A novel scoring system for predicting postoperative venous thromboembolic complications in patients after open aortic surgery

Background: Although the overall incidence of venous thromboembolism (VTE) after open aortic surgery is low, it is not known whether specific factors can place patients at increased risk for this complication. The goal of our study was to identify patient and procedure characteristics that are associated with increased VTE risk after aortic surgery and that might therefore merit aggressive prophylaxis against this complication. Study Design: All patients in the National Surgical Quality Improvement Program 2005-2009 Participant Use Data Files who underwent open aortic surgery for aneurysmal disease were included for analysis. Forward stepwise multivariate logistic regression analysis was used to identify patient and procedure characteristics associated with an increased risk of postoperative VTE events. Separate multivariate models were also used to predict which of 18 non-VTE postoperative complications might also be associated with an increased incidence of subsequent VTE, with adjustment for multiple comparisons. Results: Postoperative VTE developed in 147 of 6,035 patients (2.4%) and in 60.5%, this complication developed after a non-VTE complication. Nine perioperative variables were found to be significantly associated with subsequent VTE on multivariate regression analysis. Patients with ≥3 of these risk factors were found to have a 3- to 4-fold higher incidence of postoperative VTE. Conclusions: Our analysis identifies a group of patients who are at increased risk of postoperative VTE complications developing after open aortic surgery. Aggressive postoperative chemical or mechanical prophylaxis should be considered in these patients when appropriate.