Abstract
PURPOSE: We investigate the histopathology of the portal vein branches and lymphatic vessels to elucidate the mechanism of atrophy of the left lateral segment (LLS) of the liver in biliary atresia (BA). METHODS: LLS and right anterior segment (RAS) liver biopsy samples obtained during Kasai portoenterostomy (KPE) from ten consecutive patients with BA underwent histopathological investigation of the portal vein and lymphatic vessels using double chromogenic immunostaining for CD31/D2-40 and the hepatitis-like findings (HLF) score. Each parameter and clinical data were compared between prognostic groups. RESULTS: HLF scores in the LLS were always higher than those in the RAS. There was no difference in portal vein and lymphatic vascular morphology, whereas the number of lymphatic vessels was correlated with the fibrotic area of all specimen areas. Left-to-right ratio of the number of lymphatic vessels was correlated with the age at KPE (r = 0.784, p = 0.007) and the pre-KPE CRP value (r = 0.723, p = 0.018). CONCLUSIONS: Lymphangiogenesis on the LLS compared to the RAS was significantly correlated with the degree of fibrosis and the age at KPE. Further investigation is warranted to clarify the causes of LLS atrophy and lymphangiogenesis relevant to immune dysregulation.