Biliary Atresia

Atresia = “absence or abnormal narrowing of an opening or passage in the body”

Effects 1 in 14,000 live births

Progressive disease in which there is destruction or absence of the extrahepatic biliary tree and intrahepatic bile ducts. This can cause cirrhosis.

Cirrhosis is a chronic degenerative disease in which normal liver cells are damaged and are then replaced by scar tissue.

Babies have normal birth weight but then fail to thrive and are jaundiced from second day. Stools are pale and urine dark (stool and urine colour may fluctuate)

This is predominantly CONJUGATED HYPERBILIRUBINAEMIA.

Causes of hyperbilirubinaemia in the newborn:

  • Bile duct obstruction
    • Biliary Atresia
    • Choledochal cyst
  • neonatal hepatitis
    • Congenital infection
    • Inborn errors: alpha-1 antitrypsin deficinecy
    • Galactosaemia

 

They develop portal hypertension. The portal vein carries blood from stomach, intestines, spleen and gallbladder to the liver. In cirrhosis the normal bloodflow is impeded by scar tissue and therefore increased pressure in the portal system. This can cause varacies in the distal oesophagus that can then bleed.

Image result for portal vein

Biliary atresia leads to chronic liver failure and death unless there is rapid surgical intervention.

Diagram of the Kasai procedure with liver, stomach, and small intestine labeled.

In the Kasai procedure (Hepatoenterostomy), the damaged bile ducts are removed, and a loop of small intestine is bought up to replace them. If surgery is performed before 60 days, 80% of children will achieve bile drainage. the success rate diminishes with increasing age.

Post op complications include cholangitis and fat malabsorption.

Even when bile drainage is successful there may be progressive cirrhosis and portal hypertension.

As a result, these patients usually require a liver transplant by adulthood.

https://www.niddk.nih.gov/health-information/liver-disease/biliary-atresia

Illustrated Textbook of Paediatrics Tom Lissauer ad Graham Clayden, 3rd edition, pages 338-339