Endorectal advancement flap compared to ligation of inter-sphincteric fistula tract in the treatment of complex anal fistulas: A meta-analysis of randomized clinical trials

Background: Rectal advancement flap and ligation of intersphincteric fistula tract are common procedures for treating complex anal fistula. The present meta-analysis aimed to compare the surgical outcomes of advancement flap and ligation of intersphincteric fistula tract. Methods: A Preferred Reporting Items for Systematic Reviews and Meta-Analyses–compliant systematic review of randomized clinical trials comparing the ligation of intersphincteric fistula tract and advancement flap was conducted. PubMed, Scopus, and Web of Science were searched through January 2023. The risk of bias was assessed using the Risk of Bias 2 tool and certainty of evidence with the Grading of Recommendations Assessment, Development and Evaluation approach. The primary outcomes were healing and recurrence of anal fistulas, and secondary outcomes were operative time, complications, fecal incontinence, and early pain. Results: Three randomized clinical trials (193 patients, 74.6% male) were included. The median follow-up was 19.2 months. Two trials had a low risk of bias, and 1 had some risk of bias. The odds of healing (odds ratio: 1.363, 95% confidence interval: 0.373–4.972, P =.639), recurrence (odds ratio: 0.525, 95% confidence interval: 0.263–1.047, P =.067), and complications (odds ratio: 0.356, 95% confidence interval: 0.085–1.487, P =.157) were similar between the 2 procedures. Ligation of intersphincteric fistula tract was associated with a significantly shorter operation time (weighted mean difference: –4.876, 95% confidence interval: –7.988 to –1.764, P =.002) and less postoperative pain (weighted mean difference: –1.030, 95% confidence interval: –1.418 to –0.641, 0.198, P <.001, I² = 3.85%) than advancement flap. Ligation of intersphincteric fistula tract was associated with marginally lower odds of fecal incontinence than advancement flap (odds ratio: 0.27, 95% confidence interval: 0.069-1.06, P =.06). Conclusion: Ligation of intersphincteric fistula tract and advancement flap had similar odds of healing, recurrence, and complications. The odds of fecal incontinence and extent of pain after ligation of intersphincteric fistula tract were lower than after advancement flap.