Electrode migration after cochlear implantation.

OBJECTIVE: To review the occurrence of electrode migration after cochlear implantation. STUDY DESIGN: Review of public database and retrospective case series. SETTING: Tertiary academic referral center, ambulatory. PATIENTS: Retrospective review of electrode migration reported in association with the US Food and Drug Administration Manufacturer and User Facility Device Experience database and a single-institution case series between 1996 and 2006. INTERVENTION: Cochlear implantation. MAIN OUTCOME MEASURE: Occurrence of electrode migration. RESULTS: During the period 1996 to 2006, 151 reports of electrode migration were filed in the Manufacturer and User Facility Device Experience database. The most common association with migration was cochlear ossification, although 127 of 151 cases had no known association. During an equivalent period, 637 cochlear implant (CI) procedures were performed at the University of Miami. Of 580 primary CI operations, 2 cases of electrode migration were identified, both associated with reossification of a cochlea that was fully ossified at the first procedure. CONCLUSION: Electrode migration is an underrecognized complication of CI surgery and may be associated with cochlear ossification. Electrode stabilization techniques may reduce the incidence of CI electrode migration in nonossified or incompletely ossified cases.