Systematic Review and Meta-analysis of Surgical Complications following Cochlear Implantation in Canal Wall Down Mastoid Cavities.

OBJECTIVE We sought to assess the complication rates following cochlear implantation in canal wall down mastoid cavities in adults and children. DATA SOURCES A systematic review of English articles from PubMed, Web of Science, EMBASE, and the Cochrane Library. Additional studies were identified by reviewing the reference lists of the originally identified studies. REVIEW METHODS Studies were included that reported on surgical outcomes following cochlear implantation in canal wall down mastoid cavities. Two authors, using predefined data fields, independently reviewed all articles while tabulating study quality indicators. A meta-analysis of proportions was conducted on select cohorts to determine weighted complication rates. RESULTS Forty-two articles were included that accounted for 424 patients and described surgical outcomes following cochlear implantation in canal wall down mastoid cavities. In a comparison of the postoperative complication rates, overclosing the external auditory meatus had significantly fewer global complications than did maintaining a canal wall down mastoid cavity (P = .027). In a comparison of the complication rates (1) between staging the cochlear implantation and performing external auditory meatus overclosure simultaneously with cochlear implantation and (2) between pediatric and adult cochlear implantation recipients with external auditory meatus overclosure, there were no significant differences (P = .085 and P = .92, respectively). CONCLUSION Overclosing the external auditory meatus at the same time of cochlear implantation leads to significantly fewer complications when compared with maintaining a canal wall down mastoid cavity with soft tissue coverage of the electrode array.