Definition and Clinical Presentation

Biliary atresia (BA) is a neonatal disease characterized by a progressive obliteration of the duct that drains bile from the liver. With loss of adequate drainage of bile, the liver accumulates damage, which, with time, is irreversible.

BA is the most common cause of neonatal direct hyperbilirubinemia, occurring in approximately 1 in 8,000 to 1 in 15,000 live births. Approximately 250 to 400 cases of BA are diagnosed in the U.S. annually.

Biliary Atresia Subtypes

There are two subtypes of BA: fetal and perinatal. Fetal BA is characterized by jaundice from birth, whereas perinatal BA is characterized by a later onset of jaundice. With the persistent jaundice (yellow color of the eyes and skin) due to an obstruction of bile flow, there is also loss of pigment of the infant’s stool, which becomes a pale gray color.

Over time, infants with BA become progressively malnourished and, as a result of progressive liver failure, accumulate fluid within the abdomen.

Etiology and Risk Factors

The exact cause of BA is not well understood but likely has multiple causes:

• Reports of seasonal fluctuations in BA cases suggest an infectious cause
• There is evidence that BA might be associated with exposure to an environmental toxin
• Finally, there is data indicating that mutations in genes involved in the fetal development of the bile ducts may result in BA

Treatment and Prognosis

Treatment with Kasai portoenterostomy, if performed within the first two months of life, results in effective biliary drainage, resolution of liver damage, and long-term survival in approximately one-third of all BA patients.

The remainder of treated patients experience either only transient or no biliary drainage. These patients ultimately require liver transplantation for survival.

The Kasai procedure involves establishing effective drainage of bile using a portion of the infant’s intestine to bypass the obstructed portion of the biliary tree. Ideally, the operation is performed within the first 60 days of life, as progression of the disease upward into the liver makes the likelihood of being able to reach open and functional bile ducts with the intestinal bypass very low. Nonetheless, drainage of bile has been successfully reestablished in older infants, thus, making the Kasai procedure a worthwhile option to consider.


ChiLDREN Liver Research Center