Prophylaxis of Thrombosis With Implantable Devices for Central Venous Access in Cancer Patients

Inclusion Criteria: * First line chemotherapy for solid tumor with: * Metastatic disease or * Involved nodes or * Unresectable tumor * Indication for Implantable device for central venous access * Potential survival \> 3 months * ECOG performance status 0 to 2 (WHO) * Age between 18 and 75 years. * Social security guaranteed * Normal laboratory assessments (platelets\> 100000/mm3, TP 60%, spontaneous TCA with M/T\<1.5, TGO and TGP \< 2xN, serum creatinin\<120µmol/l) * Informed consent signed Exclusion Criteria: * Inability to understand informed consent or interfering with compliance for treatment or protocol Anti-coagulant treatment -related criteria * Acute infectious endocarditis * History related with heparin allergy or thrombopenia due to heparin * Uncontrolled high blood pressure (systolic blood pressure \>180 mm Hg and/or diastolic blood pressure \>110 mm Hg) * Hemorrhagic syndrome ongoing * Patient with platelet inhibitors treatment * Chronic, daily treatment with anti-coagulant therapy (LMWH or AVK), use as preventive or curative level * Patient with liver failure (TP\<60%) or renal insufficiency (creatinin clearance\< 20 ml/mn) * Women with pregnancy and lactating Pathology-related criteria * deep venous thrombosis history or pulmonary embolism (\< 6 months) * Clinical suspicious of brain metastasis