Biliary Atresia - C.L.A.S.S. Biliary Atresia Biliary atresia is the congenital absence or closure of the ducts that drain bile from the liver. A network of tubular structures and tiny ducts form the biliary system to drain bile from the liver to the small intestine where it aids in the digestive process. Biliary atresia is the closure or disappearance of the biliary system.
Biliary atresia is a progressive inflammatory process that begins very soon after birth.
In the most common form, called extrahepatic biliary atresia, the delicate ducts outside the liver are affected first. White blood cells invade the ducts, which become damaged and may whither or completely disappear. Bile is trapped inside the liver and rapidly causes damage and scarring to the liver cells. Further scarring of the liver tissue may result in cirrhosis. On average, there is one case of biliary atresia out of every 15,000 live births.