Management of venous thromboembolism--controversies and the future.

Despite the availability of comprehensive evidence-based guidelines there are difficult and controversial areas in the management of venous thromboembolism. Institutions and even countries disagree on the importance of calf vein thrombosis, with some rigorously detecting and treating it and others deliberately not looking for it. The need to treat proximal deep vein thrombosis and pulmonary embolism is accepted but which patients with an unprovoked first event should have long-term anticoagulation has become a difficult clinical decision. We are uncertain how to reduce the incidence of post-thrombotic syndrome seen in a substantial number of patients. How hard to look for an undiagnosed underlying cancer has become a contentious issue particularly in the United Kingdom following the recent publication of a guideline from the National Institute for Health and Clinical Excellence. Whilst we are wrestling with these dilemmas we are entering an era of new anticoagulants and have to solve the logistical problems of introducing them into clinical practice despite cost pressures. These issues will be explored in this review.