Biliary atresia is obstruction of the biliary tree due to progressive sclerosis of the extrahepatic bile duct. Diagnosis is by blood tests, ultrasonography, liver biopsy, and hepatobiliary scan. Treatment is surgical.
(See also Overview of Congenital Gastrointestinal Anomalies.)
The incidence of biliary atresia in the US is 1 in 10,000 to 15,0000 live births (1).
In most cases, biliary atresia manifests several weeks after birth, probably after inflammation and scarring of the extrahepatic (and sometimes intrahepatic) bile ducts. It is rarely present in premature infants or in neonates at birth. The cause of the inflammatory response is unknown, but several infectious organisms have been implicated, including reovirus type 3 and cytomegalovirus. In addition, there may be a genetic component with defects in one of several genes (CFC1, FOXA2).
Cirrhosis, with progressive, irreversible scarring of the liver, can be present by 2 months of age if the defect is not treated.
About 15 to 25% of infants have other congenital defects, including polysplenia/asplenia, intestinal atresia, situs inversus, and cardiac anomalies or renal anomalies.