Topography and distribution of ostia venae hepatica in the retrohepatic inferior vena cava.

Abstract

Background : Openings of hepatic veins into the retrohepatic surface of the inferior vena cava (ostia venae hepatica) play a part in controlling hepatic circulation by acting as collateral channels in obstruction. Their topography and distribution must be taken into account during catheterization and liver transplantation. This anatomy is however little known among Kenyans.

Objectives: To study the position, number and distribution of ostia venae hepatica in a selected Kenyan population

Materials and methods: Eighty fresh postmortem liver specimens were obtained from the Chiromo Mortuary. The hepatic IVC was isolated from the lower border of caudate lobe to the diaphragmatic opening, with the liver in position. The vein was opened posteriorly by a vertical incision along its whole length and the lateral flaps reflected laterally. The topography of the ostia was studied using the Sahni model. The number and patterns of the ostia were also studied. The patterns of openings of the left, right and middle hepatic veins were studied as well as the distances between them.

Results : A total of 584 ostia were identified, an average of 7.3 per liver. The ostia were distributed on the lateral portions of the vein, with an avascular plane at the centre. Major veins terminated in the upper third of the hepatic inferior vena cava, with little extraparenchymal course. The mean distance between the right hepatic vein and middle hepaticvein was 1.7cm

Conclusion : The numerous ostia venae hepatica identified in these subjects offer collateral flow channels during hepatic venous obstructionin Budd-Chiari syndrome. The topography and patterns of distribution of the openings suggest the advantage of an avascular virtual plane, which is asafe dissecting path for hepatovascular surgeons.