Cochlear implantation in far advanced otosclerosis: a systematic review and meta-analysis

Objective: To evaluate speech outcomes and facial nerve stimulation (FNS) rates in patients with far advanced otosclerosis (FAO) after cochlear implantation. Methods: A systematic review was performed using standardized methodology of Medline, EMBASE, PubMed, Cochrane, and Web of Science databases. Studies were included if adults with FAO underwent cochlear implantation. Exclusion criteria included concurrent otologic history (e.g., Meniere's disease, superior canal dehiscence), non-English-speaking implant users, case reports, abstracts, and letters/commentaries. Bias was assessed using the Newcastle-Ottawa Scale for cohort studies and the National Institute of Health Scale for case series. The primary outcome measure was speech discrimination and the secondary outcomes were rates of partial insertion and FNS. Results: Twenty-seven studies evaluated cochlear implantation in FAO. Due to the heterogeneity of testing methods, statistical pooling of speech discrimination was not feasible, but qualitative synthesis indicated a positive effect of implantation. Pooled rates of FNS were 18% (95% confidence interval, CI 12%–27%) and the rate of partial insertion was 10% (95% CI 7%–15%). Conclusion: Cochlear implantation in FAO demonstrates significant gains in speech discrimination scores with higher rates of FNS and partial insertion.