The portal triad structures of the liver, hepatic artery, portal veins and biliary tree share a common distribution pattern to and from the centers of the hepatic segments. The venous drainage of the liver converges from the segments to three main channels, right, left and middle hepatic veins, lying between major hepatic segmental divisions. Hepatic resection must preserve the venous drainage of the remaining segments.
The anterior and cephalad surfaces of the liver lie up against the parietal peritoneum. The diagonal plane of the underside of the liver lies against the stomach, duodenum, right kidney and hepatic flexure of the colon. A portion of the inferior vena cava is embedded in liver substance.
The Couinaud segmental classification of the liver of 1957 has been generally accepted for the description of hepatic surgery. The line (Cantile’s) between the gallbladder bed and the inferior vena cava is the anatomic division between right and left lobes.