An applied anatomical study of the ostia venae hepaticae and the retrohepatic segment of the inferior vena cava.

In sixty normal adult livers the retrohepatic segment of the inferior vena cava was found mostly to assume a curve to the left (75.00%). This segment has a length of 7.1 cm and is totally encircled by liver substance in 6.67% of cases. Altogether 492 ostia venae hepaticae were studied, averaging 8.2 per liver and classified as large, medium and small. The large ostia are divided into superior (SLO) and inferior (ILO) openings. The SLO are found opening into the upper end of the hepatic segment of the inferior vena cava, frequently with part of the venous walls exposed outside the liver. The ILO and medium ostia are present in 95% of the livers, appearing mainly on the lower quarter of the right half of the wall of the retrohepatic segment of the inferior vena cava as well as on the left anterior wall of that segment. The ILO may serve as the exit for several hepatic veins and they may be multiple. Their significance in respect of liver surgery is discussed.