In this report, we review the anatomical features of the crural veins and the importance of the soleal vein and its drainage veins for thrombi formation and propagation. The result of our investigation of 120 legs of 60 autopsy cases with fatal pulmonary thromboembolism showed that the soleal vein was the most frequent site of deep vein thrombosis, both for fresh and for organized thrombi. Furthermore, the detection rate of thrombi, both fresh and organized, showed that the most common site was in the soleal vein and then decreased progressively according to the drainage route of the soleal vein. Anatomical characteristics and physiological mechanisms play a major role in the occurrence and propagation of venous thrombi. Thus, an understanding of these features is essential for effective prophylaxis of venous thromboembolism.
