Two Novel Risk Factors for Postoperative Venous Thromboembolism: A Reconsideration of Standard Risk Assessment and Prophylaxis

BackgroundPostoperative venous thromboembolism (VTE) is usually preventable with adequate prophylaxis. In an institutional study, patients with emergency operations (EO), multiple operations (MO), and perioperative sepsis (PS) were more likely to develop VTE despite standard prophylaxis.MethodsGeneral surgery patients in the NSQIP database from 2011 to 2014 were stratified into VTE and non-VTE groups, and statistical analyses were performed.ResultsAmong 1,610,086 patients, 13,673 (0.8%) were diagnosed with VTE. The VTE odds ratios for patients with EO, MO and PS were 1.4 (95%CI:1.3–1.5), 1.9 (95%CI:1.7–2.0), and 2.4 (95%CI:2.2–2.5), respectively. VTE odds ratios increased with concurrence of two factors (EO+PS: 2.0 (95%CI:1.9–2.2)) (EO+MO: 2.3 (95%CI:1.9–2.7)) (MO+PS: 2.5 (95%CI:2.2–2.7)) and further still for patients with all three factors (2.7, 95%CI:2.4–3.0).ConclusionGeneral surgery patients with EO, MO, or PS have a greater likelihood of developing postoperative VTE. These factors are not necessarily captured in contemporary risk assessment models that guide chemoprophylaxis, and so these high-risk patients may receive insufficient prophylaxis.