Extended venous thromboembolism chemoprophylaxis after pancreas surgery for cancer: Does the subcutaneous needle move the needle?

BACKGROUND: Twenty-eight days of extended chemoprophylaxis is recommended for patients undergoing pancreatectomy for malignancy. We hypothesized that the current strategy of extended venous thrombotic event chemoprophylaxis is ineffective in reducing postoperative venous thrombotic events. METHODS: This was a single-institution retrospective review of pancreatectomy patients with cancer. Symptomatic postoperative venous thrombotic event (pulmonary embolism, deep vein thrombosis, and mesenteric vein thrombosis) rates at 90 days were evaluated. Perioperative variables were in accordance with National Surgical Quality Improvement Program and International Study Group for Pancreatic Surgery definitions. Univariable and multivariable analyses were performed. Institutional practice for extended venous thrombotic event prophylaxis is 28 days of once-daily subcutaneous enoxaparin. RESULTS: Between 2013 and 2024, 1,667 patients underwent pancreatectomy. The mean age was 67 ± 10.7 years, with a mean body mass index of 27 ± 5.8. Most operations were pancreatic head resections (1,303 [78%]). The incidence of postoperative thrombotic events was 115 (6.9%), deep vein thrombosis or pulmonary embolism was 63 (3.8%), and mesenteric vein thrombosis (portal vein/superior mesenteric vein/splenic vein) was 58 (3.5%). Sixty-nine (60%) were diagnosed with venous thrombotic event after discharge. Excluding inpatient venous thrombotic events, comparing venous thrombotic event rates between patients with and without chemoprophylaxis, there was no difference in rates of any thrombus, deep vein thrombosis/pulmonary embolism, mesenteric vein thrombosis, or clinically significant bleeding events. Among patients discharged with extended venous thrombotic event prophylaxis, multivariable logistic regression found increasing body mass index as a significant risk factor for venous thrombotic event after hospital discharge (odds ratio, 1.10; 95% confidence interval, 1.05-1.15; P ≤ .001). CONCLUSION: Routine chemoprophylaxis after pancreatectomy for cancer did not reduce rates of deep vein thrombosis, pulmonary embolism, or mesenteric vein thrombosis. Among patients discharged on extended prophylaxis, a higher body mass index was associated with an increased venous thrombotic event risk. This suggests that current prophylaxis strategies may be inadequate, and future strategies may utilize weight-based dosing for prophylaxis regimens.