Biliary atresia

Overview

Biliary atresia is a rare liver condition that is diagnosed in babies soon after birth. In biliary atresia, a baby's bile ducts are missing, abnormal, or blocked due to extensive scarring and inflammation. This prevents bile (a fluid that helps with digestion) from draining into the small intestine. The backup of bile in the liver in biliary atresia leads to liver damage and can also cause cirrhosis (scarring).

In the United States, biliary atresia affects between 1 in 10,000 and 1 in 20,000 babies per year and is the most frequent reason for liver transplantation during childhood. In the most common form of biliary atresia, symptoms typically appear within eight weeks after birth. Without treatment, the condition is life-threatening, but patients who receive treatment (either surgery to restore the flow of bile or a liver transplant) are expected to survive into adulthood.

The cause of biliary atresia is unknown, but may relate to problems with bile duct development or an infection or harmful chemical exposure around the time of birth.

UCSF providers have decades of experience with surgical treatment for biliary atresia, including liver transplantation, and are conducting research to better understand what causes the condition.

Signs and symptoms

The first signs of biliary atresia are typically pale-colored stools and jaundice, which is a yellowing of the skin and white parts of the eyes. Jaundice may develop gradually between two and three weeks after birth.

Babies with biliary atresia also tend to stop gaining weight or begin to lose weight several weeks after they are born.

Other symptoms may include:

• Dark or amber-colored urine
• Swollen belly
• Irritability

Diagnosis

Your child's health care provider will ask about symptoms and conduct a physical exam to check for an enlarged liver. A blood sample will also be collected to measure levels of bilirubin, a substance that builds up in the body when bile ducts are blocked.

Your child's provider may also order one or more of the following tests:

• Abdominal ultrasound. This imaging test helps determine whether the liver and other digestive organs are enlarged because of fluid buildup.
• Hepatobiliary iminodiacetic acid (HIDA) scan. This imaging method shows the flow of bile through the liver, gallbladder and intestines and can help identify a blockage.
• Abdominal MRI scan. Magnetic resonance imaging (MRI) can also be used to help determine whether biliary atresia is blocking the flow of bile.
• Liver biopsy. A needle is used to remove a tiny tissue sample from the liver, and the sample is examined under a microscope.

If your child's provider suspects biliary atresia, the next step is to confirm the diagnosis with a cholangiogram, a specialized X-ray study that allows your child's provider to view bile ducts in real time.

During this procedure, your child's surgeon will inject a contrast dye (one that shows up on X-rays) into the gallbladder through a small incision. If the dye does not flow through bile ducts into the intestine, a diagnosis of biliary atresia is confirmed.

Treatment

When a diagnosis of biliary atresia is confirmed, the first treatment step is a surgical approach known as the Kasai procedure, or portoenterostomy, during which your child's surgeon reconnects the liver to the small intestine. The goal of this surgery is to restore the flow of bile from the liver into the intestine. If the Kasai procedure does not restore bile flow, your child may need a liver transplant.

Kasai procedure (portoenterostomy)

In the Kasai procedure, the surgeon removes abnormal or damaged bile ducts and the gallbladder. The liver is then connected directly to the intestine using a small piece of the intestine. This provides a new pathway for the bile to drain. The Kasai procedure is most successful if it is performed before the patient is 8 weeks old.

After surgery, your child's provider will closely monitor growth, development and liver function. The Kasai procedure eliminates the most severe symptoms of biliary atresia in about two-thirds of babies, though they will still require long-term monitoring, and some may need a liver transplant later in life. About one-third of children with biliary atresia continue to have problems with bile accumulation and will need a liver transplant in early childhood because of the ongoing damage and scarring.

Liver transplantation

Depending on the extent of the damage to the liver and bile ducts, your child may need a liver transplant.

Liver transplantation is highly successful in treating biliary atresia, helping children live well into adulthood. Your child may receive a healthy liver from a deceased donor or part of the organ from a living donor.