Revision surgeries in cochlear implant patients: a review of 45 cases

The aim of this study was to analyze the causes for revision procedures, surgical findings and audiological outcome in reoperated cochlear implant patients. The medical records of 45 patients were reviewed retrospectively for age at the time of implantation, the implant was used for initial and revision surgeries, the duration of implant use before revision, surgical findings, and postoperative audiological results. Generally, children were reoperated more often than adults (12.5 vs. 6.9%) and, with one exception of improper electrode insertion, there were no major post-revision complications. Device failure (DF) was the main cause for revision surgery (23/45) followed by wound/flap problems, magnet/receiver-stimulator displacement, foreign body/allergic reaction, subperiosteal abscess, misplaced electrode, intractable vertigo, cholesteatoma and extrusion of the positioner. No significant difference was found in the rate of DF between children and adults for each implant separately (P = 0.289 for Nucleus 22, P = 0.355 for Nucleus 24, P = 0.683 for Clarion and P = 1.0 for Med-El). The failure rates of different implants did not differed significantly among adults. DF in the Clarion group was significantly higher compared to the Nucleus and Med-El combined for pediatric patients (P = 0.0218) and all CI recipients (adults + children; P = 0.0055). The post-revision audiological benefit was unchanged or improved compared to the initial implantation values in all reimplanted patients and was not influenced by minor surgical procedures (wound revision, drainage of any collection, magnet replacement, or relocation of receiver-stimulator). Since DF was found to be the most common cause for reoperation, improving device technology could prevent the vast majority of revision procedures.