Pedictors of Perianal Fistula Relapse in Crohn's Disease

Despite an optimal medico-surgical management of perineal Crohn's disease (PCD), fistula relapse still occurs in 30% of patients. Our aim was to determine predictors of fistula relapse in patients in remission after treatment of a PCD lesion.

Consecutive patients treated for fistulizing PCD have been included in a retrospective study when they achieved fistula remission within 3 months after the surgery. Remission was defined as the absence of any draining fistula at clinical examination. Primary outcome was the occurrence of a fistula relapse, defined as a subsequent perianal draining fistula or an abscess confirmed clinically and/or by pelvic MRI.

One hundred and thirty-seven patients (57% female, median age: 35 years) corresponding to 157 abscess events, including 120 (76.4%) treated by anti-TNF after drainage, achieved fistula remission after surgery. During the follow-up period (median duration: 43 months [interquartile range 26 to 64]), 34 (22%) patients experienced a fistula relapse within a median time of 1.8 years. Survival without fistula was 96.7% at 1 year, 78.4% at 3 years, and 74.4% at 5 years. Fistula relapse rates were not different in patients receiving infliximab or adalimumab (P = 0.66). In patients treated by anti-TNF at inclusion, discontinuation of anti-TNF therapy (odds ratio 3.49, P = 0.04), colonic location (OR 6.25, P = 0.01), and stricturing phenotype (odds ratio 4.39, P = 0.01) were independently associated with fistula relapse in multivariate analysis.

In patients achieving fistula remission of PCD, relapse rates are low and are not different between infliximab and adalimumab. Discontinuation of anti-TNF therapy is associated with increased relapse rate.