A morphological and functional study of the cavo-hepatic junction in the human.

The authors studied the morphological and structural aspects of the junctions between the hepatic veins and the inferior vena cava. The study was carried out on 20 specimens obtained from adult cadavers of both sexes, fixed in 10% formaldehyde solution. The hepatic veins with their junctions on the inferior vena cava were isolated. Then a macroscopic analysis of the openings of the hepatic veins into the inferior vena cava was performed. Part of this material was embedded in paraffin, submitted to serial sectioning and stained with Azan's trichrome and resorcin-fuchsin. Three hepatic veins were observed in all cases: right, left and the middle. In 20% of the cases the middle hepatic vein opens directly into the inferior vena cava. The hepatic vein openings are supported by two pillars inferiorly united through a semilunar fold. The hepatic vein wall is greatly thickened at the level of its junction with the inferior vena cava, showing a large amount of muscular and collagenous fibers. These bundles constitute a sphincter-like formation which may play a physiological role in the control of the hepatic circulation.