The anatomical relationship between the retropancreatic part of the bile duct and the main pancreatic duct.

The main pancreatic duct lies posteriorly within the head of the pancreas and adjacent to the retropancreatic part of the common bile duct. In 17 out of 25 (68%) autopsy specimens which were studied, the two ducts ran within 5 mm of each other for a mean distance of 3.9 cm. The pancreatitis which sometimes develops as a complication of instrumentation of the bile duct could be a result of damage to the main pancreatic duct.