Variations in feeding arteries of hepatocellular carcinoma located in the left hepatic lobe

The left hepatic lobe is divided into three subsegments according to anatomical landmarks; however, there are several variations in the vascular territories of the left hepatic arterial branches. Hepatocellular carcinoma (HCC) located near the umbilical fissure or at the left side of the umbilical portion of the left portal vein has frequent crossover blood supply. HCC located in the caudal aspect of the lateral segment has a variety of feeding arteries, and is infrequently supplied by the caudate artery or the medial subsegmental artery (A4), and by the lateral left hepatic arteries. HCC located in the posterior aspect of segment 4 is frequently supplied by the caudate artery or a small A4 branch arising from the caudate artery. In addition, the left inferior phrenic, right and left internal mammary, right and left gastric, cystic, and omental arteries are well known extrahepatic collateral pathways supplying HCC in the left hepatic lobe, especially when the hepatic artery is attenuated by previous transcatheter arterial chemoembolization (TACE). Interventional radiologists should have sufficient knowledge of vascular territories in the left hepatic arterial branches and extrahepatic collaterals to perform effective TACE for HCC located in the left hepatic lobe.