Cochlear Implant Electrode Failure Secondary to Silicone Touch-Up During Device Manufacturing

Abstract

Retrospective case report. Tertiary referral cochlear implant center. A 21-year-old woman was implanted with Advanced Bionics HiFocus Clarion device without complication. Five years later, the patient presented with dizziness, fluctuating implant performance, and facial pain. Surgical exploration revealed a torn electrode silicon casing in conjunction with scar contraction bending the electrode against bony facial nerve canal at the facial recess. Suspension of the electrode such that the damaged portion was not in contact with mastoid cavity led to temporary resolution of symptoms. Explantation and reimplantation procedures were carried out 2 months later. Postexplantation device analysis by the manufacturer demonstrated silicone touch-up at the site of failure. Six years since reimplantation, the patient has remained symptom-free. It is very likely that the touch-up silicon weakened the electrode and, in conjunction with chronic scar contraction, led to the tear on the silicon casing. Isolated cochlear implant electrode failure is a rare but possible long-term complication in older generation devices. The author reports 1 case of implant device failure partly because of silicon touch-up that was applied at the location of electrode failure during its manufacturing process.