ABSTRACT
The lower portion of the CBD lies in contact with the head of the pancreas for between 2 and 7 cm and 40% of the time it lies in a groove between the surface of the pancreas and the duodenum. In the remainder of cases, it lies within the parenchyma of the pancreas ( 7 ). During embryological development, the lower duct of Wirsung arises in the ventral pancreatic bud adjacent to the early hepatic duct. Therefore, the association of the duct of Wirsung with the CBD is a consistent feature of the ductal anatomy of the pancreas ( 1 ). The duct of Wirsung and the CBD unite 6 to 8 mm within the papilla and form a common channel, which is slightly dilated and referred to as the ampulla of Vater. In just over 10% of cases, the two ducts do not form a short common channel and instead enter the duodenum independently on the papilla ( 5 ).
