Cochlear Implant Failures and Revision

Objective: To review cases involving implant failure and revision surgery in a large cochlear implant program. Study Design: Retrospective case series. Setting: Cochlear implant program in an academic medical center. Patients: Adults and children who underwent revision cochlear implantation (n = 58). Intervention: Diagnosis and explantation of failed cochlear implants, with subsequent reimplantation. Assessment of implant function and speech perception. Main Outcome Measures: Device type, time from implantation to revision, cause of failure, performance with original implant versus revision, number of electrodes placed, and surgical challenges related to reimplantation. Results: Forty-five patients initially implanted at this program and 13 patients implanted elsewhere underwent revision surgery. The institutional device failure rate was 3.7% and the overall revision rate was 5.1%. Reasons for implant revision included documented internal device failure (46%), scalp flap complications (17%), optimization of electrode placement (13%), unexplained deterioration of performance (12%), technology upgrade (10%), and intratemporal pathology (3%). Revision surgery typically involved only minor anatomic challenges, but five patients required circumodiolar drillout procedures to improve electrode position. Electrode insertion was equal or deeper in 53 of 58 cases. Speech perception ability decreased in only three patients. Conclusions: Management of implant failures and performance of revision surgery are becoming increasingly important in cochlear implant programs. Outcomes are generally excellent. Revision implantation is a safe and appropriate procedure that should be pursued in a timely fashion when patients experience cochlear implant failure.