Model Number 302-20 |
Device Problem
High impedance (1291)
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Patient Problems
Seizures (2063); Therapeutic Response, Decreased (2271)
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Event Date 12/01/2013 |
Event Type
malfunction
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Event Description
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It was reported that device diagnostics resulted in high impedance (>10,000 ohms).It was reported that the diagnostics were within normal limits in (b)(6) 2013 and that the patient started to experienced an increase in seizures in (b)(6).The device was programmed off and the patient was sent for x-rays.It was reported that it is unsure if any trauma occurred that could have caused or contributed to the high impedance, but that the patient experiences drop attacks and the high impedance may be trauma related.It was reported that the seizures were back to pre-vns baseline frequency.The patient was referred to surgery.Surgeon noted that x-rays did not identify a clear lead break, but that the images would be sent to manufacturer for review.Review of x-rays did not identify any obvious discontinuities with the lead.Surgery is likely, but has not occurred to date.
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Event Description
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It was reported that the patient underwent generator and lead replacement.The explanted devices are expected to be returned to manufacturer for analysis, but have not been received to date.
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Event Description
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An implant card was received that corrected the date of explant.
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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.Device failure is suspected, but did not cause or contribute to a death or serious injury.
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Event Description
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Analysis of the returned generator was completed.Monitoring of the device output signal showed no signs of variation in the pulse generator¿s output signal and demonstrated that the device provided the expected level of output current.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.There were no performance or any other type of adverse conditions found with the pulse generator.
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Manufacturer Narrative
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Device failure occurred, but did not cause or contribute to a death.
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Event Description
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The generator and lead were received for analysis.Analysis of the lead was completed on 06/12/2014.The lead assembly was returned intact.During the visual analysis the (+) connector ring quadfilar coil appeared to be broken approximately 322mm from the end of the connector boot.Scanning electron microscopy was performed on the connector end of the (+) connector ring quadfilar coil break (found at 322mm) and identified the area as having extensive pitting which prevented identification of the coil fracture type with mechanical damage.Scanning electron microscopy was performed on the electrode (mating) end of the (+) connector ring quadfilar coil break (found at 322mm) and identified the area 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.What appeared to be white deposits were observed in various locations.Eds (energy dispersion spectroscopy - provides chemical or element identity/composition analysis) was performed and identified the deposit as containing silicon, phosphorus and calcium.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 portions were performed, during the visual analysis, and no other discontinuities were identified.Analysis of the generator is underway, but has not been completed to date.
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Search Alerts/Recalls
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