Anatomy of the retrohepatic segment of the inferior vena cava and the ostia venae hepaticae with its clinical significance.

PURPOSE: The present study was undertaken to provide morphological data regarding the retrohepatic segment of the inferior vena cava (RHIVC) and ostia venae hepaticae with an emphasis on the clinical significance of the observations made.
METHODS: This was an observational study conducted on 160 apparently healthy, randomly selected, cadaveric adult human livers fixed in 10% formalin. The distribution of the hepatic venous openings was studied by dividing the interior of the RHIVC into 16 quadrants. These openings were classified as large, medium, small and very small openings based on their diameter and were also classified as single/double/triple/quadruple according to the number of veins opening into them.
RESULTS: The median length of RHIVC was 7.3 cm (6.2-8.4) and was directed obliquely with respect to the vertical axis of the liver in 92.5% of cases. A total of 1,376 ostia venae hepaticae were observed, and the median number of openings per liver was 7 (5-9). The right hepatic vein had a single opening in 156 (97.5%) and the left and middle hepatic veins had a common opening in 144 (90%) cases. A longitudinal area on the anterior wall of the RHIVC, to the right side of the midline, was relatively avascular with 10.1% of the venous openings, of which 70% were single openings of the right dorsal vein having a small diameter (0.1-0.5 cm).
CONCLUSION: During liver hanging maneuver, rightward direction of the dissecting forceps would avoid injury to the caudate vein and allow access to the safe avascular space in the RHIVC. © Springer-Verlag 2011