Cochlear Implantation Outcomes in Patients with Mitochondrial Hearing Loss: A Systematic Review and Narrative Synthesis.

This study's aim was to establish outcomes following cochlear implantation (CI) in patients with mitochondrial disorders associated with deafness. Systematic review and narrative synthesis. Databases searched: Medline, EMBASE, Web of Science, COCHRANE, and ClinicalTrials.gov. No limits on language or year of publication. Review was conducted in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses statement. Searches identified 437 abstracts and 37 full text articles, of which 11 studies met the inclusion criteria reporting outcomes in a total of 17 patients. All implants achieved good hearing outcomes, and follow-up ranged between 1 week and 12 months. The methodological quality of the included studies was sufficient, scoring grades 3 to 4 using the Oxford Centre for Evidence Based Medicine grading system. All studies were retrospective and consisted of case reviews and case reports. All cases of CI showed positive outcomes in speech perception and detection. There is some qualitative evidence to suggest improvement in quality of life and satisfaction postoperatively. There was very limited information available on secondary outcomes such as surgical complications, quality of life, and method of cochlear implant insertion. The small sample size of our patient cohort and quality of studies suggests a need for large-scale studies with more robust methodology to assess the effectiveness of CI. There is a need for studies that assess other factors to be considered when counseling patients about cochlear implants, such as adverse events, surgical complications, and long-term benefits.