Risk of bile duct carcinogenesis after excision of extrahepatic bile ductsin pancreaticobiliary maljunction

Background. A reflux of pancreatic juice into the biliary tract caused by p ancreaticobiliary maljunction (PBM) has been considered important in the de velopment of biliary tract carcinogenesis in choledochal cysts. We excised extrahepatic bile ducts in patients with choledochal cysts to terminate the reflux of pancreatic juice. We investigated whether this surgery could sto p the development of the residual bile duct carcinoma. Methods. Fifty-six patients with a diagnosis of PBM with choledochal dilata tion underwent surgical excision of extrahepatic bile ducts. We applied a p erson-year method to compare the relative risks (observed number/expected n umber) of biliary tract carcinoma before and after surgery. Results. In 3 patients, bile duct carcinoma developed in residual dilated s egments 19 yeats 6 months, 8 years 8 months, and 2 years 5 months, respecti vely, after surgery. Although the relative risk in the post-surgery group w as slightly decreased by surgery, it was still high compared with that of t he general population. Conclusions. The incidence of bile duct carcinoma is still high, even after excision of extrahepatic bile ducts in PBM patients with choledochal dilat ation. For these patients, careful long-term follow-up is necessary, especi ally after operations that leave the dilated bile ducts, such as cases of T odani's type IV-A.