Model Number 302-20 |
Device Problem
High impedance (1291)
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Patient Problem
Seizures (2063)
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Event Date 03/06/2014 |
Event Type
malfunction
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Event Description
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It was reported that the vns patient¿s device was tested and diagnostic results revealed high lead impedance (impedance value >= 10,000 ohms).The patient¿s device was subsequently disabled.The patient had been experiencing an increase in seizures.The patient had multiple seizure types and all have increased.X-rays were taken and were reported to be unremarkable.X-rays were provided to the manufacturer for evaluation.The generator appears in the upper left chest in a normal placement.The filter feed-through wires appeared to be intact.The lead connector pins appeared to be fully inserted into the generator connector block.The electrodes appeared to be placed in normal arrangement.Based on the images provided, the cause of the high impedance cannot be determined.The entire lead was not visible on x-rays and therefore continuity in the portions of the lead that were not able to be assessed cannot be confirmed.Review of the available programming and diagnostic history showed normal diagnostic results through (b)(6) 2011.No known interventions have occurred to date.
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Event Description
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It was reported that the patient was scheduled for revision surgery.The patient underwent surgery on (b)(6) 2014.The explanted devices have not been received to date.
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Event Description
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The generator and lead were returned for analysis.Analysis is underway, but has not been completed to date.
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Event Description
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Additional information was received stating the vns patient was in the hospital when he began experiencing the reported increase in seizures, which was believed to be due to the lead fracture identified during analysis of the returned lead portion.
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Manufacturer Narrative
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Manufacturer reviewed x-rays of implanted device.Review of the available programming and diagnostic history.X-rays reviewed by manufacturer, no gross lead discontinuities visualized.Device failure is suspected, but did not cause or contribute to a death.
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Manufacturer Narrative
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Device manufacturing records were reviewed.Review of manufacturing records of the lead confirmed all quality tests were passed prior to distribution.
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Manufacturer Narrative
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Adverse event and/or product problem, corrected data: supplemental mdr #01 inadvertently did not update this field based on the additional information reported in the report.Outcomes attributed to adverse event, corrected data: supplemental mdr #01 inadvertently did not update this field as interventions had taken place.Additional information was received stating that the patient was also hospitalized.
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Manufacturer Narrative
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Device failure occurred, but did not cause or contribute to death.
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Event Description
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Analysis of the returned generator and lead was completed.The generator analysis will be reported in the next quarterly remedial action exemption report.The lead assembly has dried remnants of what appear 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.Incisions in the silicone tubing were necessary to perform proper inspection of the lead coils.A break was identified in one of the lead coils.Abraded openings were noted in the outer silicone tubing resulting in a portion of the positive coil being exposed.Scanning electron microscopy images of the positive coil show that pitting or electro-etching conditions have occurred at the exposed portion.Scanning electron microscopy images of the broken coil (coil 1) suggest a stress-induced fracture (fatigue) on at least two strands of the quadfilar coil as well as pitting or electro-etching conditions at the break location.Due to pitting and mechanical distortion (smoothed surfaces) the fracture mechanism of the other strands cannot be determined.Also, the broken coil shows what appear to be superficial voids in the vicinity broken coil wires at the mate end.No obvious adverse effect was identified on the device performance as a result of this condition.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 portions.
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Search Alerts/Recalls
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