Long-term ileoanal pouch survival after pouch urinary tract fistulae.

Background: Ileoanal pouch is a demanding procedure with many potential technical complications including bladder or ureteral injury, while inflammation or stricture of the anastomosis or anal transition zone may lead to the formation of strictures and fistulae, including to the adjacent urethra. Pouch urinary tract fistulae are rare. We aimed to describe the presentation, diagnostic workup, and management of patients with pouch urinary at our center.

Methods: Our prospectively maintained pouch registry was queried using diagnostic codes and natural language processing free-text searches to identify ileoanal pouch patients diagnosed with any pouch-urinary tract fistula from 1997 to 2022. Descriptive statistics and pouch survival using Kaplan-Meier curves are presented. Numbers represent frequency (proportion) or median (range).

Results: Over 25 years, urinary fistulae were observed 27 pouch patients; of these, 16 of the index pouches were performed at our institution [rate 0.3% (16/5236)]. Overall median age was 42 (27-62) years, and 92.3% of the patients were male. Fistula locations included pouch-urethra in 13 patients (48.1%), pouch-bladder in 12 patients (44.4%), and anal-urethra in 2 (7.4%). The median time from pouch to fistula was 7.0 (0.3-38) years. Pouch excision and end ileostomy were performed in 12 patients (bladder fistula, n = 3; urethral fistula, n = 9), while redo ileal pouch-anal anastomosis (IPAA) was performed in 5 patients (bladder fistula, n = 3; urethral fistula, n = 2). The 5-year overall pouch survival after fistula to the bladder was 58.3% vs. 33.3% with urethral fistulae (p = 0.25).

Conclusion: Pouch-urinary tract fistulae are a rare, morbid, and difficult to treat complication of ileoanal pouch that requires a multidisciplinary, often staged, surgical approach. In the long term, pouches with bladder fistulae were more likely to be salvaged than pouches with urethral fistulae.