Normal structure, variations, and anomalies of the pancreaticobiliary ducts of Koreans: a nationwide cooperative prospective study.

BACKGROUND: This study evaluated the normal pancreaticobiliary ducts of Koreans and assessed the frequency and pattern of variations and anomalies of these structures. METHODS: A prospective, nationwide multicenter study was performed in which 10 university hospitals in Korea participated from March 1997 to June 1999. A total 10,243 patients undergoing ERCP were enrolled. RESULTS: The mean (SD) maximal and midportion diameters in millimeters of the common hepatic duct were, respectively, 6.1 (1.8) and 5.3 (1.6). The mean maximal and midportion diameters (mm) of the common bile duct were, respectively, 6.4 (1.8) and 5.5 (1.7). The mean maximal and midportion diameters (mm) of the main pancreatic duct in the head, body and tail were, respectively, 3.2 (1.1), 2.7 (1.0), and 2.5 (2.3); and, respectively, 2.2 (0.9), 1.6 (0.7) and 1.4 (0.6). Pancreaticobiliary duct diameters for patients above the age of 40 were greater than those of patients less than 40 years of age (p < 0.05). The frequency of choledochal cyst and anomalous union of the pancreaticobiliary ducts were, respectively, 0.32% and 4.1%. Pancreas divisum and annular pancreas were found, respectively, in 0.49% and 0.05%. CONCLUSIONS: A knowledge of normal pancreaticobiliary ductal structures as well as the frequency and pattern of variations including anomalies is essential for the diagnosis and treatment of pancreaticobiliary disorders.