Risk of venous thromboembolism outweighs post-hepatectomy bleeding complications: analysis of 5651 National Surgical Quality Improvement Program patients

Background: Historically, liver surgeons have withheld venous thromboembolism (VTE) chemoprophylaxis due to perceived postoperative bleeding risk and theorized protective anticoagulation effects of a hepatectomy. The relationships between extent of hepatectomy, postoperative VTE and bleeding events were evaluated using the National Surgical Quality Improvement Program (NSQIP) database. Methods: From 2005 to 2009, all elective open hepatectomies were identified. Factors associated with 30-day rates of VTE, postoperative transfusions and returns to the operating room (ROR), were analysed. Results: The analysis included 5651 hepatectomies with 3376 (59.7%) partial, 585 (10.4%) left, 1134 (20.1%) right, and 556 (9.8%) extended. Complications included deep vein thrombosis (DVT) (1.93%), pulmonary embolism (PE) (1.31%), venous thromboembolism (VTE) (2.88%), postoperative transfusion (0.76%) and ROR with transfusion (0.44%). VTE increased with magnitude of hepatectomy (partial 2.13%, left 2.05%, right 4.15%, extended 5.76%; P < 0.001) and outnumbered bleeding events (P < 0.001). Other factors independently associated with VTE were aspartate aminotransferase (AST) =27 (P= 0.022), American Society of Anesthesiologists (ASA) class =3 (P < 0.001), operative time >222 min (P= 0.043), organ space infection (P < 0.001) and length of hospital stay =7 days (P= 0.004). VTE resulted in 30-day mortality of 7.4% vs. 2.3% with no VTE (P= 0.001). Conclusions: Contrary to the belief that transient postoperative liver insufficiency is protective, VTE increases with extent of hepatectomy. VTE exceeds major bleeding events and is strongly associated with mortality. These data support routine post-hepatectomy VTE chemoprophylaxis.