Revision cochlear implantation surgery in adults: Indications and results

OBJECTIVE: To assess the efficacy, risks, and indications of revision cochlear implantation (RCI) and to identify the clinical, audiologic, and device-related characteristics that predict outcome. STUDY DESIGN: Retrospective case series. SETTING: Academic tertiary referral center. PATIENTS: Adults (ĝ‰¥18 yr) who underwent RCI at Johns Hopkins University. INTERVENTION: Revision cochlear implant surgery. MAIN OUTCOME MEASURES: Speech perception by open-set testing and patient report and patient report of symptom resolution. RESULTS: During the 16-year period of this study, 4.8% of all adults implanted at our center have required 1 or more RCI surgeries. A total of 48 RCIs have been performed. The indications for RCI included infection (12%), electrode extrusion (15%), hard failure (23%), suspected device failure (42%), and isolated facial nerve stimulation (8%). Overall, successful resolution of the implant-related or medical condition was achieved with RCI in 83% of cases. Speech perception was lower in only 1 (2.1%) of 48 cases. Satisfactory preoperative speech recognition was preserved or surpassed in 5 of 6 infection cases and 8 cases with progressive symptoms of tinnitus and facial nerve stimulation. All cases of hard failure regained or surpassed previous peak performance. Improved speech recognition was experienced by 75% of cases with suspected device failure. Of cases in which RCI failed to restore previous functional benefit, there was a significant association with advanced age (>70 yr). Whereas an abnormal integrity test was predictive of favorable outcome after RCI, a negative test was not predictive of outcome. A similar pattern of results was observed with respect to ex vivo device analysis. CONCLUSION: Revision cochlear implantation can be safely performed to restore lost benefit in appropriately selected cases. When properly performed after medical and audiologic options have been exhausted, RCI rarely compromises previous function and, in most cases, can resolve functional complaints and distracting symptoms. When positive, integrity testing is a useful screen for the presence of a device defect. In cases in which device integrity is uncertain, clinical judgment guided by longitudinal assessment can help determine whether RCI is likely to be beneficial.