Choledochal cyst.

Choledochal cyst (CC) or congenital biliary dilatation, has a skewed distribution with hereditary features that is far more common in East Asian females. CC is usually associated with pancreaticobiliary malunion (PBMU) forming a common channel. CC requires early definitive diagnosis, since there is a risk for malignancy occurring in the CC and/or intrahepatic bile ducts (IHBD). Complete CC excision and Roux-en-Y hepaticoenterostomy is required and can be performed by open or minimally invasive surgery with hepatojejunostomy the recommended procedure of choice. Principles of open surgical intervention form the basis of minimally invasive management with laparoscopy and robotic assistance. Current surgical management is associated with fewer early and late complications, such as hepaticoenterostomy anastomotic leakage, cholangitis, anastomosis stricture, and cholangiocarcinoma. Specific features of CC management at Juntendo include: intraoperative endoscopy of the common channel and IHBD for inspecting and clearing debris to significantly reduce post-operative pancreatitis or stone formation; near infra-red fluorescence with indocyanine green for visualizing tissue planes especially during minimally invasive surgery for CC; and a classification system for CC based on PBMU that overcomes inconsistencies between existing classification systems and clinical presentation.