Histologic Predictors of Clinical Outcomes and Healthcare Utilization in Patients With Ileal Pouch-Anal Anastomosis

Lay Summary In this retrospective cohort study, histologic variables of acute and chronic inflammation were associated with future development of chronic pouchitis, need for biologic or small molecule treatment for chronic pouchitis, and hospitalization. Background The prognostic significance of histology in ileal pouch-anal anastomosis (IPAA) remains unclear. The aim of this study was to evaluate if histologic variables are predictive of IPAA clinical outcomes and healthcare utilization. Methods This was a retrospective cohort study of patients with IPAA undergoing surveillance pouchoscopy at a tertiary care institution. Pouch body biopsies were reviewed by gastrointestinal pathologists, who were blinded to clinical outcomes, for histologic features of acute or chronic inflammation. Charts were reviewed for clinical outcomes including development of acute pouchitis, chronic pouchitis, biologic or small molecule initiation, hospitalizations, and surgery. Predictors of outcomes were analyzed using univariable and multivariable logistic and Cox regression. Results A total of 167 patients undergoing surveillance pouchoscopy were included. Polymorphonuclear leukocytes (odds ratio [OR], 1.67), ulceration and erosion (OR, 2.44), chronic inflammation (OR, 1.97), and crypt distortion (OR, 1.89) were associated with future biologic or small molecule initiation for chronic pouchitis. Loss of goblet cells was associated with development of chronic pouchitis (OR, 4.65). Pyloric gland metaplasia was associated with hospitalizations (OR, 5.24). No histologic variables were predictive of development of acute pouchitis or surgery. In an exploratory subgroup analysis of new IPAA (<1 year), loss of goblet cells was associated with acute pouchitis (OR, 14.86) and chronic pouchitis (OR, 12.56). Pyloric gland metaplasia was again associated with hospitalizations (OR, 13.99). Conclusions Histologic findings may be predictive of IPAA outcomes. Pathologists should incorporate key histologic variables into pouchoscopy pathology reports. Clinicians may need to more closely monitor IPAA patients with significant histologic findings.