ABNORMAL PRE-OPERATIVE ANORECTAL MANOMETRY IS ASSOCIATED WITH INFLAMMATION OF THE RECTAL CUFF IN IPAA PATIENTS BUT NOT ENDOSCOPIC INFLAMMATORY POUCH DISEASE

Abstract BACKGROUND Patients undergoing ileal pouch-anal anastomosis (IPAA) for inflammatory bowel disease (IBD) may experience post-operative inflammation of the ileal pouch (pouchitis) or rectal cuff (cuffitis). Post-operative pelvic floor dysfunction has previously been associated with inflammatory pouch outcomes. Furthermore, our recent pilot study identified an association between abnormal pre-operative anorectal manometry (ARM) and post-operative pouch ulceration and cuffitis; however, we did not adjust for covariates due to sample size and did not assess composite outcomes of pouch inflammation. In this expanded study, we aimed to further assess whether pre-operative pelvic floor dysfunction defined by abnormal anal sphincter function on ARM is associated with post-operative pouch and cuff inflammation. METHODS This historical cohort study assessed IBD patients who underwent pre-operative ARM with completion of their IPAA surgical series January 2009 - December 2024. Patients were divided into two groups—normal versus abnormal pelvic floor function—based on ARM prior to completion of IPAA surgical series. The two primary outcomes were a composite outcome of endoscopic inflammatory pouch diseases (EIPD) and an outcome of rectal cuffitis after the peri-operative period. Secondary outcomes included individual components of the composite primary outcome. Multivariable logistic regression was used to assess primary outcomes (EIPD and cuffitis) while controlling for covariates. RESULTS A total of 179 patients were included in this study, 46 (25.7%) in the abnormal ARM group and 133 (74.3%) in the normal ARM group. Cohorts had similar demographic and pre-operative characteristics except for gender; there was a higher proportion of females in the abnormal ARM group (63.0% versus 45.1%; p = 0.036). Median follow-up time after IPAA was 2.88 years for the abnormal ARM group and 3.61 years for the normal ARM group (p = 0.347). In total, 72 (40.2%) patients developed cuffitis and 61 (34.1%) developed EIPD. In multivariable regression, patients with abnormal ARM had a higher risk of cuffitis (OR 2.17; 95% CI 1.05-4.35; p = 0.037; Table 1) but not EIPD (p = 0.427). Secondary outcomes were similar between groups apart from diffuse pouch inflammation, which was more common in patients with abnormal ARM (p = 0.024; Table 2). DISCUSSION Abnormal pre-operative ARM was associated with post-operative cuffitis in IPAA patients after adjusting for potential confounders, which aligns with results from our pilot study. However, there was no significant association with EIPD. ARM prior to completion of IPAA surgical series could potentially be utilized to predict some inflammatory complications in select patients, but the specific associations between pre-operative ARM and endoscopic outcomes as well as the underlying mechanisms merit further investigation.