Cochlear implant failure and revision surgery in pediatric population

This study aimed to report pediatric cochlear reimplantation data focusing on failure of the device and to assess surgical challenges and functional outcomes.

Retrospective case review from 1990 to 2012. Tertiary referral academic center. A retrospective review of medical and surgical records, audiologic results, and report of the manufacturer's analysis was performed. The causes of revision cochlear implantation were divided into hard failure and soft failure. Results compared speech perception in open set or closed set words before and after revision surgery with cochlear implant only.

During the study period, 877 cochlear implantations were performed. Our reimplantation rate for failure of the device is 5.7% (50 of 877). The main reasons for hard failure were loss of hermeticity and cracked casing following head trauma. Surgical difficulties might be due to neo-osteogenesis related to the use of bone dust. Initial atraumatic insertion is important to ensure that revision surgeries are less problematic. In postmeningitis deafness, initial choice of electrode array is of utmost importance. We would suggest a plain shape and a larger diameter array, to ensure sufficient subsequent insertion. Post-reimplantation audiologic results were the same or better than preoperative levels in 86% of cases.

Failure might be difficult to diagnose in children with limited language skills. The surgical team and patients should be aware of the surgical difficulties that can be encountered, especially in cases of meningitis or initial traumatic insertion. Auditory performances after reimplantation are the same or better in most cases.