Are IBD Patients Underscored when Determining Postoperative VTE Risk?

Background: Patients with inflammatory bowel disease (IBD) have an increased risk of venous thromboembolism (VTE) following colorectal surgery and there is currently no consensus on post-surgical VTE prevention or specific VTE risk assessment tools. We sought to evaluate VTE risk after colorectal surgery and determine if known risk factors used in risk assessment tools adequate correlate with VTE risk in IBD patients.

Methods: Retrospective cohort study using the National Surgical Quality Improvement Project (NSQIP) Participant User File from 2010 to 2018.

Results: A total of 27,679 patients were included; 19,015 (68.7%) had Crohn's disease (CD) and 8664 (31.3%) ulcerative colitis (UC). Of these, 16,749 (60.5%) underwent abdominopelvic procedures, 10,178 (36.8%) complex pelvic procedures, and 752 (2.7%) small bowel operations. The overall VTE rate was 2.3%. The VTE rate in patients with CD and UC was 1.8% and 3.6% (p < 0.001) respectively. Overall median time to VTE was 9 days after surgery. VTE rate was highest in patients who underwent complex pelvic procedures (3.6%; 361/10,178). A risk score was calculated using 16/40 available variables from the Caprini VTE Risk Assessment tool; risk score ranged from 3 to 12 points. Most patients that developed a VTE had a score between 3 and 5 points (75.6%), and only 24.5% had a score of 6 or higher. Patients with higher risk scores did not have a higher VTE incidence.

Conclusion: Post-surgical VTE rates are high in IBD patients. Over half of the events occurred following discharge and in patients with an apparent low-risk score. Additional studies are warranted to define a recommended postoperative VTE prophylaxis regimen for patients with IBD.