title: Kasai portoenterostomy--new insights from hepatic morphology.
abstract: OBJECTIVE
  The aim of this paper was to investigate the mechanism of long-term biliary drainage after Kasai portoenterostomy by clinicopathologic study of hepatic morphology in explanted livers.
  
  
  METHODS
  Explanted livers from 13 consecutive children undergoing transplantation for biliary atresia were examined in detail using a standardized protocol. Group 1 (n = 6) had no Kasai procedure before transplantation at a median age of 8 m. Group 2 (n = 4) were transplanted at a median age of 10 m after a failed Kasai portoenterostomy. Group 3 (n = 3) had a successful Kasai but required transplantation for complications of chronic liver disease at 12-14 years. Pathology findings were correlated with hepatic morphology determined by pretransplant magnetic resonance imaging.
  
  
  RESULTS
  Large perihilar regenerative nodules (8-14 cm diameter) were observed in 2 patients after successful Kasai portoenterostomy, less well-defined perihilar nodules in group 2 patients, and no regenerative nodules in group 1. Microscopically, group 1 had diffuse biliary cirrhosis with evidence of progressive ductopenia during infancy. In group 2, perihilar regenerative nodules showed variable portal fibrosis but no cirrhosis and bile ducts were present with 68%-100% of hepatic arteries; in peripheral cirrhotic areas, bile ducts were absent in patients older than 9 m. The perihilar regenerative nodules in group 3 patients had a noncirrhotic architecture with preserved bile ducts, but the peripheral parenchyma was cirrhotic; one patient had diffuse macronodular cirrhosis. These morphologic findings correlated well with magnetic resonance images, highlighting the preservation of relatively normal perihilar liver architecture after successful Kasai portoenterostomy.
  
  
  CONCLUSIONS
  Unoperated biliary atresia is associated with progressive intrahepatic ductopenia leading to diffuse biliary cirrhosis. Kasai portoenterostomy can result in the growth of large perihilar regenerative nodules, probably as a consequence of surviving intrahepatic ducts in this region. In some patients, long-term success after Kasai portoenterostomy may depend on hyperplasia of the perihilar liver.
authors.affiliation: Department of Histopathology and Children's Liver Unit, St James's University Hospital, Leeds, LS9 7TF, UK.
authors.forename: Ali
authors.initials: A
authors.lastname: Hussein
authors.forename: Judy
authors.initials: J
authors.lastname: Wyatt
authors.forename: Ashley
authors.initials: A
authors.lastname: Guthrie
authors.forename: Mark D
authors.initials: MD
authors.lastname: Stringer
mesh_terms: D000293:Adolescent; D001653:Bile Ducts, Intrahepatic / Q000473:pathology*; D001656:Biliary Atresia / Q000150:complications* / Q000601:surgery*; D006498:Hepatectomy; D006499:Hepatic Artery / Q000473:pathology; D006801:Humans; D007223:Infant; D008105:Liver Cirrhosis, Biliary / Q000209:etiology / Q000473:pathology* / Q000601:surgery; D008115:Liver Regeneration; D016031:Liver Transplantation; D008279:Magnetic Resonance Imaging; D011171:Portoenterostomy, Hepatic; D011183:Postoperative Complications