Oral anticoagulation in peripheral vascular surgery: how intense, for how long, or at all?

To evaluate the influence of postoperative pharmacotherapy (antiplatelet th erapy with acetylsalicylic acid (ASA) or oral anticoagulation) following va rious peripheral vascular surgical interventions (femoro-popliteal reconstr uction, femoro-popliteo-tibial venous bypass;) two clinical series of patie nts were analysed (A1-2) and we made the hypothesis that adjuvant therapy m ay be beneficial. Thereafter two clinical trials were carried out (B1-2), t o assess the value of postoperative antiaggregant and anticoagulant treatme nt. It was not possible to demonstrate any influence of ASA on improving pa tency at the iliaco-popliteal level or on patient survival. It was conclude d that the ASA dosage of 1500 mg daily was too high, and produced severe si de-effects, probably leading to insufficient patient compliance to therapy. In the B2 trial 130 patients received a femoro-popliteal above- or below-k nee rein bypass, and were assigned to the therapy group (n = 66) and treate d with anticoagulants or to the control group (n = 64) which received no th erapy. During the follow-up, for a maximum of 10 years, the probability of bypass function, limb salvage and patient survival were significantly in fa vour of the treatment. The described single centre clinical trial B-2 produ ced in accordance with other trials a level II evidence in favour of postop erative pharmacotherapy. Level 1 trials assessing the direct comparison of antiaggregant versus anticoagulant therapy are underway, but results are un available yet, similarly the results of the Antithrombotic Trialist's Colla boration (ATT) are currently unknown.