Symptom Timeline Preceding Cochlear Implant Failure

Abstract

Review cochlear explants and determine the incidence of device and medical failures and develop a pattern of symptoms indicating probable implant failure. Case series with chart review. Tertiary referral center. Subjects were selected if they underwent cochlear explantation. Data were reviewed to determine initial symptom and symptom timeline preceding implant failure. A total of 847 implants were performed from 1988 to 2008, with 128 devices explanted. Of total implants, 72% were Advanced Bionic devices, and 28% were Cochlear Nucleus devices. Overall failure rate was 128 of 847 (15%), with 51 (6%) medical failures and 77 (9%) device failures. Patients with Advanced Bionic devices underwent 102 explants (16.7% failure rate), with 35% medical failures and 65% device failures. Patients with Nucleus devices underwent 26 explants (11% failure rate), with 58% medical failures and 42% device failures. Medical failures included infected devices and wound dehiscence, with the pattern averaging 4.5 months to explantation. Hard device failures included sudden malfunction and slow decline in function, with pattern of failure over 4.2 months. Soft failures included tinnitus and discomfort, with failure over 8 months. There were common patterns when evaluating both medical and device failures. By recognizing patterns of symptoms that may indicate probable implant failure, otolaryngologists can better counsel patients on what to expect with their implants when they present with certain symptoms.