Hearing improvement after cochlear implantation in common cavity malformed cochleae: long-term follow-up results

Conclusion: We suggest that cochlear implantation (CI) should be a good therapeutic modality for hearing restoration in patients with common cavity malformed ears. Objective: To analyze hearing improvement from CI performed in common cavity malformed cochleae. Methods: A total of 11 patients (5 male and 6 female, mean age 4.5 +/- 2.8 years) and 12 ears were enrolled in this study. During the insertion of electrodes, we used C-arm fluoroscopy to avoid intrameatal placement. We evaluated hearing improvement every 6 months and the mean follow-up period was 80.5 +/- 24.1 months (53-125 months). Results: During the operation, there were only four cases with fully inserted electrodes. Cerebrospinal fluid gushed out in two cases during the cochleostomy and postoperative meningitis occurred in two patients. One patient had to undergo reimplantation 4 years later due to device failure and recurrent meningitis. During the 48 months follow-up hearing evaluation, the ability of hearing increased along with the age. The final average MAIS, CAP, SIR, and open set one-and two-syllable word scores were 90.3 +/- 18.1%, 4.9 +/- 1.6, 3.1 +/- 0.9, 24.1 +/- 25.9%, and 48.6 +/- 38.7%, respectively.