The Incidence and Risk Factors for Free Bowel Perforation in Patients With Crohnʼs disease

Abstract

Free bowel perforation (FP) in Crohn's disease (CD) can be lifethreatening especially among previously stable patients in clinical remission. The aim of this study was to investigate the incidence and risk factors of FP in CD patients. We analyzed the medical records of CD patients registered at the Asan Medical Center from March 1991 to May 2012. The incidence of FP, defined as a sudden spontaneous penetration of the bowel resulting in intestinal contents flowing into the peritoneal cavity, was investigated. Clinical characteristics were compared between patients who developed FP and those who did not, using the Cox proportional hazards analysis. Among 2385 patients registered, we included 1601 patients who had no previous history of intestinal perforation. There were 1136 (71.0%) males, and the mean age at diagnosis of CD was 24.8 years (standard deviation, 8.7 years). Over a median follow-up time of 5.5 years (interquartile range [IQR], 2.4—9.0), seventy three patients (4.6%) developed FP, with the incidence of 6.96 per 1000 person-years (95% confidence interval [CI], 5.50-8.81). Among FP cases, there were 55 males (75.3%), and the median age at FP was 21 years (IQR, 17—31 years). The disease locations were ileum in 23 (31.5%), ileocolon in 48 (65.8%) and colon in 2 (2.7%). The disease behaviors before FP were non-stricturing and non-penetrating in 8 (11.0%), structuring in 22 (30.1%), and penetrating in 43 (58.9%). On multivariable analysis, stricturing behavior (vs. non-stricturing and non-penetrating; hazard ratio [HR], 4.8; 95% CI, 2.0—11.5) and previous azathioprine use (HR, 0.2; 95% CI, 0.1—0.3) were independently associated with FP. The incidence of FP in a large cohort of Korean patients with CD was 4.6%. Patients with stricturing behavior seem to be at higher risk for future development of FP. Azathioprine use could possibly decrease the risk of FP.