Sonographic diagnosis of thrombosis of the calf muscle veins and the risk of pulmonary embolism

Aim: To determine the frequency of deep vein thrombosis in the veins of the calf muscles. The risk of embolism in relation to the localisation of thro mbosis was also evaluated. Method: 357 consecutive patients submitted for c olour Doppler sonography of the lower extremities were prospectively examin ed for deep vein thrombosis (DVT). Both axial and muscular calf veins were investigated. 184 of these patients underwent additional investigation for pulmonary embolism. Results: Diagnosis of DVT was made by means of colour D oppler sonography in 179 patients. Soleal veins (n = 88), peroneal veins (n = 84), the popliteal vein (n = 69), and the superficial femoral vein (n = 53) were the most common sites of thrombosis. Thrombosis of the gastrocnemi al veins (n = 49) occurred less frequently. 85 patients (47% of all patient s having DVT) showed isolated calf vein thrombosis, in 45 patients (25%) th e gastrocnemial and/or soleal veins were the only site of thrombosis. 60% o f patients with symptomatic DVT also had pulmonary embolism. The embolic fr equency for isolated calf vein thrombosis and muscular calf vein thrombosis was 48% and 50%, respectively. Conclusion: The veins of the calf muscles a re a common site of acute DVT and a source of pulmonary embolism. They shou ld always be investigated in patients with suspected DVT of the calf, and i n patients with pulmonary embolism.