Advancement Flap Technique for Anal Fistula in Patients With Crohn's Disease: A Systematic Review of the Literature.

INTRODUCTION: Treatment for anal fistulas in patients with Crohn's disease is still challenging, even for the expert surgeon. The advancement flap technique is characterized by the preservation of the anal sphincter complex.

METHODS: A systematic review of the literature, selecting series of patients affected by Crohn's disease and anal fistulas and treated using advancement flap technique was performed. Patients followed during at least 6 months have been included.

RESULTS: From 128 initial studies, 11 studies were selected, including overall 135 patients. Those studies show low- level evidence. Results in a series with follow-up from 8,4 to 82 months, stated a clinical success of 66% and recurrence rate around 30%. However there was an evident heterogeneity of results.

CONCLUSION: The review concludes that the advancement flap technique to treat anal fistulas in patients with Crohn's disease is an adequate alternative. New studies are necessary to provide higher-level evidence.