[Normal and pathological compression of the venous system]

A study of 190 female patients was carried out at the level of the solar ring, the crural arch, the left ilio-caval junction and the vena cava ring of the diaphragm, in order to determine whether these represent, per se, critical areas, which may cause compression and hinder the venous return as a result of the narrowing and the poor distention of their structures. Sonotomography alone or associated with the pulsed Doppler were selected for this study. The action of the various components (bone, muscle, tendon, vessels and nodes) on the venous system is each region, was analyzed. The overall results have demonstrated two types of compression: a) intermittent, b) permanent. The former is considered as a hemokinetic mechanism, especially at the level of the solar arch and the vena cava ring of the diaphragm. They represent a major element of the pump and the vis-a front respectively. The permanent compression was considered as pathological, and could be related to a venous displacement occurring as an adaptation mechanism to the extrinsic compression. The data obtained in all four regions, have demonstrated that their various components are in a precarious balance, but they do not constitute a true obstacle to the venous return, even if in some postures or respiratory movements they may cause an intermittent venous compression.