Introduction: Ileal pouch-anal anastomosis (IPAA) for indeterminate colitis (IndC) may lead to an increased risk of perineal complications and pouch loss. This study evaluated pathological subgroups of IndC to identify a predictor of increased complication rates after IPAA for IndC.
Patients and methods: Of 171 IPAAs with a postoperative diagnosis of IndC, IndC was confirmed in 115 of the 140 specimens available for re-examination. These were divided into IndC favouring ulcerative colitis (Group I; n = 99), 'true' IndC (Group II; n = 8), and IndC favouring Crohn's (Group III; n = 8). 61 presented with fulminant colitis. Patients in Group I were subdivided into having (A) deep ulcers (B) transmural lymphoid aggregates (C) skip lesions (D) terminal ileal inflammation and/or (E) a caecal patch. Outcome was determined by chart analysis, and compared to 231 randomly selected patients with IPAA for ulcerative colitis (UC) matched for age, gender, and follow-up.
Results: Only patients with evidence of deep ulceration (Group IA) had a significant increase in the incidence of Crohn's disease (4.3%vs. 0.43%, P = 0.04), complex perianal fistulae (4.3%vs. 0.43%, P = 0.04), and pelvic abscess (12.9%vs. 2.2%, P < 0.001). No pathological subgroup of IndC patients had a significantly different rate of pouch failure or pouch loss.
Conclusions: Pathological stratification may predict those more likely to develop Crohn's disease or other complications, but not pouch failure. On this basis, we feel that patients with IndC should not be precluded from having IPAA surgery.