Biliary atresia and congenital disorders of the extrahepatic bile ducts

Table 2 Classification of the choledochal cysts

Type	Description
Type I	Cystic dilatation of the common bile duct. Also cysts there may be at extrahepatic right and left hepatic ducts and at common hepatic ducts. Intrahepatic bile ducts are unaffected
Type Ia	Large saccular cystic dilatation of the common bile duct, with dilatation of the common hepatic duct and the right and left hepatic duct
Type Ib	Focal and segmental dilation of the common bile duct
Type Ic	Diffuse fusiform dilation of the common bile duct
Type II	Common bile duct diverticulum
Type III	Cysts in the intraduodenal part of the common bile duct – known as choledochocele
Type IV	Multiple extrahepatic alone, or multiple extrahepatic and intrahepatic cysts together
Type IVa	Extrahepatic and intrahepatic cysts
Type IVb	Multiple extrahepatic cysts (common hepatic duct, common bile duct and intraduodenal common bile duct)
Type V	One or more cystic dilatation of the intrahepatic bile duct. Multiple intrahepatic bile duct cysts are defined as Caroli disease