Surgical aspects of hepatic segmentation based on hepatic venographies.

Hepatic venographies were performed selectively in 42 patients with hepatocarcinoma. The findings were evaluated from anterior and lateral views. Thirty-nine right hepatic v. could be identified and the existence of one branch as the first ramification was found in 36 cases (92.3%). The first branches of the right hepatic v. could be classified into veins (V7) running from segment VII and those (V8) running from segment VIII. A V7 was identified in 26 cases (72.8%) and a V8 was identified in 10 cases (27.8%). The vena hepatica dorsalis (V8) running from segment VIII was recognised in 10 cases. The middle and left hepatic v. were identified in 31 cases and 33 cases respectively. Two main types of middle vein (one with no principal branching and the other with branching) were found in 11 cases (37.9%) and 12 cases (41.4%) respectively. The first branch of the middle hepatic v. (V8) running from segment VIII was identified in 10 cases (32.3%). These results indicate that anatomical consideration of the hepatic v. in each patient is necessary when performing hepatic resection.