Thrombotic complications of polycythemia. The venous and arterial risk factors.

Arterial and venous thrombotic complications have being increasingly recognized as a major cause of mortality and morbidity in polycythemia vera. The risk can be increased with the treatment. Actually, we can not precisely evaluate the risk of previous venous and arterial lesions, however we have non invasive techniques that permit an accurate evaluation of the vascular bed in patients without recent thrombotic events. The ratio cost-efficacy of the vascular explorations has to be discussed according to the risk factors. In patients with a recent arterial thrombotic event, extensive vascular investigations are mandatory.