Biliary duct dilatation is a relatively common congenital disorder of the biliary system, with congenital common bile duct cysts (also known as bile duct dilatation) being the most common clinically. The typical clinical presentation is jaundice, abdominal pain and a right upper abdominal mass. The majority of patients are children and a minority are adults. Causes include congenital abnormal biliopancreatic duct coaptation, abnormal bile duct development, and distal obstruction of the common bile duct. Type I: cystic dilatation of the common bile duct, the most common type, accounting for more than 90% of patients, 80% of whom are women. Multiple cystic dilatation (Caroli disease) Since patients with bile duct dilatation are at higher risk of secondary biliary obstruction, infection, and stones, and have the potential for malignancy, the current concept of treatment is early surgical removal of the diseased bile duct and reconstruction of the biliary drainage system. Patients with types I, II, and IV-B can be treated by resection of the bile duct lesion area combined with bile-intestinal anastomosis, while patients with types III and IV-A
Type III and IV-A patients need to choose the surgical method according to the extent of lesion involvement, and type V patients need to be treated with liver transplantation.