It was reported that the patient had vns explant in 2006 due to cardiac episodes and painful stimulation.The patient had previously had generator replacement on (b)(6) 2006.Review of the generator programming history revealed that the device was programed off on (b)(6) 2007.The explant therefore occurred sometime after that time.The patient had vns re-implant surgery on (b)(6) 2014.During surgery, the surgeon noted that the old lead electrodes were inverted on the vagus nerve (with the positive and negative electrodes inverted).It was reported that in 2005, the patient had a cardiac episode and was hospitalized for bradycardia.Additionally, the patient had painful stimulation.As a result, the device was turned off, and the generator and a portion of the lead in the chest area was explanted.Review of programming history in-house reveals the device was programmed off on (b)(6) 2007.Follow-up with the patient's treating neurologist revealed that there is only limited information regarding the events, as the patient was treated by a different physician at the practice at the time of the events and that physician no longer works at the practice.The currently treating physician's recollection is that there were "big problems" with getting the patient regulated which would be explained by the inverted electrodes, per the physician.The explanted portion of the lead from surgery on (b)(6) 2014 was received by the manufacturer for analysis.Note that a large portion of the lead assembly (body); including the connector pin / boot section with model and serial number tag and the electrodes was not returned; therefore it was not possible to verify the model and serial number during this analysis and a complete evaluation could not be performed on the entire lead product.The condition of the returned lead portions is consistent with conditions that typically exist following an explant procedure.No obvious anomalies were noted.Continuity checks of the returned lead portions were performed, during the visual analysis, and no discontinuities were identified.Based on the findings in the product analysis lab, there is no evidence to suggest discontinuity in the returned portion of the device which may have contributed to the stated allegations.Additionally for the explanted generator on (b)(6) 2006, analysis was completed.Based on the battery life analysis, the pulse generator approached a normal end of life condition.In addition, the pulse generator was operating at an increased duty cycle (71%) and, as defined in the physician¿s manual, this will deplete the battery faster than a low duty cycle; this may have been a contributing factor.The reported condition of erratic stimulation at that time was not verified in the laboratory.Delivered generator output across an electrical load confirmed a steady output voltage consistent with programmed parameter settings.There were no signs of variation in the output signal.The pulse generator would not interrogate, therefore was opened.The measured battery voltage was below the low battery operation level specified for the pulse generator, which indicates that the pulse generator had reached the end of life.These measurement in the lab demonstrate appropriate current consumption for the device, resulting in normal battery depletion.No performance anomalies were noted.
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