Do patients with inflammatory bowel disease have a higher postoperative risk of venous thromboembolism or do they undergo more high-risk operations?

Objective:To determine the relative or combined effects of Crohn disease (CD) and ulcerative colitis (UC) and the operation performed on postoperative venous thromboembolism (VTE) to better guide recommendations on extended VTE prophylaxis.Summary Background Data:There is growing evidence to suggest patients with inflammatory bowel disease have an increased risk of postoperative VTE, but prior studies have not accounted for the operation performed nor acknowledged differences between CD and UC.Methods:The American College of Surgeons National Surgical Quality Improvement Project database from 2005 to 2016 was queried for patients with a diagnosis of CD, UC, malignancy, or benign disease (diverticular disease, Clostridium difficile) undergoing major abdominal surgery. Operations with a VTE rate >3% were designated high risk. Operation-specific univariate and multivariable logistic regression analyses were conducted.Results:A total of 231,718 operations were analyzed with 4426 patients experiencing a VTE (1.9%). The overall rate of VTE ranged widely based on the operation performed from 0.7% for enterostomy closure to 5.3% for open subtotal colectomy. Seven operations met our threshold of 3% to be considered high risk. For each operation, postoperative VTE rates were similar regardless of diagnostic indication when performed in the elective setting. However, when performed emergently, the same operations had significantly higher VTE rates. Compared with the malignancy and benign disease groups, neither CD nor UC was associated with increased odds of VTE after any operation.Conclusions:Postoperative VTE risk varies widely by the operation performed, and a diagnostic indication of CD or UC does not play a role. Extended duration VTE prophylaxis should be considered in all patients undergoing high-risk operations, regardless of their underlying diagnosis.