The presence of a common channel and associated pancreaticobiliary diseases: a prospective ERCP study.

BACKGROUND: There are few endoscopic retrograde cholangiographic studies dealing with the relationship between the presence of a common channel and associated pancreaticobiliary diseases. AIMS: To endoscopically determine the incidence of common channels and assess whether the anatomy of the pancreaticobiliary ductal drainage into the duodenum has any bearing on pancreaticobiliary diseases. PATIENTS AND METHODS: We prospectively examined a common channel formation in 354 endoscopic retrograde cholangiographic cases. Cases with a common channel were divided into three groups: pancreaticobiliary maljunction, high confluence of pancreaticobiliary ducts with a common channel > or =6 mm in which the communication was occluded with the sphincter contraction, and common channel < or =5 mm in length. RESULTS: A common channel was observed in 131 cases (37.0%) including 11 with pancreaticobiliary maljunction and 13 with high confluence of pancreaticobiliary ducts. In cases with a common channel, the incidences of associated gallbladder carcinoma and acute pancreatitis were both 11.5%, which were significantly higher than 1.8% and 4.9% seen in cases without a common channel. In pancreaticobiliary maljunction cases, incidence of associated gallbladder carcinoma was 72.7%. CONCLUSION: The presence of an obvious common channel was observed in 37.0%. A close relationship is suggested between the presence of a common channel and development of gallbladder carcinoma and acute pancreatitis.