Deep Vein Thrombosis

Abstract

Venous thromboembolism (VTE) comprises deep vein thrombosis (DVT) and pulmonary embolism (PE). DVT occurs at an incidence of 1/1,000 and risk factors include immobilization, hospitalization, surgery, thrombophilia and positive family history, cancer, pregnancy, and other hormonal effects. Commonly, clinical signs and symptoms for DVT are unreliable, especially in hospitalized patients, but the clinical assessment of the pretest probability, for example, with the Wells score, is an important component in the diagnostic algorithm, where compression ultrasound also plays a central role. Treatment of DVT aims to acutely prevent PE and short-term and long-term VTE recurrence and to avoid the long-term complication of the postthrombotic syndrome (PTS). The immediate, sufficient, and uninterrupted anticoagulation is the most important therapeutic modality in the treatment of DVT and is achieved with subcutaneous LMWH and overlapping use of vitamin K antagonists (VKA) as standard treatment. After the initial anticoagulation, a long-term anticoagulation is used to prevent recurrences. The duration of anticoagulation is determined by balancing the risk of recurrence against the risk for bleeding with VKA and also considering the patient’s preference. In patients in whom anticoagulation could be discontinued, aspirin was shown to reduce the risk of VTE recurrence by one third compared to placebo. Novel (non-vitamin K antagonist) oral anticoagulants (NOACs) have been compared to the standard treatment in several large phase 3 trials in patients with VTE. NOACs, which are given at a fixed dose without coagulation monitoring, have been shown to be non-inferior to standard treatment with respect to recurrent VTE, but have consistently shown lower bleeding rates, in particular less intracerebral hemorrhages. Practical issues of NOACs have to be observed, including their label and dosing regimen, their effect on coagulation assays, periprocedural management, and management of bleeding complications. Long-term use of compression stockings has been shown to reduce the PTS in several independent trials and meta-analyses, but new interventional techniques are being introduced in order to further reduce the PTS, particularly in iliac vein thrombosis. Cancer patients suffering from VTE require special attention, as both their bleeding and recurrence risk is increased, and LMWH has been shown to be more effective than VKA. VKA and NOACs should also be avoided in pregnant women suffering from VTE; VKA can cause embryopathy and an increased risk of bleeding both for mother and child. Thus, LMWH is the anticoagulant treatment of choice in pregnant women. Upper-extremity deep vein thrombosis (UEDVT) has a somewhat different pathophysiology and complication rates compared to DVT of the lower extremities. Therefore, diagnostic and therapeutic management of UEDVT may differ from the standard treatment of DVT.