[Diagnosis of deep venous thrombosis]

Deep venous thrombosis (DVT) is often difficult to diagnose based on objective data alone (sensitivity 60-66%, specificity 20-72%, according to a number of studies) and this leads to the possible misuse of instrumental tests. It is important to establish standard clinical protocols to select those cases that call for further diagnostic tests. The classic gold standard, phlebography, is invasive, expensive, not always available, and occasionally inadequate or risky. Non-invasive diagnostic methods (Doppler, plethysmography, eco-Doppler) is sufficiently sensitive for proximal venous occlusions, but not for distal occlusion. D-dimer assay is an accurate means of excluding the presence of DVT, but should be associated with instrumental diagnosis to increase its accuracy in asymptomatic patients. In order to optimize the use of clinical and anamnestic data, the authors propose measuring standard parameters using a scoring system. In cases with a score of > 3 (high risk) the frequency of DVT confirmed by phlebography is 75% in medium-risk patients the frequency is 17% low risk patients reveal a frequency of 3%. Patients with a medium- to high risk (overall score > 1) and positive Doppler for DVT, the diagnosis is reasonably certain and treatment may be started. In low-risk patients (score < or = 0) and negative Doppler, the diagnosis of DVT is highly improbable and no therapy is indicated. Discordant results between the clinical and Doppler tests underline the need for further instrumental tests.