Distinct predictors of pre- versus post-discharge venous thromboembolism after hepatectomy: Analysis of 7621 NSQIP patients

Objectives Hepatectomy patients are known to be at significant risk for venous thromboembolism (VTE), but previous studies have not differentiated pre- versus post-discharge events. This study was designed to evaluate the timing, rate and predictors of pre- ('early') versus post-discharge ('late') VTE. Methods All patients undergoing elective hepatectomy during 2005-2010 and recorded in the American College of Surgeons National Surgical Quality Improvement Program participant use file were identified. Perioperative factors associated with 30-day rates of early and late VTE were analysed. Results A total of 7621 patients underwent 4553 (59.7%) partial, 802 (10.5%) left, 1494 (19.6%) right and 772 (10.1%) extended hepatectomies. Event rates were 1.9% for deep venous thrombosis, 1.2% for pulmonary embolus and 2.8% for VTE. Of instances of VTE, 28.6% occurred post-discharge. The median time of presentation of late VTE was postoperative day 14. Multivariate analysis determined that early VTE was associated with age ≥75 years [odds ratio (OR) 1.92, P = 0.007], male gender (OR 1.87, P = 0.002), intraoperative transfusion (OR 2.49, P < 0.001), operative time of >240 min (OR 2.28, P < 0.001), organ space infection (OSI) (OR 2.60, P < 0.001), and return to operating room (ROR) (OR 3.25, P < 0.001). Late VTE was associated with operative time of >240 min (OR 2.35, P = 0.008), OSI (OR 3.78, P < 0.001) and ROR (OR 2.84, P = 0.011). Conclusions Late VTE events occur in patients with clearly identifiable intraoperative and postoperative risk factors. This provides a rationale for the selective use of post-discharge VTE chemoprophylaxis in high-risk patients.