Risk factors for complications in cochlear implant surgery

The objective of this study was to achieve uniform reporting of complications and failures in cochlear implantation, to analyze complications and failures and to identify risk factors for complications in a series of over 1300 cochlear implantations. In a retrospective chart review and observational study, data from all cochlear implantations from 1987 to 2015 were entered in a custom-made database. Complications were classified using the contracted form of the Clavien-Dindo system and risk factors were identified by statistical analysis. A complication rate of 18.4% and a device failure rate of 2.9% were found. There was a higher rate of hematoma in patients with a clotting disorder and when a subtotal petrosectomy was performed, a higher rate of wound infections in patients who were not vaccinated against Streptococcus pneumoniae and a higher rate of meningitis in patients with an inner ear malformation. The use of a strict definition of a medical complication and device failure-in combination with the Clavien-Dindo classification system-enables uniform and objective registration of adverse events and prevents any tendency to downgrade complications. Complication and failure rates in this series are comparable to those reported in the literature. These results stress the need for pneumococcal vaccination, which may prevent general wound infections, but is especially important for patients with inner ear malformation, who have an increased risk of (postoperative) meningitis.