[Atresia of the extrahepatic bile ducts. Etiological hypothesis founded on a histological study of 130 fibrous remnants].

The hypothesis which might explain the congenital absence of extrahepatic bile ducts are reviewed from the study of samples obtained at surgery in 240 children with extrahepatic biliary atresia, and more especially from the pathologic study of 130 fibrous remnants taken as the first step of hepato-porto-enterostomy. This study allows the following pathophysiologic hypothesis: Epithelial damage occurring before birth and always at the same site in the biliary bud that has undergone normal migration and differentiation could be responsible for an atresia. The lesion could be due to abnormal vascularisation with the consequences similar to those observed in other hollow viscera. Below the lesion, bile retention would cause epithelial destruction and an inflammatory infiltrate as in auto-immune reactions. The portal fibrosis which progresses despite restoration of bile flow would be the result of stimulation of growth of the portal mesenchymal axis, which embryologically is only an extension of the fibrous remnant. This hypothesis could explain why it has never been possible to reproduce the condition exactly in animals because all experiments have been performed after birth.