Underwater endoscopic ear surgery vs. microscopic open approach for repair of semicircular canal fistulae secondary to middle ear cholesteatoma: a systematic review and meta-analysis

Background: This work sought to compare ‘under water endoscopic ear surgery’ (UWEES) to traditional open microscopic approaches for repair of labyrinthine fistula in a systematic review. The primary outcome was sensorineural hearing preservation. Secondary outcomes included disease clearance, vestibular function, facial nerve function and other complications. Methods: A systematic review was performed by electronic database search including Medline (on Ovid platform), Embase (on Ovid platform), Cochrane Library (on Ovid platform) and Web of Science (on Web of Science platform) and a manual search of gray literatures including conference abstracts, clinical review trials and reference lists of relevant studies. Case series, clinical trials, literature reviews, randomised control trials (RCTs), retrospective studies and systematic reviews were included. Animal studies were not considered. Retrieved studies were screened by two independent reviewers, and data extracted from full texts. Risk of bias was assessed using the National Institute of Health quality assessment tool for case series. A meta-analysis of the treatment outcomes was performed using random effects model specifications. Tests of heterogeneity were conducted using Q statistic. P values were two-tailed at a 0.05 level of significance. Results: A total of 359 articles in the UWEES group were identified in the initial search, and 735 articles in the microscopic group. After screening, 4 articles underwent data extraction in the UWEES group and 39 articles in the microscopic group. A meta-analysis was performed. There was no statistically significant difference in hearing outcome post-operatively in both groups [standardized mean difference =−0.05, 95% confidence interval (CI): −0.44 to 0.34, P=0.81 for UWEES method and standardized mean difference =−0.56, 95% CI: −1.23 to 0.11, P=0.10 for microscopic]. There was a statistically significant reduction in post-operative vertigo using the microscopic approach (risk difference =−0.49, 95% CI: −0.58 to −0.40, P<0.001). Location of fistula and primary surgery had a significant relationship with the risk difference in incidence of vertigo (per patient increase in risk difference was: β=0.006, 95% CI: 0.002–0.01 for lateral semi-circular canal fistula, β=0.006, 95% CI: 0.001–0.011 for primary surgery). Conclusions: UWEES is potentially a safe and effective alternative to traditional microscopic approaches for labyrinthine fistulae repair. There was a low-moderate risk of bias in both groups with the majority of studies being of good quality. Limitations including a lack of raw data overall and inadequate follow up time in some patients due to the novelty of the technique. Further research should look at prospectively comparing both approaches in a single study.