Long-Term Low-Molecular-Weight Heparin Versus Oral Anticoagulants in Deep Venous Thrombosis

Inclusion Criteria: * Consecutive, symptomatic patients with a first or recurrent episode of acute proximal-vein thrombosis of the lower limbs. * either sex and over 18 years of age * referred to the Vascular Surgery Department of the hospital * onset of symptoms less than 2 weeks * documented by compression ultrasonography, Exclusion Criteria: * received heparin, low-molecular-weight heparin or oral anticoagulant therapy for more than 2 days for the present disease * pulmonary embolism requiring thrombolytic therapy * Need of surgical thrombectomy or vena cava interruption * receiving oral anticoagulant treatment or antiplatelet agents for other conditions * contraindication to anticoagulant treatment (active bleeding, severe blood pressure or allergy to the study drugs) * platelet count lower than 100x103 /μl or hemoglobin concentration lower than 7 g/dl or history of heparin-associated thrombocytopenia * severe renal failure necessitating dialysis * pregnancy * lumbar puncture within the previous 24 hours