Modern surgical techniques depend in part on knowledge of both the "normal" and the anomalous arterial blood supply. For instance, in liver transplantation, during surgery of the gallbladder, gastrectomy, and gastric lymphadenectomy, or when selective arterial chemotherapy is used for treatment of liver cancer, aberrant hepatic arteries can be a significant problem. A series of 138 cadavers with arterial latex injection were dissected and 10 corrosion casts were made to obtain an exact knowledge of the topography of the normal and anomalous arteries of the lesser omentum in humans. The so-called normal anatomy was found in only 9% (15 of 148 individuals), the remaining five-sixths presenting some variations from this, many of direct surgical importance. In these cases one or two aberrant hepatic arteries (37%), an artery in the free border of the hepatoduodenal ligament (19%), a right hepatic artery crossing the portal vein posteriorly (4%), the right hepatic artery entering the triangle of Calot anteriorly (29%) or not (7%), or an accessory left gastric artery branching off the left hepatic artery (2%) were found.