<Todani classification>
Type I: Most common variety (77-87%) involving saccular or fusiform dilatation of a portion or entire common bile duct (CBD) with normal intrahepatic duct.
Type II: Isolated diverticulum protruding from the CBD(1.2-3%).
Type III or Choledochocele: Arise from dilatation of duodenal portion of CBD or where pancreatic duct meets(1.4-6%).
Type IVa: Characterized by multiple dilatations of the intrahepatic and extrahepatic biliary tree(19%).
Type IVb: Multiple dilatations involving only the extrahepatic bile ducts(rare).
Type V or Caroli's disease: Cystic dilatation of intra hepatic biliary ducts(rare).
Type I: Most common variety (77-87%) involving saccular or fusiform dilatation of a portion or entire common bile duct (CBD) with normal intrahepatic duct.
Type II: Isolated diverticulum protruding from the CBD(1.2-3%).
Type III or Choledochocele: Arise from dilatation of duodenal portion of CBD or where pancreatic duct meets(1.4-6%).
Type IVa: Characterized by multiple dilatations of the intrahepatic and extrahepatic biliary tree(19%).
Type IVb: Multiple dilatations involving only the extrahepatic bile ducts(rare).
Type V or Caroli's disease: Cystic dilatation of intra hepatic biliary ducts(rare).