Ileoanal Pouch-Related Fistulas: A Narrative Review

Ileoanal pouch-related fistula (IAPRF) is a possible complication after ileal pouch-anal anastomosis that significantly impacts pouch prognosis and the patient's quality of life. This study aimed to perform a comprehensive narrative review to better classify the epidemiology, risk factors, etiology, management, and outcomes of IAPRF, and to propose an algorithm for its systematic classification. Ten studies comprising 664 patients with IAPRF were identified, with a prevalence ranging from 4% to 45%. The reported fistula types were as follows: pouch-vaginal (n = 236, 35.5%), perineal (n = 139, 21%), enterocutaneous (n = 54, 8%), pouch-anal (n = 53, 8%), presacral (n = 18, 2%), and anastomotic (n = 15, 2%). Postsurgical pelvic sepsis occurred in 21%-37.2% of patients. Twenty additional studies regarding fistula classification divided them according to onset time and etiology, defining 5 categories: anastomotic-related, technical aspects of the surgery, Crohn's disease-like pouch inflammation, cryptoglandular, and malignancy. Pouch excision was reported in up to 70% of patients. Fistulas associated with anastomotic complications, technical surgical issues, and cryptoglandular fistulas warrant surgical management. On the other hand, fistulas associated with inflammation are preferentially managed with biologics or small molecules.