Cochlear Implant Electrode Array Exposure: A Delayed Complication

Exposure of the cochlear implant electrode array as a late complication has been reported rarely in the literature. A retrospective analysis revealed 4 patients presenting with exposure of their cochlear implant electrode arrays from 2 to 17 years after implantation. Data collected from these 4 patients were surgical implantation approach, type of implant, age at implant, interval between implant and complication, surgical correction of the problem, pathology at the time of correction, and length of follow-up after intervention. All 4 patients presented with otitis or mastoiditis. Each had undergone a transmastoid approach with facial recess and cochleostomy and full implant insertion. In 3 cases, the tympanic membrane had retracted to expose the electrode array. In 1 patient, the electrode array had eroded through the external canal, lateral to the facial recess. The exposed arrays were addressed surgically, including explantation/reimplantation for 1 patient. Cochlear implant electrode arrays can become exposed by relative migration of the array and the tympanic membrane. Implant surgeons and audiologists need to be aware of the possibility of this complication. Closure of the ear canal appears to be the most effective surgical intervention.