Patients with inflammatory bowel disease (IBD) may be at a greater risk for postoperative venous thromboembolism (VTE) at least 30 days after surgery for colorectal cancer, according to the results of a large, retrospective study presented at the 2026 Digestive Disease Week Conference.
“These findings highlight a predominantly delayed postoperative VTE risk pattern in [patients with] IBD and may help guide postoperative monitoring and decisions regarding the duration and focus of thromboprophylaxis,” the study authors wrote in their presentation abstract.
“For patients with IBD who get bowel surgery, especially for cancer, it gives us a heightened awareness,” stated study coauthor Miguel Regueiro, MD, Chief of the Digestive Disease Institute at Cleveland Clinic. “We should be telling these patients not to ignore warning signs like shortness of breath or swelling in the legs, especially if it’s only in one leg.”
Background and Study Methods
The researchers sought to explore the timing and pattern of postoperative VTE following colorectal cancer surgery for patients with IBD. They performed a collaborative network propensity-matched cohort study, gathering patient data from the TriNetX network of adult patients undergoing first colorectal cancer surgery, including total colectomy, subtotal/hemicolectomy, or ileal pouch–anal anastomosis.
Included patients with IBD had at least two preoperative diagnoses of ulcerative colitis or Crohn's disease, while patients in the control group did not have IBD. Patients in both groups were matched 1:1 with balanced demographics, comorbidities, cancer characteristics, and medication exposures.
The primary outcome measures were deep vein thrombosis, pulmonary embolism, combined VTE, and a composite of VTE and mortality, which were each assessed at 0–30, 31–90, and 91–365 days.
Key Findings
Patients with IBD who developed postoperative VTE were more likely to be older, male, White, have proximal colon tumors, and receiving anticoagulant or antiplatelet therapy. Additionally, these patients had higher rates of obesity, diabetes, chronic pulmonary disease, atrial fibrillation, prior VTE, and thrombophilia.
After matching, there was a total of 24,050 patients, amounting to 12,025 in each group.
Rates of combined VTE were similar between the IBD and control groups in the 0–30 day time period after surgery, at 6.2% and 5.4%, respectively (adjusted odds ratio [aOR] = 1.16; P = .39).
For the 31–90 day period, patients with IBD were significantly more likely than patients in the control group to develop VTE (aOR = 1.58; P = .020), which was primarily driven by an increased risk of deep vein thrombosis (aOR = 1.89; P = .0078); the risk of pulmonary embolism was similar in both groups (aOR = 1.26; P = .452).
For the 91–365 day period after surgery, the risk of combined VTE was still elevated for patients with IBD (aOR = 1.58; P = .0095), as well as for risks of deep vein thrombosis (aOR = 1.54; P = .030) and pulmonary embolism (aOR = 1.79; P = .033).
Rates of mortality did not show significant differences between any postoperative time periods.
By multivariable regression, older age, obesity, diabetes, atrial fibrillation, prior VTE, thrombophilia, metastatic disease, proximal tumor location, and anticoagulant or antiplatelet use were all independent predictors of VTE following colorectal cancer surgery.
DISCLOSURES: For full disclosures of the study authors, visit sciencedirect.com.
