Common Channel Formation and Associated Pancreaticobiliary Disease: Prospective Study by ERCP

Abstract

Background/Aims: Common channel formation has been examined in the resected or postmortem specimens, and the incidence ranged from 55 to 91%. Pancreaticobiliary maljunction with a long common channel causes many pancreatic or biliary diseases due to the two-way regurgitation. However, there are few studies on the length of the common channel and associated diseases. Aim of this study is to examine the incidence of the common channel formation that could be diagnosed by ERCP and assess whether the anatomy of the pancreaticobiliary ductal drainage into the duodenum has any relationship with pancreaticobiliary diseases. Methods: We examined prospectively the formation of the common channel by ERCP in almost serial 208 cases from 2001 to 2003. We diagnosed as separate opening, when there are 2 separate orifices at the papilla endoscopically (complete separation), or the common channel was not detected by injection of contrast material with the catheter tip only just within the single orifice (incomplete separation). The length of the common channel was measured radiologically. Cases forming the common channel were divided into 3 groups as follows: pancreaticobiliary maljunction with a long common channel, high confluence of pancreaticobiliary ducts with the common channel 6 mm or longer in which the communication between the pancreatic and bile ducts destroyed with contraction of the sphincter, common channel between 2 and 5 mm. Results: Formation of the common channel was observed in 43 cases (20.7%); 7 pancreaticobiliary maljunction, 8 high confluence of pancreaticobiliary ducts and others. Complete separation was detected in 29 cases. Age on ERCP and sex ratio did not differ in the formation or length of the common channel. Gall stones were associated in 32.6% of cases with the common channel and 29.7% of cases without. Pancreatic carcinoma was 11.6% of cases with the common channel and 17.6% of cases without. The incidences of associated acute pancreatitis and gallbladder carcinoma in cases with the common channel were 18.6% and 16.2%, which were significantly higher than 4.2% and 0.6% of cases without (p<0.01). Conclusions: Formation of the obvious common channel was observed only 20.6% under ERCP study. A close relationship is suggested between the formation of the common channel and development of acute pancreatitis and gallbladder carcinoma.