Biliary Atresia

Biliary atresia is a pathologic entity in which there is obliteration of some portion of the extrahepatic bile ducts. In the past, occlusion of the proximal ducts (at the liver hilus) was referred to as "noncorrectable" (Fig 1). If only the distal duct is occluded (and the proximal duct is patent), the lesion was referred to as "correctable." The distinction is academic because current treatment and prognosis are identical. The disease is panductular, ie, both extrahepatic and intrahepatic ducts are involved. Early in the disease, however, occlusion is complete only in the extrahepatic system. Without intervention, intrahepatic biliary obstruction and, subsequently, cirrhosis supervene. In the past, except for a few cases of the correctable variant, surgical procedures were unsuccessful until Morio Kasai performed a hepatic portoenterostomy, which was first reported in English in 1968. Bile flow was effectively reestablished in both correctable and noncorrectable forms of biliary atresia. The operation was only successful when done before the patient was 4 months of age. Subsequent confirmation of Kasai's results were reported throughout the world. ETIOLOGY/PATHOLOGY Biliary atresia was originally thought to be a congenital malformation. Careful histopathologic examination of excised surgical specimens indicate that this is not the case; instead, the disease is a dynamic, progressive panductular sclerotic process that may continue in the intrahepatic ducts even after surgical relief of biliary obstruction.