Biliary atresia

• What are some risk factors for biliary atresia?


  Genetic

  Immune-mediated

  Environment
• What are some genetic risk factors for biliary atresia?

  Gene mutations in:

  • ADD3
  • GPC1
  • ARF6
• What are some immune mediated causes of biliary atresia?


  Presence of autoantibodies and T cells in affected liver tissue

  Perinatal viral infection
• How does a perinatal viral infection lead to an immune-mediated cause for biliary atresia?

  Triggers an immune response against antigens shared by the bile duct and virus = chronic inflammation and fibrosis
• What are some environmental factors that lead to biliary atresia?


  Exposure of polychlorinated biphenyls and dioxins during pregnancy
• How many different types of biliary atresia are there?


  3
• What is type 1 biliary atresia?


  Atresia confined to common bile duct

  20% of all cases
• What is type 2 biliary atresia?


  Hepatic ducts are affected
• What is type 2a biliary atresia?


  Only hepatic duct is affected
• What is type 2b biliary atresia?


  Both hepatic and common bile ducts are affected
• What is type 3 biliary atresia?


  Obliteration of extrahepatic bile ducts -> discontinuity between liver hilum and duodenum
• What is type 3a biliary atresia?


  Patent intrahepatic bile ducts but obliterated porta hepatitis
• What is type 3b biliary atresia?


  Complete obliteration from porta hepatis to duodenum
• What are some signs and symptoms of biliary atresia?


  Jaundice

  Acholic stools

  Dark urine

  Failure to thrive

  Vitamin deficiencies

  Cirrhosis

  Portal hypertension

  Hepatomegaly

  Splenomegaly
• What would bloods show in biliary atresia?


  High bilirubin

  Raised AST, ALT, GGT

  Prolonged prothrombin time
• What scans and imaging are done for biliary atresia?


  Ultrasound

  HIDA
• WHat does HIDA stand for?


  Hepatobiliary iminodiac acid
• When is a HIDA scan done?


  If ultrasound results are inconclusive
• What are some invasive investigations for biliary atresia?


  Liver biopsy

  Intraoperative cholangiogram
• What are some ddx of biliary atresia?


  Neonatal hepatitis

  Choledochal cysts

  Alagille syndrome
• What is the goal for the management of biliary atresia?


  Restore bile flow from liver into intestine
• What is some conservative management of biliary atresia?


  Administration of vitamins

  Nutritional support

  Monitoring LFTs, coag profile, growth parameters

  Ultrasounds
• What medication can be given for biliary atresia?


  Choleretic agents to improve bile flow
• What are some surgical managements of biliary atresia?


  Kasai portoenterostomy

  Liver transplant
• What management is seen as 'definitive therapy' for biliary atresia?


  Liver transplant
• What is a Kasai portoenterostomy?


  Removal of damaged bile ducts outside of liver -> create new path for bile to flow