Ampulla of Vater. Anatomic, embryologic, and surgical aspects

The region of the ampulla of Vater constitutes a complex anatomic and functional entity, the biliopancreaticoduodenal confluence, of which the essentials of this rapid review are the: Variation in site of implantation of the greater duodenal papilla, whereas the relations between the common bile duct and the main pancreatic duct are relatively constant Presence at this site of a weak point in the duodenal wall, commonly the site of mucosal diverticula Interdependence of the parietal duodenal mucosa and the sphincteric system of Oddi Existence of an extramural zone of this sphincter, which should be the only one involved in sphincterotomy Danger of wide excisions of the papilla, which, apart from the risk for hemorrhage, cause a breach of the digestive barrier The ampulla of Vater corresponds to the dilated junction of the common bile duct and main pancreatic duct, if present. The ampulla is an extensive anatomic and functional region that includes not only the choledochopancreatic junction but also the sphincter of Oddi, the whole traversing the duodenal wall to open at the greater duodenal papilla. The chief anatomic features of this biliopancreaticoduodenal junction have been reviewed, forming the basis of techniques of surgical or endoscopic sphincterotomies and localized excisions of vaterian tumors.

Human fetal development of the hepato-pancreatic duct junction--a possible explanation of congenital dilatation of the biliary tract

Review of 20 cases of congenital dilatation of the common bile duct in childhood showed an association with anomalous choledocho-pancreatic junction in 8. Study of human fetuses showed that the choledocho-pancreatic junction was outside the wall of the duodenum before 8 wk gestation and moved inward and towards the duodenal lumen as age advanced. Arrest of this migration can explain the formation of the anomalous junction. Normal formation of the sphincter of Oddi may also be affected by this process, and lead to functional obstruction and dilatation of the common bile duct.