S1185 Non-Fistulizing Perianal Crohn's Disease in a Population-Based Cohort

Abstract

Background and aims: We sought to update the cumulative probability of surgery in Crohn's disease in a population-based cohort, and to identify baseline factors associated with need for surgery. Methods: Using the resources of the Rochester Epidemiology Project, the medical records of 310 incident cases of Crohn's disease from Olmsted County, Minnesota, diagnosed between 1970 and 2004, were reviewed through March 2009. Major abdominal surgery was defined as any surgery except perianal surgery or endoscopic dilation. Cumulative incidence was estimated using the Kaplan-Meier method, and associations between baseline factors and time to first event were assessed using proportional hazards regression and expressed as hazard ratios (HR) with 95% confidence intervals (95% CI). Results: Median follow-up per patient (pt) in this cohort was 11.8 years (yrs) (range, 0.1-39 yrs). A total of 152 pts (49%) underwent at least one major abdominal surgery, 65 pts (21%) underwent at least two major abdominal surgeries, and 32 (10%) underwent at least three major abdominal surgeries. The first major abdominal surgery was an ileal or ileocecal resection in 110 out of 152 (72.4%) pts. The mean number of major abdominal surgeries was 0.25 (+/1.32) per yr of follow-up. See table for cumulative probabilities (%) with 95% CI of various surgical endpoints at 5, 10, 20, and 30 years. Baseline factors significantly associated with time to first major abdominal surgery were ileocolonic (HR relative to colonic, 3.8; 95% CI, 2.3-6.1), small bowel (HR, 4.3; 95% CI, 2.6-6.9), and upper gastrointestinal (HR, 5.7; 95% CI, 2.3-14) disease; and penetrating (HR, 8.6; 95% CI, 5.8-12.8) and stricturing (HR, 9.4; 95%CI, 5.1-17.1) complications at the time of diagnosis. Conclusion: The cumulative risk of major abdominal surgery in this population-based cohort of Crohn's disease exceeded 60% after 30 years of disease, and many pts required second or third surgeries. Non-colonic disease extent and complicated disease at diagnosis were significantly associated with need for major abdominal surgery. Knowledge of these factors may be useful when developing disease modification trials. Cumulative Probability (%) With 95% CI