, 2018, 02:36:09 AM »

Model Number 102
Event Date 01/18/2007
Event Type  Injury   
Event Description
Reporter indicated that a vns patient had bradycardia with vns stimulation. The vns was disabled on (b)96) 2007 and the bradycardia resolved. The vns has been disabled since this date, and will remain disabled at the reporter's discretion. The patient does not have a pre-vns history of bradycardia. Medication therapy will be utilized for the patient's seizure control. The bradycardia was felt to be due to the normal delivery of vns stimulation. It was not known if the patient had been referred to a cardiologist at the time the bradycardia occurred.
 
Event Description
Exploratory surgery for the patient to verify if the vns electrodes are aligned properly on the nerve is likely, but has not occurred to date. It is also possible a new vns lead and generator will be implanted.
 
Event Description
It was reported that the patient has been referred for generator and lead replacement. The physician believes that the electrodes were not placed correctly due to the patient suffering life-threatening bradycardia when initially implanted. No known surgical interventions have been performed to date.

https://www.accessdata.fda.gov/scripts/cdrh/cfdocs/cfmaude/detail.cfm?mdrfoi__id=2052578
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dennis100
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« Reply #359 on: July 03, 2018, 12:09:20 AM »

Model Number 304-20
Device Problems Detachment of device component; No Known Device Problem
Event Date 10/30/2015
Event Type  Injury   
Event Description
The patient had full revision surgery. The generator was not sutured to the fascia, but was merely buried in subcutaneous tissue, which allowed for generator migration. The generator not being secured and the possible relationship to the pain experienced at the chest will be reported together in mfr. Report #1644487-2018-00847 as these issues now appear to be separate from the events in this report. The tie-downs were not sutured in place, and the surgeon noted that the electrodes were not properly coiled around the nerve. The explanting facility discards of product, so no evaluation could be performed on the devices. No further relevant information has been received to date.
 
Event Description
It was reported that the patient was experiencing multiple adverse events. The patient felt throbbing pain in her left neck and significant pain/tenderness at the neck incision and up her neck to her ear for four days. She also reported that she could feel the "clamp" prominently under the incision when she touched her neck. The patient also felt painful stimulation for the past four days, and she had not felt stimulation up to that point. She had been having left ear pain/trouble hearing/feeling like her ear was "stopped up" for about four months, but the physicians did not identify any ear infections. The patient also felt pain in her chest, neck, and left shoulder for two to three days after her vns magnet was swiped. The patient had been feeling pain since she was implanted, but the pain had just recently gotten unbearable. The patient was taking pain medication four times a day, but that did not make the pain go away. The patient's ear hurt so badly that she could not let the wind hit it. The patient's treating physician believed that the surgeon had poor implant technique and the pain was related to the placement of the device. The physician did not know the cause of the pain during magnet swipes, and he didn't know if the hearing loss was related to vns or not. The patient was referred for surgery, and it was being done to preclude a serious injury as the patient was in excruciating pain that was getting worse. X-rays were ordered, but they have not been reviewed to date. No surgical intervention has occurred to date.

https://www.accessdata.fda.gov/scripts/cdrh/cfdocs/cfmaude/detail.cfm?mdrfoi__id=7373200
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