Analysis of the returned lead portion was completed.During the visual analysis the positive connector ring quadfilar coil appeared to be broken approximately 20mm from the electrode bifurcation and the negative connector pin quadfilar coil appeared to be broken at approximately 22mm.Scanning electron microscopy was performed on the positive connector ring quadfilar coil break (found at 20mm) 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 negative connector pin quadfilar coil break (found at 22mm) and identified the area on two of the quadfilar coil strands as having evidence of a stress induced fracture (fatigue appearance) with mechanical damage, fine pitting and evidence of a stress induced fracture (torsional appearance) which most likely completed the fracture on one of the broken coil strands.The areas on the remaining broken quadfilar coil strands were identified as being mechanically damaged which prevented identification of the coil fracture type with fine pitting and residual material.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.With the exception of the observed discontinuities, 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 portion were performed, during the visual analysis, and no other discontinuities were identified.Note that the electrodes were not returned for analysis; therefore a complete evaluation could not be performed on the entire lead product.
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