Abstract
The main papilla of the duodenum was examined in 72 autopsied cases showing no remarkable changes in the biliary tract and pancreas. Attention was focused on the anato-my of the orifice and longitudinal fold. The length of an oral protrusion was defined as a distance between the upper end of the longitudinal fold and the orifice. The results were as follows: 1) The length of the inraduodenal portion of the common bile duct (IBD) was 12.2 mm, and it showed a positive correlation with the length, height and width of the oral pro-trusion, and a negative correlation with the angle between the common bile duct and the duodenum. 2) The resectable length without perforation of the duodenal mucosa was 10.4 mm, which was 2.6 mm longer than the length of the oral protrusion. 3) The narrow distal segment of the common bile duct was 13.7 mm in length, and 1.5 mm of its length was extraduodenal. 4) The length of an extraduodenal portion of the sphincter of the choledochus was 5.2 mm. 5) In 65% of the cases, the common bile duct and pancreatic duct opened together at the main papilla, and in the other cases they opened separately. 6) The main papilla was supplied by two large arteries, the artery (Artery 1) supply-ing the longitudinal fold, being larger. Artery 1 entered from the border of the proper mus-cle of the duodenum and common bile duct. 7) The resectable length without bleeding was 1.1 mm shorter than the IBD.
