An Experimental Animal Model of Anomalous Pancreaticobiliary Duct Union

ABSTRACT

It is generally believed that the anomalous pancreaticobiliary duct union (APBDU) might be involved in the formation of choledochal cyst and malignancies of hepatopancreaticobiliary system. The purpose of this study is to make an animal model of APBDU similar to that of human. One to two-month-old Mongrel dogs (n=12) were divided into two groups; the control group (n=2) in which sham operation was performed, and the experimental group (n=10) in which the end of distal common bile duct (CBD) was anastomosed to the side of dorsal pancreatic duct to produce APBDU. Serum was obtained for chemical analysis at the 10th postoperative day. The dogs were sacrificed at the 5th week (n=3), the 6th week (n=3), the 7th week (n=2), the 8th week (n=2) and the 6th month (n=2) after the operative intervention. At the day when the experimental animals were sacrificed, operative cholangiogram was taken, and bile juice was obtained for chemical analysis and bacterial culture. The en-bloc specimens of hepatopancreaticobiliary system were obtained for microscopic examination. Serum and bile juice amylase levels were elevated in the experimental group (n=10), but not in the control group (n=2). On operative cholangiogram, there was no evidence of bile duct dilatation in control group (n=2). On the other hand, bile duct in the experimental group was markedly dilated without any evidence of stenosis in all (n=10). Histologic examination of the hepatopancreaticobiliary system in the experimental group resembled the findings of choledochal cyst in human. The APBDU of this animal model can produce bile duct dilatation by pancreaticobiliary reflux. We think that this animal model can be potentially promising for the research about the APBDU associated hepatopancreaticobiliary diseases.