Optimum management for complex anal fistula: A network meta-analysis of randomized controlled trials

Complex anal fistula has a high recurrence rate and disturbing surgical complications, which are frustrating for patients and challenging for surgeons. Although single or combined management methods have produced positive outcomes, no trials have simultaneously compared these therapies. Therefore, this study aimed to determine the management method for complex anal fistula with the lowest failure and complication rates.

This network meta-analysis (NMA) was registered in the international prospective register of systematic reviews (PROSPERO; CRD42023393349). Randomized controlled trials that analyzed complex anal fistula management were obtained from Medline, Scopus, and Cochrane using representative keywords. The primary outcome was the failure of anal fistulas to heal (including recurrences) after 6 to 12 months. The secondary outcome was fecal incontinence. All statistical analysis was conducted within the Bayesian framework using BUGSnet 1.1.0 in R Studio. A forest plot and league table were used to present the results.

A total of 19 studies containing 15 interventions, 1844 subjects, and 104 pairwise comparisons were analyzed quantitatively. The lowest failure rates occurred with ligation of the intersphincteric fistula tract (LIFT) + Plug (RR 0.2; 95 % CI 0.01-2.65), LIFT + platelet-rich plasma (PRP) (RR 0.22; 95 % CI 0.01-2.89), and FSR (RR 0.26; 95 % CI 0.02-2.12) relative to drainage seton. LIFT combined with other management methods showed lower fecal incontinence rates than the other treatments.

The combination of LIFT with plug or PRP resulted in lower failure and complication rates in the management of complex anal fistula compared to the other methods tested.