Management of congenital bile duct cysts.

Bile duct cysts (BDC) are rare congenital anomalies of the biliary tree that are characterized by cystic dilatation of the extrahepatic and/or intrahepatic bile ducts. Presence of an anomalous bilio-pancreatic junction allowing pancreatic juice to reflux into the biliary tree is the most widely aetiopathogenic concept currently accepted. BDC are associated with biliary stasis and lithiasis, and the whole biliary epithelium is considered at risk of malignant transformation. Magnetic resonance cholangio-pancreatography is currently the most accurate preoperative imaging study to assess cyst anatomy and classify the disease according to the standard Todani classification. Complete cyst excision with cholecystectomy followed by biliary reconstruction using a Roux-en-Y hepatico-jejunostomy is the treatment of choice for the extrahepatic component of the disease (type I and IV BDC), but cystic involvement up to the roof of the main biliary convergence represents a real surgical challenge to perform complete resection. The optimal treatment of intrahepatic bile duct dilatations remains controversial, especially for type IV-A BDC. In type V BDC (Caroli's disease), extent of the liver resection is tailored to intrahepatic disease extent and takes into consideration the presence and severity of underlying chronic liver (congenital hepatic fibrosis) and kidney disease. Late postoperative cholangitis secondary to intrahepatic strictures and lithiasis, as well as the risk of metachronous cholangiocarcinoma that can occur throughout the whole biliary tree even after complete cyst excision, represent serious complications justifying careful long-term follow-up.