Biliary Atresia

Definition

Definition of Biliary Atresia
Biliary atresia, also known as "extrahepatic ductopenia" and "progressive obliterative cholangiopathy" is a congenital or acquired disease of the liver and one of the principal forms of chronic rejection of a transplanted liver allograft. As a birth defect in newborn infants, it has an occurrence of 1/10,000 to 1/15,000 cases in live births in the United States. In the congenital form, the common bile duct between the liver and the small intestine is blocked or absent. The acquired type most often occurs in the setting of autoimmune disease, and is one of the principal forms of chronic rejection of a transplanted liver allograft.

Infants and children with biliary atresia have progressive cholestasis with all the usual concomitant features: jaundice, pruritus, malabsorption with growth retardation, fat-soluble vitamin deficiencies, hyperlipidemia, and eventually cirrhosis with portal hypertension. If unrecognized, the condition leads to liver failure -- but not kernicterus, as the liver is still able to conjugate bilirubin, and conjugated bilirubin is unable to cross the blood-brain barrier. The cause of the condition is unknown. The only effective treatments are certain surgeries such as the kasai procedure, or liver transplantation.

Symptoms

Symptoms of Biliary Atresia
Newborns with this condition may appear normal at birth. However, jaundice (a yellow color to the skin and mucous membranes) develops by the second or third week of life. The infant may gain weight normally for the first month, but then will lose weight and become irritable, and have worsening jaundice.

Other symptoms may include:

1. Dark urine
2. Enlarged spleen
3. Floating stools
4. Foul-smelling stools
5. Pale or clay-colored stools
6. Slow growth
7. Slow or no weight gain

Causes

Causes of Biliary Atresia
The cause of biliary atresia is not known. The two types of biliary atresia appear to be a “fetal” form, which arises during fetal life and is present at the time of birth, and a “perinatal” form, which is more typical and does not become evident until the second to fourth week of life. Some children, particularly those with the fetal form of biliary atresia, often have other birth defects in the heart, spleen, or intestines.

An important fact is that biliary atresia is not an inherited disease. Cases of biliary atresia do not run in families; identical twins have been born with only one child having the disease. Biliary atresia is most likely caused by an event occurring during fetal life or around the time of birth. Possibilities for the “triggering” event may include one or a combination of the following factors:

1. infection with a virus or bacterium
2. a problem with the immune system
3. an abnormal bile component
4. an error in development of the liver and bile ducts

Diagnosis

Diagnosis of Biliary Atresia
The health care provider will perform a physical exam, which includes feeling the patient's belly area. The doctor may feel an enlarged liver.

Tests to diagnose biliary atresia include:

1. Abdominal x-ray
2. Abdominal ultrasound
3. Blood tests to check total and direct bilirubin levels
4. Hepatobiliary iminodiacetic acid (HIDA) scan, also called cholescintigraphy, to help determine whether the bile ducts and gallbladder are working properly
5. Liver biopsy to determine the severity of cirrhosis or to rule out other causes of jaundice
6. X-ray of the bile ducts (cholangiogram)

Treatment

Treatment of Biliary Atresia
An operation called the Kasai procedure is done to connect the liver to the small intestine, going around the abnormal ducts. It is most successful if done before the baby is 8 weeks old. However, a liver transplant may still be needed.

Prognosis

Prognosis of Biliary Atresia
Early surgery will improve the survival of more than a third of babies with this condition. The long-term benefit of liver transplant is not yet known, but is expected to improve survival.

Prevention

Prevention of Biliary Atresia
Consult with your doctor.