Objectives: Abdominal colectomy has been used in patients with inflammatory bowel disease unclassified (IBDU), requiring surgery to allow histopathological evaluation of the colectomy specimen to rule out Crohn's disease (CD). We evaluated whether any histopathological feature was associated with an adverse postoperative outcome.
Methods: Patients with ulcerative colitis (UC) or IBDU undergoing ileal pouch-anal anastomosis (IPAA) were prospectively examined. A checklist of 17 histopathological features atypical for UC was developed. Outcomes of acute pouchitis (AP), chronic pouchitis (CP), and de novo CD were assessed.
Results: The 153 study patients included 119 (78%) UC and 34 (22%) IBDU patients. The following atypical features were identified (n; %): broad-based ulcer (99; 65%), appendiceal involvement (78; 51%), V-shaped ulcer (48; 31%), crypt-associated granuloma (42; 27%), isolated giant cells (39; 25%), discontinuous active inflammation (36; 24%), slit-like fissure (32; 21%), discontinuous chronic inflammation (16; 10%), ileal villous architectural distortion (12; 8%), neural hypertrophy (10; 7%), backwash ileitis (10; 7%), transmural inflammation (8; 5%), discontinuous ileitis (8; 5%), muscle hypertrophy (5; 3%), ileal ulcer (4; 3%), and ileal pyloric metaplasia (1; 1%). A total of 29 patients (19%) developed AP, 17 (11%) developed CP, and 13 patients (8%) developed de novo CD. On univariate analysis, de novo CD developed in 3 of the 10 patients (30%) with neural hypertrophy compared with only 10 of the 143 patients (7%) without neural hypertrophy (P=0.01). Multivariate regression did not show a single atypical histopathological feature, which predicted a worse outcome after IPAA.
Conclusions: No single atypical histopathological feature of UC, or combination of features, was associated with any adverse pouch outcome after IPAA. There seems to be no value in performing a staged IPAA in IBDU patients.