[Pulmonary embolism and the level of thrombosis. A prospective study of 155 patients].

This study was designed to assess the risk of associated pulmonary embolism according to the level of deep venous thrombosis. From March 1992 to March 1994, 328 patients were referred to medical units for suspected deep venous thrombosis, with recent clinical signs, less than a week. Each patient underwent contrast venography and/or duplex ultrasounds of lower extremities, ventilation and perfusion lung scan within 48 hours and angiography in case of low or intermediate pulmonary embolism probability. Diagnosis of deep venous thrombosis was confirmed in 155 patients; location was distal in 41, proximal in 114; an associated pulmonary embolism was found in 66 patients (10 with distal, 56 with proximal deep venous thrombosis); odds ratio was 2.99 (95% Cl: 1.2-3.13). Significantly higher risk of associated pulmonary embolism when deep venous thrombosis involves proximal veins is confirmed, but as many as 10 out of 41 patients with distal thrombosis also had an associated embolism. Management of both distal and proximal deep venous thromboses appears identical.