Management of perianal fistulas in Crohn's disease: a 2021 update of the French National Society of Coloproctology consensus.

Background: Since our last publication of algorithms for the management of perianal fistulas in patients with Crohn's disease, researchers have proposed a treat to target strategy systematic combotherapy for anal lesions, and indications for stem cell injection. In the absence robust publications, the Société Nationale Française de Coloproctologie (French National Society of Coloproctology [SNFCP]) wished to establish a group consensus using the Delphi method.

Methods: From October 2020 to January 2021, a scientific committee and panel of gastroenterologists and surgeons established answers which were submitted to the members of the SNFCP during a national conference in November 2020. Three questions were clarified and reformulated, and then submitted during a third and final round of consultation of members of the SNFCP.

Results: The target was defined as being the response obtained in every domain (symptoms, physical and radiological evaluation) which could be considered satisfactory, without the need to intensify therapeutic management. By consensus, the time required for clinical evaluation of the efficacy of treatment was 6 months. A response on magnetic resonance imaging (MRI) should include the absence of a collection of 10 mm or more in size at 6 months, and a frank decrease or complete disappearance of hyperintensity in T1 and T2 sequences of the main tract at 12 months. Systematic association of an immunosuppressant with tumor necrosis factor inhibitors did not reach the consensus level for adalimumab (50%), but just did for infliximab (70%). The majority of the respondents considered failure of one, or even two lines of different biotherapies to be potential indications for injection of stem cells.

Conclusions: These findings reinforce the importance of composite targets including MRI evaluation, and underscore the need for precise timing of evaluation. Combotherapy is only recommended with infliximab. Injection of stem cells is a second- or third-line option.