A review of venous collaterals in inferior vena cava obstruction

The purpose of this study was to review venous collateralization resulting from inferior vena cava obstruction. The elements responsible for the extent and distribution of venous collaterals in inferior vena cava obstruction and whether or not the obstructive lesion involves tributaries of the inferior vena cava. Common etiologies of inferior vena cava obstruction include extensions of iliofemoral vein thrombi, thrombosis from intraluminal tumors or following trauma, and external compression. The anatomy of the venous collateral systems may be divided into deep and superficial networks, each of which is composed of systems of primary or secondary clinical significance, as defined by the degree of restoration of adequate venous return and the extent of visceral venous decompression. The most common obstructions of the inferior vena cava involve the lower third of the vessel. The azygos-hemiazygos and vertebral venous plexus systems play the most significant roles, while the superficial systems are less prominently involved. In upper level inferior vena cava obstruction, reestablishment of venous circulation is less developed, which usually leads to a poorer clinical outcome. © 1992 Wiley-Liss, Inc.