A systematic review and meta-analysis of the outcomes of anal fistula clips in the treatment of anal fistulas.

INTRODUCTION

One recent novel method for the treatment of anal fistulas is the over-the-scope clip. This meta-analysis aimed to examine the success of anal fistula clips.

METHODS

This Preferred Reporting Items for Systematic Reviews and Meta-Analyses-compliant systematic review searched PubMed, Scopus, and Cochrane Library from January 2000 through March 2025 for observational and randomized controlled trials that used over-the-scope clips in treating cryptoglandular and inflammatory bowel disease-related anal fistulas. Main outcomes were pooled healing and complication rates, and length of stay.

RESULTS

12 studies (2 randomized controlled trials) incorporating a total of 438 patients were included; 293 patients underwent anal fistula clip placement. The median age of the patients was 45.5 years. The pooled healing rate was 67.7% (95% confidence interval: 54.7%-80.7%) with a median follow-up of 11.3 months. Pooled healing was 78.7% (95% confidence interval: 62.3%-95.1%) in cryptoglandular fistulas and 59.5% (95% confidence interval: 41.8%-77.2%) in studies that included both cryptoglandular and inflammatory bowel disease fistulas. The medical hospital stay across 3 studies was 4.9 days. Pooled complication rate was 30.9% (95% confidence interval: 14.6%-47.2%). The most common complications were spontaneous migration or unscheduled removal of a clip (17.3%, 95% confidence interval: 8.3%-26.4%) and clinically significant pain (3.8%, 95% confidence interval: 0.9%-6.7%). Seven studies assessed continence after over-the-scope clip placement, and no cases of fecal incontinence were reported.

CONCLUSIONS

The over-the-scope clip is a promising and novel minimally invasive treatment for anal fistulas. The pooled healing rate was 67.7% overall and >75% for cryptoglandular fistulas. Despite its encouraging success, the over-the-scope clip's complication rate of 30.9% highlights the need for further refinement of this technique and patient selection.