Systematic review and meta-analysis of Transanal Opening of Intersphincteric Space (TROPIS) versus conventional treatments for anal fistula.

Transanal Opening of Intersphincteric Space (TROPIS) has emerged as a promising surgical approach for anal fistula management over recent years. This meta-analysis comprehensively evaluates the comparative efficacy and safety of TROPIS versus conventional treatments through systematic analysis of 24 clinical studies involving 2813 patients. Through systematic searches across 7 major biomedical databases (including PubMed, EMBASE, and Chinese repositories) from inception to March 2024, we identified comparative studies assessing TROPIS against six established interventions: incision-thread-drawing, seton placement, LIFT, EAFR, fistulotomy, and incision-suture techniques. Pooled analysis demonstrated TROPIS achieved superior clinical outcomes, with a 3.15-fold higher total efficacy rate (95 % CI 1.22-8.13,  = 0.02) and 64 % lower complication risk compared to conventional methods (OR 0.28, 95 % CI 0.18-0.42,  < 0.00001). Sensitivity analyses confirmed result stability across study designs, while publication bias assessment via funnel plots and Egger's test revealed no significant distortion. Importantly, TROPIS maintained its advantage across various complication subtypes including incontinence (OR 0.31), infection (OR 0.27), and recurrence (OR 0.19). These findings establish TROPIS as a clinically superior alternative that significantly improves therapeutic outcomes while reducing procedure-related risks, suggesting its potential to become the new reference standard in anal fistula management. The consistent results across diverse patient populations and comparator procedures underscore the robustness of this evidence synthesis.