Figure 2.

Normal arterial pattern of extrahepatic biliary tract. Supraduodenal CBD is primarily supplied by 3 o'clock (left) and 9 o'clock (right) marginal arteries contributed from posterior superior pancreaticoduodenal artery (PSPDA) from below and right hepatic (RHA), Left hepatic (LHA) and Cystic arteries from above. These marginal arteries are comparable to Paracholedochal Plexus (of Petren). Marginal arteries give small branches which form the Epicholedochal plexus. Above, the marginal arteries join the hilar plexus which supply the hilar ducts. Communicating Arcade (CA) connects RHA and LHA and is present cranial to the confluence of right and left hepatic ducts. The CA arises from right anterior sectoral artery (RASA) on the right and segment IV artery (IV A) on the left. RPSA – Right posterior sectoral artery.