Action of pancreatic juice on the bile duct: pathogenesis of congenital choledochal cyst.

Babitt was the first to suggest that the anomalous arrangement of the pancreatico-biliary ducts might be involved in the etiology of congenital choledochal cyst. Since then, many authors have reported this condition frequently associated with congenital choledochal cyst. The reflux of pancreatic juice into the common bile duct due to this anomaly has been thought to be responsible for the formation of choledochal cyst. Our previous study using the animal model with anomalous arrangement of pancreaticobiliary ducts, has proven that pancreatic juice in the common bile duct caused cystic dilatation of the common bile duct. However, the mode of action of pancreatic juice on the biliary duct has remained unclear. The present study using peroxidase as a tracer for permeability of the biliary duct showed early damage of the intercellular junction of biliary epithelium exposed by pancreatic juice, followed by affection of submucosal tissue.