Postoperative venous thromboembolism rates vary significantly after different types of major abdominal operations

Background: Venous thrombolism (VTE) is a significant cause of morbidity for surgical patients. Comparative risk across major procedures is unknown. Methods: Retrospective analysis of the Nationwide Inpatient Sample (2001-2005) was conducted. Eight surgeries were identified: bariatric surgery, colorectal surgery, esophagectomy, gastrectomy, hepatectomy, nephrectomy, pancreatectomy, splenectomy. Age < 18, patients with multiple major surgeries, and those admitted for treatment of VTE were excluded. Primary outcome was occurrence of VTE. Independent variables included age, gender, race, Charlson score, hospital teaching status, elective procedures, cancer/metastasis, trauma, and year. Results: Patients, 375,748, were identified, 5,773 (1.54%) with VTE. Overall death rate was 3.97%, but 13.34% after VTE. Unadjusted rate (0.35%) and adjusted risk for VTE were lowest among bariatric patients. On multivariate analysis, highest risk for VTE was splenectomy (odds ratio 2.69, 95% CI 2.03-3.56). Odds ratio of in-hospital mortality following VTE was 1.84 (1.65-2.05), associated with excess stay of 10.88days and $9,612 excess charges, translating into $55 million/year nationwide. Conclusion: Highest risk for VTE was associated with splenectomy, lowest risk with bariatric surgery. Since bariatric patients are known to have greater risk for this complication, these findings may reflect better awareness/prophylaxis. Further studies are necessary to quantify effect of best-practice guidelines on prevention of this costly complication.