Venous thromboembolism in abdominal cancer surgery.

Venous thromboembolism (VTE) is recognized as a serious complication in both surgical and non-surgical patients. Cancer, particularly adenocarcinoma developing in the digestive organs, is one of the most potent risk factors for VTE, as first described by Trousseau in 1865. Cell membrane microparticles shedding from cancer cells play a critical role in venous clot formation through tissue factor (TF)-mediated activation of the coagulation system. Since recent prospective studies have demonstrated that VTE risk in Japanese surgical patients is comparable to that in Caucasians, perioperative thromboprophylaxis with anticoagulants is now considered essential in patients undergoing abdominal cancer surgery, in addition to mechanical thromboprophylaxis. Recent multi-center studies have also shown the efficacy and safety of enoxaparin, a low molecular weight heparin (LMWH), and fondaparinux, a synthetic Xa inhibitor, in VTE prevention after abdominal cancer surgery. Anticoagulants like LMWH are expected to exert not only thromboprophylactic but also antineoplastic effects.