Pre-operative diagnostics performed prior to surgery for the generator migration identified high impedance (7335 ohms).Both the lead and generator were replaced.The generator and lead were received for analysis.Analysis of the lead was completed on 03/07/2016.Note that portions of the (+) white and (-) green electrode inner silicone tubes and quadfilar coils, anchor tether and the (-) green electrode were not returned for analysis; therefore a complete evaluation could not be performed on the entire lead product.During the visual analysis of the returned 230mm portion quadfilar coil 1 appeared to be broken approximately 21mm from the end of the electrode bifurcation.Scanning electron microscopy was performed and identified the area as having extensive pitting with mechanical damage which prevented identification of the coil fracture type.Pitting and residual material were 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.The abraded open / torn area found on the outer silicone tubing and the cut ends that were made during the explanted process, most likely provided the leakage path for the dried remnants of what appeared to have once been body fluids found inside the outer silicone tubing.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 except for the set of setscrew marks found near the end of the connector pin indicating the lead had not been fully inserted into the cavity of the generator.The additional 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.
|