Pouch advancement flaps for the surgical management of complex pouch-related fistulas: Is there a difference between pouch perineal and pouch vaginal fistulae?

Background: Pouch-related fistulas occur in 5% to 12% of patients with ileal pouch-anal anastomosis. Although cryptoglandular and Crohn-related fistulas are commonly treated with endorectal advancement flaps, the use of pouch-advancement flaps has not been previously reported in isolation. Our aim was to evaluate the outcomes of pouch-advancement flaps in the management of pouch-related fistulas and compare the outcomes of pouch-vaginal and pouch-perineal fistulas.

Methods: We retrospectively reviewed all patients with ileal pouch-anal anastomosis who underwent pouch-advancement flap surgery at our center. Our primary endpoint was sustained fistula healing after pouch-advancement flap surgery without the need for additional surgery at any time during long-term follow-up.

Results: Thirty patients met our inclusion criteria: 14 (46.7%) presented with pouch-perineal fistula, 14 (46.7%) with pouch-vaginal fistula, and 2 (6.6%) with both. Multibranched complex fistulas were diagnosed in 6 patients (20%). In 9 patients (30%), the pouch-advancement flap was protected with diverting loop ileostomy. After a median follow-up period of 25.7 months (range 4.8-43.1 months), the pouch-advancement flap was initially successful in 19 patients (63%), with no difference between pouch-perineal and pouch-vaginal fistulas (P = 1.0). After the initial healing, 14 of 19 patients (73.7% or 46% overall) had sustained healing, while 5 of 19 (26.3%) had fistula recurrence. Fecal diversion and other fistula characteristics were not associated with pouch-advancement flap healing (P = 1.0).

Conclusions: Pouch-advancement flaps were initially successful in two thirds, with a recurrence rate after initial healing of 26.3%, regardless of whether they were pouch-perineal or pouch-vaginal. The role of fecal diversion before pouch advancement flap remains unclear, and larger, multicentric collaborative studies are needed to clarify its role.