Exploration of Pulmonary Embolic Sources in the Lower Limbs by Ultrasonography

Abstract

We demonstrate our method for detecting deep vein thrombosis in the lower limbs, the most frequent source of thrombosis, and we investigate the pathogenesis of critical pulmonary embolic sources. The subjects were 157 patients who underwent either pulmonary perfusion scanning or pulmonary angiography from 1987 to 1998. Unilateral thrombosis was found in 128 cases and bilateral thrombosis in 29. Among them, 42 patients exhibited symptomatic pulmonary embolism: 31 acute and 11 chronic. For exploration of deep vein thrombosis, the duplex with color Doppler was mainly used. Both sitting position and compression technique were necessary to diagnose calf vein thrombosis. Compared with the proximal occlusive levels and the incidence of symptomatic pulmonary embolism, the frequency of symptomatic pulmonary embolism was higher in the femoral vein or soleal vein than in other areas. In particular, most patients with chronic pulmonary embolism had bilateral soleal vein thrombosis. The frequency was significantly higher in bilateral thrombosis than in unilateral thrombosis. The duplex with color Doppler is the first choice of noninvasive testing methods to explore pulmonary embolic sources in the lower limbs. Both femoral vein thrombosis and soleal vein thrombosis are critical pulmonary embolic sources, and bilateral soleal vein thromboses may be a specific embolic source for chronic pulmonary embolism.