Expansion
Union of the bile duct and main pancreatic duct opening into the second part of the duodenum
Expansion
- The common bile duct and the main pancreatic duct (of Wirsung) unite to form the hepatopancreatic ampulla
- It opens at the major duodenal papilla, on the posteromedial wall of the second part of the duodenum, about 8 to 10 cm beyond the pylorus
- Flow is controlled by the sphincter of Oddi, with separate components around each duct and around the ampulla itself
The accessory pancreatic duct (of Santorini) usually opens separately at the minor papilla, about 2 cm proximally.
This shared channel explains gallstone pancreatitis: a stone impacted at the ampulla obstructs the pancreatic duct as well as the bile duct, producing both obstructive jaundice and pancreatitis. It also marks the foregut-midgut boundary, and thus the transition in blood supply from coeliac to superior mesenteric territory.