Anorectal stricture in 102 patients with Crohn's disease: natural history in the era of biologics

Background The natural history of nonfistulising perianal Crohn's disease (PCD) remains unknown. Aim To assess the long-term outcome of anorectal strictures. Methods All outcomes of PCD patients with anorectal stricture followed in a single unit from 2005 to 2013 were reviewed, as well as subsequent therapeutic management. Cumulative incidence of stricture healing (disappearance of the anal stricture) was estimated using a Kaplan-Meier method and factor associated with an unfavourable course (persistent stricture S2, persistent stoma or proctectomy) with nonparametric test. Results A total of 102 patients (M/F: 37/65) were included. The duration of CD at diagnosis was 8.9 years. After a median follow-up period of 2.8 years, 52 of the 88 followed patients (59%) achieved anorectal stricture healing. Two patients (2%) developed anal adenocarcinoma. Female gender [HR 2.05 (1.1-4.03), P = 0.0221], disease duration of CD of less than 10 years [HR 1.94 (1.01-3.63), P = 0.0271], and anal fistula at stricture diagnosis [HR 2.36 (1.21-5.05), P = 0.0106) were significantly associated with anorectal stricture healing in a multivariate analysis model. Twenty-eight patients (32%) had an unfavourable course at the end of follow-up. Gender and introduction or optimisation of TNF alpha antagonist treatment decreased the risk of unfavourable course in multivariate analysis. Conversely, the Luminal B2 phenotype at CD diagnosis was the only factor associated with unfavourable course. Conclusions Anorectal stricture does not imply a nonreversible and complicated condition related to severe perianal Crohn's disease. However, both the diagnosis of cancer and sepsis drainage remain challenging in this situation.