乳幼児黄疸肝における走査型電子顕微鏡学的研究

抄録

Scanning electron microscope (SEM) studies of the liver in animal and adult humans have been reported by many authors recently. However, as far as cholestatic diseases of infancy are concerned, no reports have appeared in literature. The present study extends SEM observations to the luminal surface of the hepatic biliary system in order to clarify among the various cholestatic diseases of infancy. Liver biopsy specimens from 50 patients [26 with biliary atresia (BA), 4 with intrahepatic cholestasis (IHC), 3 with paucity of intrahepatic bile ducts, 12 with choledochal cyst and 5 normal controls (1mo. 7mo. 1y. 2y. 54y.)] were studied. 1) In the cases studied with choledochal cysts, hepatic cells were already transformed into one-cell-thick plate in all cases more than 2 years old, and bile canaliculi (BC) and interlobular bile duct (BD) appeared to be normal. In the cases with dilated intrahepatic bile ducts, BC and BD appeared to be almost normal. When jaundice presented as acomplication just before or at the time of operation, however, the evidence of secondary damage was observed at the level of BC and BD. It is therefore suggested that pathological changes a ssociated with choledochal cysts in located at the large extra- and intra-hepatic bile ducts. 2) In IHC, BC dilatation and disappearance of the BC microvilli was demonstrated.In contrast, BD showed and almost normal appearance. It is therefore suggested that regurgitation of bile in IHC occurs at the level of the BC or canaliculo-ductular junciton (C-DJ). 3) With paucity of intrahepatic bile ducts, pathological change of the BC appeared to be similar to that of IHC. BD was partly abnormal. Discontinuity of BD was demonstrated in some portions of the liver in a few cacses. 4) In BA the majority of cases at the time of the initial operation had two-cell-thick plates of liver cells, the same as that of normal controls less than one year old, BC and BD were moderately injured. At the second biopsy of the liver 2 or 3 months after the successful initial operation, marked improvement of BC was observed, and BD had recoverd to some degree. Improvement of BC suggests that obstruction of bile does not occur at the level of neither the BC, C-DJ nor bile ductules. At the third biopsy of the liver 2 or 3 years after the operation without cholestasis, BC were almost normal and hepatic cells had transformed into one-cell-thick plates, but occasionally in some portions of the liver, two-cell-chick plates remained. In contrast, impairment of the microvilli and cilia of the BD was still evident in all cases, especially in those cases complicated with postoperative cholangitis. Therefore the biliary system in BA does not show complete resolution 2 or 3 years afters operation.