Surgical management of anal fistulae: a systematic review

Objective The anal fistula has been a common surgical ailment reported since the time of Hippocrates but little systematic evidence exists on its management. We aimed to systematically review the available studies relating to the surgical management of anal fistulas. Method Studies were identified from PubMED, EMBASE, Cochrane Controlled Trials Register, ClinicalTrials.Gov and Current Controlled Trials. All uncontrolled, nonrandomized, retrospective studies, duplications or those unrelated to the surgical management of anal fistulas were excluded. Results The search strategy revealed 443 trials. After exclusions 21 randomized controlled trials remained evaluating: fistulotomy vs fistulectomy (n = 2), seton treatment (n = 3), marsupialization (n = 2), glue therapy (n = 3), anal flaps (n = 3), radiosurgical approaches (n = 2), fistulotomy/fistulectomy at time of abscess incision (n = 5) and intra-operative anal retractors (n = 1). Two meta-analyses evaluating incision and drainage alone vs incision + fistulotomy were obtained. Conclusion Marsupialization after fistulotomy reduces bleeding and allows for faster healing. Results from small trials suggest flap repair may be no worse than fistulotomy in terms of healing rates but this requires confirmation. Flap repair combined with fibrin glue treatment of fistulae may increase failure rates. Radiofrequency fistulotomy produces less pain on the first postoperative day and may allow for speedier healing. Major gaps remain in our understanding of anal fistula surgery.