Diverse morphology of biliary atresia in an animal model

Background/Aims: Extrahepatic biliary atresia can be simulated in Balb/c-mice which have been infected with rotavirus. Irreversible occlusion of the common bile duct is the result of an inflammatory process of the whole biliary tract. The observations in this animal model are similar to extrahepatic biliary atresia in newborn children. The present study describes the wide range of morphological findings in mice and compares the results with several classifications of extrahepatic biliary atresia in children. Methods: Newborn Balb/c-mice were infected intraperitoneally with rhesus rotavirus; the pathological morphology of the extrahepatic bile ducts in 73 mice is described and illustrated by scanning electron microscopy. Results: The extension and localisation of atresia varied from short to interrupted or long-segment atresia, with or without prestenotic dilatation. The gallbladder was small and atretic, or appeared hydropic due to atresia of the common bile duct. The wide range of pathomorphological findings is the final stage of an inflammatory process. The morphological changes of the extrahepatic bile ducts do not fit any pattern, and no classification is evident. Conclusions: Most types of extrahepatic biliary atresia in children can be mimicked in this animal model. Comparing these observations with different classifications of extrahepatic biliary atresia in children, it must be asked if any classification of the disease is justified, having regard only to pathomorphological findings in the extrahepatic biliary tract.