Biliary Atresia

What is biliary atresia?

Biliary atresia (pronounced BILL-ee-air-ee ah-TREE-zhuh) is a liver condition. It occurs when a baby's bile ducts do not form normally. Instead of being open tubes to drain bile from the liver, the bile ducts are missing or they are blocked because of scarring.

Bile is a liquid made by the baby's liver. It helps the body digest (break down) fats. Normally, bile flows through tiny bile ducts within the liver into larger ducts that lead to the gallbladder and intestine. The gallbladder stores bile until the body needs it to digest food. Food triggers the gallbladder to contract and squeeze bile out into the intestine.

In babies with biliary atresia, the abnormal or scarred bile ducts keep bile from flowing out of the liver. Instead, bile backs up in the liver. Backed-up bile (congestion) in the liver is called cholestasis. It causes scarring (cirrhosis) and jaundice, or a yellowish tint to the skin and eyes. This is because bile contains a yellow pigment, called bilirubin.

Biliary atresia in children

About 1 baby in 15,000 has biliary atresia. Doctors do not know why it occurs. In most cases, it is present early in infancy. Usually it's found in the first 1 to 2 months of life. If it's not found until after 2 months of age, it seems to progress to worse disease.

The bile ducts may be abnormal when the baby is born (congenital). In some babies, the bile ducts may not form correctly while the baby is developing. A small number of babies with biliary atresia (about 15%) may have other structures that did not form normally – their intestine, spleen and portal vein, which goes to the liver.

In some babies, the ducts form but cells that cause swelling (inflammation) may collect around the ducts. The inflammation may make the ducts swollen and narrower, closing them off and creating scars.

Surgery to remove blockage

In order to survive, babies with biliary atresia need surgery. This is usually done in the first 2 months after birth. The goal is to remove any blockage in the ducts outside the liver and create a way for bile to drain straight from their liver into their intestines. This surgery is called the Kasai procedure. It is named after Dr. Morio Kasai of Sendai, Japan, who developed the surgery in the 1960s.

Liver transplant

Without surgery, biliary atresia leads to liver failure. A baby with liver failure may be able to have a liver transplant. Biliary atresia is the most common reason for liver transplants in children. It accounts for nearly half of them.

Biliary Atresia at Seattle Children's

  • The experts you need are here

    We have treated many babies with biliary atresia. Our surgeons are experienced at performing the Kasai procedure that creates direct drainage for bile from the liver into the intestine (portoenterostomy). Each year, our surgeons perform 4 to 6 of these surgeries.

    At Seattle Children's, we have the only pediatric liver transplant program in the Pacific Northwest. The outcomes of our well-regarded program are among the best in the nation.

  • Your child and family get support

    When you come to Seattle Children's, you have a team of people to care for your child before, during and after surgery. Along with your child's surgeon, you are connected with doctors trained to care for newborns with complex problems (neonatologists), doctors who specialize in stomach, intestine and liver diseases (gastroenterologists and hepatologists), nurses, dietitians, child life specialists, social workers and others. We work together to meet all of your child's health needs and help your family through this experience.

  • We are trained to meet the unique needs of children

    Since 1907, Seattle Children's has been treating children only. Our team members are trained in their fields and also in meeting the unique needs of children. For example, the doctors who give your child anesthesia are board certified in pediatric anesthesiology. This means they have extra years of training in how to take care of kids. Our child life specialists know how to help children understand their illnesses and treatments in ways that make sense for their age.

Symptoms of Biliary Atresia

  • Yellowish eyes and skin

    Biliary atresia causes yellowish eyes and skin (jaundice) that lasts more than 2 weeks after birth. Usually the jaundice does not appear until after the first week of life.

    It's also common for healthy babies to have jaundice soon after they're born. Normally this clears up within the first 2 weeks. If your baby has jaundice longer, see your baby's doctor to find out why. Other conditions besides biliary atresia can cause jaundice to linger.

  • Pale stools

    Babies with biliary atresia also have very pale or gray (acholic) stools. Bile gives stools their usual yellow, green or brown color. If bile cannot flow out of the liver into the intestine, your child's stool will not have these colors. Instead, bile becomes backed up in their liver (cholestasis). This increases the amount of the pigment bilirubin in their blood. It gets passed out in their urine. This can make their urine darker than normal.

  • Scarring of the liver

    If a baby with biliary atresia does not get treatment within the first couple of months after birth, scarring of the liver (cirrhosis) can occur. This scarring cannot be reversed. Cirrhosis can cause other symptoms, like fluid collecting in the belly (ascites) and an enlarged spleen.

Diagnosing Biliary Atresia

If your baby's doctor suspects biliary atresia, the doctor will start with a thorough exam and will ask about your baby's health background. Then the doctor will ask for blood tests to tell how your baby's liver is working and to check bilirubin levels.

Body imaging

Your baby's doctor may also want to have pictures taken of the inside of your baby's body, such as an ultrasound and a hepatobiliary iminodiacetic acid (HIDA) scan. A HIDA scan allows doctors to see whether a special dye that collects in the liver can pass out of the liver through the bile ducts.


To learn more about your baby's liver and bile ducts, the doctor may order a biopsy. This could mean drawing some cells from your baby's liver with a syringe (needle biopsy) or doing surgery to remove a small sample of your baby's liver.

If these tests suggest bile flow is blocked, then surgery is done in most cases. During surgery, doctors can check how well the bile ducts developed and can diagnose atresia.

Treating Biliary Atresia

Babies with biliary atresia need surgery to remove any blockage in the bile ducts outside the liver and create a way for bile to drain straight from their liver into their intestines. The surgery is called a Kasai procedure (portoenterostomy).

  • Kasai procedure

    During a Kasai procedure, the surgeon removes the scarred, abnormal bile ducts outside of the baby's liver. Then the surgeon creates an extension of the small intestine, called a roux-en-Y (pronounced ROO-enn-WHY), that can reach up to the liver. The surgeon connects this extension to the liver at the place where the bile ducts come out of the liver.

    The Kasai procedure tends to be more successful the earlier it's done. Usually the goal is to complete the surgery in the first 2 months after birth. The surgery may also be helpful for older babies, if they don't already have advanced liver disease.

    Some children will recover with good liver function and bile flow after a Kasai procedure. Some will do well for a while, even a few years, and then their liver damage will get worse and their liver will fail. Then they will need a liver transplant.

    Preparing for your child’s surgery

    You can read about what to expect when your child visits a clinic at Children's, has surgery here or needs to stay in the hospital. You can get practical details about topics like what to do and bring the day of surgery and who will be on your child's care team.

  • Liver transplant

    For some children, a Kasai procedure will not help because their liver has too much damage. These children will need a liver transplant so they have a chance to survive.

    Seattle Children's has the only pediatric liver transplant program in the Pacific Northwest. We have been performing liver transplant surgery since 1990.

Contact Us 

Contact Seattle Children’s Gastroenterology and Hepatology Department at 206-987-2521 for a referral, a second opinion or more information.

Providers, see how to refer a patient.