Predictors of reoperation for perianal fistula in Crohn's disease

Objective Treating perianal fistula in cases of Crohn's disease (CD) remains challenging and the postoperative recurrence rate of perianal fistula is 22%-28%. This study aimed to identify the predictive risk factors for reoperation in Korean CD patients with perianal fistula. Methods Medical records of the patients with clinically and pathologically confirmed CD who underwent surgical treatment for perianal fistulas at four referral centers in Korea between March 2010 and February 2020 were retrospectively reviewed. The rate of reoperation due to perianal fistula recurrence, which was defined as any subsequent surgery for perianal fistula or abscess, and the potential risk factors for reoperation were analyzed. Results Fifty-one patients at a mean age of 22 years were included in the study. During a median follow-up period of 26 months (range 2-89 mo), 21 (41.2%) patients underwent reoperation because of recurrent perianal fistula or abscess. The median interval from the first surgery to reoperation was 13 months. A multivariate Cox regression analysis revealed that drug escalation (from 5-aminosalicylic acid [5-ASA] to thiopurine or from 5-ASA or thiopurine to anti-tumor necrosis factor agents) after the first surgery was associated with a reduced likelihood of reoperation (hazard ratio 0.316, 95% confidence interval 0.117-0.858, P = 0.024). Conclusions The postoperative recurrence rate was relatively high (41.2%) after the first surgery for perianal fistula in Korean patients with CD. Drug escalation therapy after the first surgery may help reduce the need for reoperation for perianal fistula.