Biliary Atresia (Children)

Biliary atresia is a progressive, inflammatory condition causing the destruction of the extrahepatic (outside the liver) and abnormalities of the intrahepatic (within the liver) bile ducts.

It typically manifests in the first few weeks of life. In infants with biliary atresia, bile becomes trapped inside the liver, leading to liver damage and scarring . If Untreated, this condition results in further liver deterioration and eventual liver failure, with few children surviving beyond two years of age. Biliary atresia occurs in approximately one in every 20,000 live births1, with a slightly higher prevalence in females.

Source: 1PubMed

The exact cause of biliary atresia remains unknown. Autoimmune responses may contribute to its progression. Additionally, research indicates a potential link between viral infections and biliary atresia. About 10% of cases are accompanied by other congenital defects in the heart, blood vessels, intestine or spleen.

It is crucial to understand that biliary atresia affects only newborns, is not hereditary, contagious, or preventable, and is not caused by maternal actions during pregnancy.

Typically, a full-term infant who initially appears normal develops jaundice at two to three weeks of age. Symptoms include yellowing of the eyes and skin, light-coloured stools and dark urine due to the build-up of bilirubin in the blood. The infant may exhibit an enlarged, firm liver, abdominal swelling, weight loss and increased irritability as jaundice levels increase.

To diagnose biliary atresia or identify any underlying causes for persistent jaundice in infants, several tests are necessary. These include:

• Blood tests to confirm conjugated hyperbilirubinaemia.
• Ultrasound scans of the liver and gallbladder to identify an atretic gallbladder.
• HIDA scans (radioactive imaging of the biliary system) to confirm bile flow obstruction.
• Liver biopsies to check for cirrhosis.
• A surgical procedure to examine the bile ducts to assess the possibility of a bile drainage procedure for alleviating obstruction.
  

Early diagnosis is very important. Surgery is more likely to succeed if performed before the infant reaches two months of age. The success rate diminishes significantly if the surgery occurs after the child is older than three months. Therefore, it is imperative to evaluate all infants exhibiting jaundice beyond four weeks for biliary atresia.

The primary treatment for biliary atresia is the Kasai Procedure. In this operation, a paediatric surgeon removes the obstructed bile ducts outside the liver and attaches a loop of the small intestine directly to the liver, allowing bile to flow into the intestine. This connection, known as a Roux-en-Y hepatoportojejunostomy, or the Kasai Procedure, can lead to the successful drainage of bile from the liver and the disappearance of jaundice. In such cases, children can live many years and grow normally.

Howevr, if bile flow is only partially restored, the child may eventually develop cirrhosis complications and will require a liver transplant. Some children might not need a liver transplant if they experience no bile flow after the Kasai Procedure.

Adequate bile flow is needed for the digestion and absorption of dietary fats and fat-soluble vitamins such as vitamins A, B, E and K. Reduced bile flow can lead to poor growth and malnutrition in children. To counter this, special formulas containing medium-chain triglycerides (easily digested dietary fat) and water-soluble vitamin supplements are often prescribed to optimise the child's growth and development.

About 50–60% patients experience jaundice clearance after the Kasai Procedure2. Such patients can survive over 20 years with their native liver if they undergo the operation early in infancy. However, 60.5% of them may still face progressive liver-related complications1.

Long-term complications following Kasai Procedure include cholangitis and portal hypertension. Cholangitis, an infection caused by bacteria migrating up the Roux-ex-Y, presents symptoms like fever, increased jaundice and lighter stool colouration. Treatment or prevention of cholangitis requires antibiotics.

Portal hypertension, resulting from liver scarring, leads to increased pressure in the veins linking the intestines and spleen to liver. This condition can cause bleeding and clotting problems, enlarged veins in the oesophagus and stomach and ascites—an accumulation of fluid in the abdominal cavity .

When these complications become unmanageable with medication, liver transplantation comes necessary. Liver transplantation has proven highly successful in the long-term treatment of children with biliary atresia, with an overall survival of more than 90%3.

Source: 1PubMed, 2ISRN Surgery, 3PubMed

NUH's paediatric liver transplantation unit offers a comprehensive, lifelong management for children with biliary atresia, starting with the Kasai procedure in infancy. The clearance of jaundice following this procedure is indicative of the short-term need for a liver transplant within two years or the long-term survival with the native liver.

In NUH, over 60% of patients achieve jaundice clearance. Post-transplant, children are closely monitored until adulthood. Liver transplantation may be necessary for those developing decompensated liver disease and its complications. Post-transplant survival rates for these children exceed 89.3% at one year

Information is correct as of January 2021.