Biliary atresia

Definition

Biliary atresia is an obstruction of the bile ducts caused by their failure to develop normally in the fetus. This is a congenital condition (present at birth).

Causes, incidence, and risk factors

Biliary atresia is caused by the abnormal development of the bile ducts inside or outside the liver. The purpose of the biliary system is to remove waste products from the liver, and to carry bile salts necessary for fat digestion to the small intestine.

In babies with biliary atresia, bile flow from the liver to the gallbladder is blocked. This can lead to liver damage and cirrhosis of the liver, which, if not treated, will eventually be fatal.

Newborns with this condition may appear normal at birth but jaundice develops by the 2nd or 3rd week of life. The infant may gain weight normally for the 1st month, then weight loss and irritability develop, accompanied by increasing levels of jaundice. It is not known why the biliary system fails to develop normally.

Symptoms

• Jaundice, a yellow color of the skin and eyes
  • May be present at birth or develop over several months
  • May be progressive or intermittent
• Slow or absent weight gain
• Slow growth in a child 0 - 5 years old
• Irritability
• Dark urine
• Splenomegaly (enlarged spleen)
• Pale or clay-colored
• Floating stools
• Foul-smelling stools

Signs and tests

During a physical examination, the doctor may detect an enlarged liver.

Tests that reveal biliary atresia include:

• Increased bilirubin in the blood
• Abdominal x-ray shows an enlarged liver and spleen
• Abdominal ultrasound
• HIDA scan (nuclear test to determine bile flow)
• Cholangiogram to determine patency of ducts
• Liver biopsy to determine degree of cirrhosis or to rule out other causes of jaundice

Treatment

An operation called the Kasai procedure is done to connect the liver to the small intestine, bypassing the malformed ducts. It is most successful if performed before the baby is 10 - 12 weeks old. However, a liver transplant may still ultimately be required.

Expectations (prognosis)

Early surgical intervention will improve the survival of more than one-third of those affected by the condition. The long-term benefit of liver transplant is not yet known, but is expected to improve survival.

Complications

• Liver failure
• Infection
• Surgical complications
• Failure of the Kasai procedure
• Irreversible cirrhosis

Calling your health care provider

Call your health care provider if your child appears jaundiced, or if other symptoms suggestive of this disorder develop.

Illustrations

Digestive system

Bile produced in the liver

Page Content:

atresia biliary; atresia biliary pathophysiology; atresia biliary extrahepatic