[Use of oral anticoagulants to prevent central venous catheter-related thrombosis in hemodialysis].

Central venous catheters (CVCs) are fundamental in the management of hemodialysis. Despite major efforts to provide arteriovenous access, their use is increasing in dialysis units worldwide. The presence of a catheter inside a vein increases the risk of thrombosis, both within the catheter and in the vein. Thrombosis is a serious complication because it can lead to inefficient dialysis, alter the venous circulation, and facilitate infections. In this article, questions regarding anticoagulant treatment in dialysis patients with CVCs are explored and specific suggestions offered for clinical practice, based on the evidence available and the personal experience of the authors. Should CVC-induced thrombosis be treated? The duration, site and extension of the thrombotic complication should be assessed. If thrombosis is recent and symptomatic, heparin treatment followed by oral anticoagulant therapy is suggested. Is oral anticoagulant therapy useful for primary prevention of thrombosis, both within the CVC and the vein where the catheter is inserted? The available evidence favoring the use of oral anticoagulant therapy is not entirely convincing. At any rate, before such treatment is started the balance between the antithrombotic efficacy and the possible side effects should be carefully weighed. Is oral anticoagulant therapy useful for secondary prevention of CVC thrombosis? If a permanent CVC is in place and its position is correct and the blood flow < 250 mL/min, we recommend - before replacing the CVC - thrombolytic treatment followed by oral anticoagulants, aiming at an INR target between 2 and 3. Are the side effects of oral anticoagulant therapy an issue? The use of anticoagulants in renal failure carries an increased risk of complications, in particular bleeding and vascular calcifications, which could annul the advantages derived from reduced thrombotic events. Before starting oral anticoagulant therapy we suggest to carefully evaluate if there are potential overall benefits and to pay attention to concomitant antiplatelet therapy.