Normal anatomy

The biliary ducts

The intrahepatic biliary ducts from the right and left lobes unite at the hilum to form the common hepatic duct. This lies to the right of the hepatic artery and ventral to the portal vein. The hepatic duct runs caudally and medially towards the duodenum. The cystic duct, 3-4 cm in length, joins the hepatic duct to form the common bile duct. This is 6-8 cm long and approximately 6 mm wide. The common bile duct and the portal vein both lie in the hepatoduodenal ligament. The most distal part of the common bile duct runs in the head of the pancreas, surrounded by pancreatic tissue, before it joins the pancreatic duct from the right to run into the duodenum in the major papilla of Vater.

The gallbladder

The gallbladder lies on the inferior surface of the liver, and its own inferior surface is covered by peritoneum. The organ is 7-10 cm long and 3 cm in diameter with a volume of 30-50 ml. The thickness of its wall is 2-3 mm. The fundus of the gallbladder points ventrally and the neck runs dorsally into the cystic duct.

Gallbladder anomalies occur, the commonest being a septum, usually situated in the fundus which partially divides the organ (the "Phrygian cap"). Very infrequently agenesis occurs resulting in absence of the gallbladder. Duplication or even triplication of the gallbladder may occur but these anomalies are very rare.

David J. Allison and Carl-Gustaf Standertskjold-Nordenstam