Clinical relevance of distal deep vein thrombosis
Marc Righini (1), Samuel Paris (1), Grégoire Le Gal (4), Jean-Pierre Laroche (3), Arnaud Perrier (2), Henri Bounameaux (1)
(1) Division of Angiology and Hemostasis, (2) Division of Internal General Medicine, Geneva University Hospital, Geneva, Switzerland (3) Department of Vascular Medicine, University Hospital, Montpellier, France (4) Department of Internal Medicine and Ch
Summary The standard diagnostic approach of suspected deep veinthrombosis (DVT) is serial lower limb compression ultrasound(CUS) of proximal veins.Although it only assesses the proximalveins, withholding anticoagulant treatment in patients with anegative CUS on day one and after one week has been proven tobe safe. However, in many centres, distal DVT is systematicallyscreened for and treated by anticoagulants.The objectives of thereview were 1) to evaluate the rate of extension of distal DVTsto proximal veins 2) to compare the safety of proximal limitedCUS versus single complete CUS. We performed a MEDLINEsearch covering the period from January 1983 to January 2005by using the key-words “calf vein thrombosis”,“distal thrombosis”and “compression ultrasonography”. English, German andFrench language original studies were retrieved. Moreover, referencesof retrieved articles were screened in order to detectmissed pertinent articles. We pooled data of management studies where proximal or complete (i.e. proximal and distal)CUS were used, respectively. Studies evaluating CUS limited tothe proximal veins showed a good safety profile with a pooledestimate of the 3-month thromboembolic rate of 0.6% (95% CI:0.4-0.9%) in patients in whom anticoagulation was withheld.Studies using proximal and distal CUS showed a similar pooledestimate of the 3-month thromboembolic rate (0.4%, 95% CI:0.1-0.6%) but distal DVT accounted for as many as 50% of alldiagnosed DVTs in those series.Therefore, searching for distalDVT potentially doubles the number of patients given anticoagulanttherapy and entails a risk of over-treatment. Datasuggesting that anticoagulation is indicated for distal DVT arelimited, and realizing distal CUS entails a risk of over-treatment.There is an urgent need for randomised trials assessing the usefulnessof anticoagulant treatment in distal DVT.