Anti-TNF therapy for genital fistulas in female patients with Crohn's disease: a nationwide study from the Groupe d'Etude Thérapeutique des Affections Inflammatoires du tube Digestif (GETAID).

Background: Genital fistulas represent a devastating complication of Crohn's disease. Only studies with small sample sizes have evaluated the efficacy of anti-TNF therapy for this complication.

Aims: To assess the efficacy of anti-TNF therapy for genital fistulas complicating Crohn's disease and to identify predictive factors associated with clinical response at 1 year.

Methods: Consecutive patients treated with anti-TNF therapy for genital fistulas complicating Crohn's disease from 1999 to 2016 in 19 French centres from the Groupe d'Etude Thérapeutique des Affections Inflammatoires du tube Digestif were included in a retrospective cohort study. Outcome was clinical fistula closure at 1 year.

Results: Among the 204 women with genital fistulas who received anti-TNF therapy, 131 were analysed. The first anti-TNF given was infliximab (79%), adalimumab (20%), or certolizumab (1%). At start of anti-TNF therapy, 56% of patients had seton drainage and 53% had concomitant immunosuppressive treatment. A complementary surgery was performed during the first year in 10 patients (8%). At 1 year, 37% of patients had complete clinical fistula closure, 22% had a partial response, and 41% had no response. Among patients without complementary surgery, 34% (41/121) had complete clinical fistula closure. Only complementary surgery was associated with better response on multivariate analysis (adjusted relative risk: 2.02, 95% CI: 1.25-3.26, P = 0.0043).

Conclusions: In the anti-TNF era, approximately one-third of patients with genital fistula in Crohn's disease had complete fistula closure at 1 year. Collaboration between surgeons and gastroenterologists appears to be very important to improve the rate of fistula closure.