Venous Thromboembolism After Surgery for Inflammatory Bowel Disease: Are There Modifiable Risk Factors? Data from ACS NSQIP

BACKGROUND: Although it is commonly reported that IBD patients are at increased risk for venous thromboembolic events, little real-world data exist regarding their postoperative incidence and related outcomes in everyday practice. OBJECTIVE: We aimed to identify the rate of venous thromboembolism and modifiable risk factors within a large cohort of surgical IBD patients. DESIGN: We performed a retrospective review of IBD patients who underwent colorectal procedures. PATIENTS: Patient data were obtained from the American College of Surgeons National Surgical Quality Improvement Program 2004 to 2010 Participant Use Data Files. MAIN OUTCOME MEASURES: The primary outcomes measured were short-term (30-day) postoperative venous thromboembolism (deep vein thrombosis and pulmonary embolism). Clinical variables were analyzed by univariate and multivariate analyses to identify modifiable risk factors for these events. RESULTS: A total of 10,431 operations were for Crohn's disease (52.1%) or ulcerative colitis (47.9%), and 242 (2.3%) venous thromboembolic events occurred (178 deep vein thromboses, 46 pulmonary embolisms, 18 both) for a combined rate of 1.4% in Crohn's disease and 3.3% in ulcerative colitis. Deep vein thrombosis and pulmonary embolism each occurred at a mean of 10.8 days postoperatively (range for each, 0-30 days). A multivariate model found that bleeding disorder, steroid use, anesthesia time, emergency surgery, hematocrit <37%, malnutrition, and functional status were potentially modifiable risk factors that remained associated (p < 0.05) with venous thromboembolism on regression analysis. Patients with thromboembolism had longer length of stay (18.8 vs 8.9 days), more complications (41% vs 18%), and a higher risk of death (4% vs 0.9%). LIMITATIONS: This study was limited by its retrospective design and its limited generalizability to nonparticipating hospitals. CONCLUSIONS: Inflammatory bowel disease patients are at increased risk for postoperative venous thromboembolism. Reducing preoperative anemia, steroid use, malnutrition, and anesthesia time may also reduce venous thromboembolism in this at-risk population. Risk-reducing, preventative strategies are needed in this at-risk population.