Hearing preservation and improved speech perception with a flexible 28-mm electrode.

OBJECTIVE: The present study aimed to determine the extent of hearing preservation retrospectively after atraumatic cochlear implant (CI) surgery using a specialized surgical technique and specially designed flexible electrode to minimize cochlear trauma. STUDY DESIGN: Retrospective study. SETTING: Academic tertiary care center. PATIENTS: A consecutive series of 34 patients who had some preoperative residual hearing were included in this study. INTERVENTION: Patients underwent CI surgery with a flexible 28-mm electrode using a round window insertion technique. MAIN OUTCOME MEASURES: All patients had at least 6 months of postoperative follow-up including audiometric testing and speech perception determined using the Freiburg monosyllable word test and the Oldenburger Sentence Test in noise. Audiometric testing served as a proxy for the evaluation of cochlear trauma and hearing preservation. RESULTS: Hearing was preserved to within 20 dB of preoperative low-frequency pure-tone audiometry (PTA) in 40.7% of patients. Hearing was preserved to within 20 dB of preoperative high-frequency PTA in 35.7% of patients. Overall, a deterioration in hearing thresholds was observed between preoperative assessment and first fitting. Speech perception improved significantly over time after surgery. CONCLUSION: Using appropriate surgical techniques, and electrodes specially designed to minimize cochlear trauma, hearing preservation can be achieved.