Cochlear Implant Outcomes Following Vestibular Schwannoma Resection: Systematic Review

Objective: Hearing loss remains a significant morbidity for patients with vestibular schwannomas (VS). A growing number of reports suggest audibility with cochlear implantation following VS resection; however, there is little consensus on preferred timing and cochlear implant (CI) performance. Data Sources: A systematic literature search of the Ovid Medline, Embase, Scopus, and clinicaltrails.gov databases was performed on 9/7/2018. PRISMA reporting guidelines were followed. Study Selection: Included studies reported CI outcomes in an ear that underwent a VS resection. Untreated VSs, radiated VSs, and CIs in the contralateral ear were excluded. Data Extraction: Primary outcomes were daily CI use and attainment of open-set speech. Baseline tumor and patient characteristics were recorded. Subjects were divided into two groups: simultaneous CI placement with VS resection (Group 1) versus delayed CI placement after VS resection (Group 2). Data Synthesis: Twenty-nine articles with 93 patients met inclusion criteria. Most studies were poor quality due to their small, retrospective design. Group 1 had 46 patients, of whom 80.4% used their CI on a daily basis and 50.0% achieved open-set speech. Group 2 had 47 patients, of whom 87.2% used their CI on a daily basis and 59.6% achieved open-set speech. Group 2 had more NF2 patients and larger tumors. CI timing did not significantly impact outcomes. Conclusions: Audibility with CI after VS resection is feasible. Timing of CI placement (simultaneous versus delayed) did not significantly affect performance. Overall, 83.9% used their CI on a daily basis and 54.8% achieved open-set speech.