EFFICACY AND SAFETY OF ENOXAPARIN VERSUS UNFRACTIONATED HEPARIN FOR PREVENTION OF DEEP-VEIN THROMBOSIS IN ELECTIVE CANCER-SURGERY - A DOUBLE-BLIND RANDOMIZED MULTICENTER TRIAL WITH VENOGRAPHIC ASSESSMENT

Background Surgery for malignant disease carries a high risk of deep v ein thrombosis. The aim of this study was to evaluate the prophylactic effect of a low molecular weight heparin, enoxaparin, 40 mg once dail y, beginning 2 h before surgery, compared with that of unfractionated low-dose heparin three times daily. Methods Patients included were ove r 40 years of age and undergoing planned elective curative abdominal o r pelvic surgery for cancer. The study was designed as a prospective d ouble-blind randomized multicentre trial with participating department s from ten countries. Primary outcome was venous thromboembolism as de tected by mandatory bilateral venography or pulmonary scintigraphy. Fo llow-up was at 3 months. Results Some 1115 patients were randomized in to the study but venograms were inadequate in 460 (41.3 per cent). Of 631 evaluable patients, a total of 104 (16.5 per cent) developed throm boembolic complications. The frequency was 18.2 per cent in the hepari n group and 14.7 per cent in the enoxaparin group (95 per cent confide nce interval of the difference -9.2-2.3 per cent). There were no diffe rences in bleeding events or other complications. One patient in the h eparin group developed severe thrombocytopenia, There were no differen ces in mortality at either 30 days or 3 months. Conclusion Enoxaparin, 40 mg once daily, is as safe and effective as unfractionated heparin three times daily in preventing venous thromboembolism in patients und ergoing major elective surgery for abdominal or pelvic malignancy.