Content area
Full Text
THROMBOPHILIA AND VENOUS THROMBOEMBOLISM
Thrombophilia is the term now used to describe predisposition to increased risk of venous and occasionally arterial thromboembolism due to hematological abnormalities.1-4 It can be a multifactorial disorder where congenital defects of anticoagulant or procoagulant factors may be combined with acquired hematological abnormalities.1,2 It should be considered in patients with a documented unexplained thrombotic episode or a positive family history.1,2,5,6
The aim of this document is to provide guidelines for investigation and management of patients with thrombophilia in the presence or absence of venous thromboembolism (VTE).
[Int Angiol 2005;24:1-26]
Venous thromboembolism: magnitude of the problem
VTE causing deep vein thrombosis (DVT) or pulmonary embolism (PE) is a major international health problem. At one extreme, PE can be fatal. In North America and Europe, the annual incidence is approximately 160 per 100 000 for DVT, 20 per 100 000 for symptomatic non fatal PE and 50 per 100 000 for fatal autopsy-detected PE.7-11 Often, overlooked is the fact that DVT can lead to post-thrombotic deep venous reflux or obstruction causing leg skin changes and ulceration, which adversely impacts on quality of life and escalates health care costs. The prevalence of venous ulceration is at least 300 per 100 000 and approximately 25% are due to DVT.12, 13 The annual cost resulting from venous ulceration has been estimated to be £ 400 to 600 million for the UK 14, 15 and more than $ 1 billion for the US.16, 17
VTE should be an appealing target for maximum prophylaxis, but it has been difficult to achieve consensus on its prevention and management. The diagnosis can be difficult and elusive since many venous thromboembolic events are not detected clinically, either because they are asymptomatic or they cause symptoms attributed to other conditions. It is important for medical practitioners to understand the epidemiology, recognize high-risk groups, be familiar with new diagnostic methods,18,19 and follow the ever-changing approach to prophylaxis and therapy.20
Virchow s triad of factors that predispose to VTE are venous stasis, alterations in blood constituents, and changes in the endothelium; these are as true today as when postulated in the 19th century. It is often necessary for at least two of these changes to coexist for VTE to occur. Principal clinical...