Model Number 304-20 |
Device Problems
Corroded (1131); Fluid/Blood Leak (1250); Fracture (1260); Appropriate Term/Code Not Available (3191)
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Patient Problem
Seizures (2063)
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Event Date 04/01/2017 |
Event Type
malfunction
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Event Description
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It was reported that the patient was referred for a vns lead and generator replacement due to high impedance being observed.It was also noted that the patient was experiencing an increase in seizures.The physician reviewed x-rays of the patient and did not observe any obvious fractures however the patient¿s mother reported that the patient ¿messes with it all the time¿.X-rays were reviewed by the manufacturer and no obvious fractures were observed.Based on the ap view there appeared to potentially be a sharp angle in the region of the lead near the strain relief, however due to the quality of the image this could not be confirmed in the lateral view.Also due to the quality of the image provided the integrity of the lead near the lead pin could not be assessed.The connector pin did appear to be fully inserted into the generator and the generator¿s feed thru wires appeared intact.Based on the images provided no obvious source of the high impedance could be identified.It should be noted that the presence of a microfracture cannot be ruled out.It was later reported that the patient's family decided to disable the device before going forward with surgery.No surgical interventions are known to have occurred to date.No additional relevant information has been received to date.
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Event Description
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It was further clarified that the increase in seizures began approximately a month prior to the high impedance warning being observed.At a later follow-up visit it was reported the patient continued to be experiencing an elevated seizure frequency and the patient's parents decided to change the patient's prescription medications rather than replacing the vns device.
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Event Description
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Patient plans to undergo full revision surgery.No known surgical interventions have occurred to date.
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Event Description
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Patient underwent full revision surgery.The surgeon took out the old generator but in the process he bent the header too much to where it broke the seal on one side.The new generator was connected to the lead and system diagnostics was performed again resulting in high impedance and >10,000 ohms.The lead was thus taken out.The surgeon noted that the lead wire was completely separated from the silicone cover in the middle portion.The surgeon was able to remove one of the electrodes but the other two helices were left on the nerve.The new lead electrodes were placed above the old electrodes.The explanted devices have not been received to date.
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Event Description
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The explanted generator and lead were received.Various electrical loads were attached to the pulse generator and results of diagnostic tests demonstrate that accurate resistance measurements were obtained in all instances.Proper functionality of the pulse generator in its ability to provide appropriate programmed output currents was successfully verified in the pa lab.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.The battery, 3.011 volts , shows an ifi=no condition.The data in the generator memory locations revealed that 13.112% of the battery had been consumed.There were no performance or any other type of adverse conditions found with the pulse generator.Analysis of the lead is underway and has not been completed to date.In addition, the header was partially detached from the pulse generator case, which is not typical in a surgical procedure.It is very likely that the header was separated from the pulse generator case during or after the explant process.This is based on the location of the tool marks observed on the pulse generator case and header.Therefore, this observation/finding is not considered a device failure, but instead the result of extensive manipulation of the product during the explant process.This will not be coded as it is due to explant process.
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Event Description
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Break was identified in the positive coil at two locations.Also, abraded openings were identified in the positive and the negative lead coils.Scanning electron microscopy of the positive coil show that pitting or electro etching conditions occurred at the 1st break location.Also, scanning electron microscopy images of the positive coil breaks (break-1 mate end, and break-2 ends) showed what appears to be wear (flat surfaces) on the coil strands, resulting in a reduction of the diameter of the quadfilar coil strands up to the break point.The lead assembly has dried remnants of what appear to have once been body fluids inside the inner and the outer silicone tubing.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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