Impact of cochlear abnormalities on hearing outcomes for children with cochlear implants

Objective: Evaluate the impact of cochlear anomalies on hearing outcomes for pediatric patients with cochlear implants. Study design: Retrospective chart review. Setting: Tertiary care center. Subjects and methods: Charts were retrospectively reviewed for cases where pediatric cochlear implant surgery was performed between 2002 and 2018 at a single, tertiary care institution. Patients were divided into groups based on the presence or absence of radiological cochlear abnormalities, which were further classified as low or high risk anomalies. Hearing outcomes were evaluated by measuring pure tone averages and word recognition scores preoperatively, 3 and 12 months postoperatively, in addition to the most recent test results. Results: There were 154 ears implanted in our cohort of 100 patients. 107 ears had normal cochlear anatomy, 31 had low risk, and 16 had high risk abnormalities. The most common modality of preoperative imaging was CT scan. Postoperative mean pure tone average (PTA) was significantly higher in patients with inner car anomalies compared to those with normal anatomy. No significant difference in PTA was noted between low versus high risk patients. < 50% of patients had word recognition scores available within the first year following surgery. Conclusion: Abnormalities of the inner ear significantly influenced hearing outcomes over time following cochlear implant surgery when compared to pediatric patients with normal anatomy. Obtaining hearing testing can be difficult in very young children and therefore future studies are warranted to further investigate the impact that cochlear abnormalities may have on hearing outcomes following cochlear implant surgery.