Adenoma and stone formation of the biliary tract in puppies that had choledochopancreatic anastomosis

A canine model of anomalous choledochopancreatic ductal junction (APCDJ) was produced by choledochopancreatic end to side ductal anastomosis performed in 77 mongrel puppies weighing between 1.5 and 5 kg. Histopathological studies of the biliary tract showed that as the post-operative period became lengthened metaplasia and hyperplasia increased. In nine dogs that lived for over 5 years after the operation, papillomatous adenoma occurred in four (44%), and biliary stones in seven (78%). The histological changes seen in the biliary epithelium of our experimental canine model suggest that bile duct carcinoma may be due to the persistent return of pancreatic juice into the bile duct in patients with APCDJ.