What is biliary atresia?
Bile is an important fluid produced by your child's liver and stored in the gallbladder. In a healthy system, it flows through a tube called the common bile duct to the small intestine, where it helps to digest food.
If your child has biliary atresia, the common bile duct is blocked or damaged, so that it's impossible for bile to flow through it, just as it's hard for water to pass through a clogged pipe. This is called cholestasis, or poor bile flow, and quickly leads to malnutrition and liver damage. Biliary atresia symptoms, such jaundice and dark urine, typically occur within the first few weeks of a child's life.
It is fatal if left untreated. This condition:
- is the most common cause of chronic liver disease in newborns
- occurs once in every 30,000 births
- is the most common reason for liver transplants in children
- affects children of all races and ethnicities, but may be more common in Asians
There are two main reasons why biliary atresia is a problem. First, it makes it harder for bile to get to your child’s small intestines. Without enough bile in the small intestines, it's more difficult for your child's body to absorb fat and harder for the body to get rid of certain toxins that need bile to help them exit the body.
Second, bile accumulation in the liver, causes liver damage. As this condition progresses, inflammation and scarring damage the liver more and more, eventually resulting in cirrhosis of the liver. If bile can’t leave the liver, it accumulates. This can result in a buildup of toxins that causes even more liver damage.
What are the symptoms of biliary atresia?
Infants with biliary atresia may be born with jaundice, but usually appear healthy at birth. Most often, you or your child's pediatrician will notice signs within the first few weeks of your child's life. These may include:
- jaundice (yellowing of the eyes and skin)
- dark urine
- light-colored stools
Signs that may appear later include:
- distended (swollen) abdomen
- weight loss
These are later signs, not usually in the first months of life.
What causes biliary atresia?
We know that biliary atresia is caused by inflammation and scarring of the bile ducts, but what causes the inflammation and scarring is still unknown.
There are three types of biliary atresia:
- biliary atresia without any other malformations: this is the most common type seen in ~85 percent of the babies
- biliary atresia with at least one major malformation but without laterality ~5 percent
- biliary atresia with laterality defects ~10 percent, this is what was previously called biliary atresia splenic malformation syndrome.
Biliary Atresia | Diagnosis & Treatments
How is biliary atresia diagnosed?
The first step in treating your child is forming an accurate and complete diagnosis. If your child has biliary atresia, it’s important that your child be diagnosed quickly, since surgery must be performed early in order to be effective.
Usually, the diagnostic process begins when you or your child’s pediatrician notices that your child appears jaundiced. The doctor will do one or more blood tests to determine whether it may be because of a liver problem.
These blood tests may include:
- bilirubin level test
- liver enzymes and bile duct enzymes tests
- coagulation tests
- viral tests — some viruses can cause liver damage
- tests for some metabolic diseases (such as enzyme deficiencies) that can cause early jaundice and liver test abnormalities
- tests for cystic fibrosis, such as a sweat test
The doctor may also want to check your child’s urine and stool.
He or she may also order diagnostic tests to view your child’s biliary system, including:
- abdominal ultrasound to see if there is a normal gallbladder or abnormalities that may explain the jaundice
- biliary excretion or “HIDA” scan — a special chemical is injected into your baby’s vein, then pictures are taken to see if it is excreted normally by the liver, just as bile would be
- liver biopsy — a tissue sample is taken from your child's liver and examined for abnormalities
We may also need to perform a diagnostic surgical procedure to directly see the biliary tree this is considered the gold standard to rule out biliary atresia. This is called:
- intraoperative cholangiogram — a small incision is made in your child’s abdomen, and a contrast agent is injected into her bile duct. This agent can be seen on a special monitor, helping surgeons to see any blockages in the bile ducts.
After we complete all necessary tests, our experts meet to review and discuss what they have learned about your child's condition. Then we'll meet with you and your family to discuss the results and outline the best treatment options.
What are the treatment options for biliary atresia?
While there's no medical cure for biliary atresia, your child will typically undergo an operation to restore the drainage of bile and connect the liver back with your intestine; this is called Kasai portoenterostomy. If the biliary atresia is a diagnosed late a primary liver transplant might be necessary.
During a Kasai portoenterostomy, your child's surgeon removes the damaged bile ducts and connects the liver to the intestine. This allows bile to drain directly from the small bile ducts at the edge of your child's liver straight into her intestine. Following the surgery, your child may stay in the hospital between seven and 10 days. If done within the first two to three months of your child's life, a Kasai portoenterostomy can allow her to grow and remain in fairly good health for many years.
In about 40 to 50 percent of cases, even after a successful portoenterostomy, jaundice may not go away as the inflammatory process of biliary atresia involves the bile ducts in and outside the liver. Bile won't flow, and these children will need a liver transplant early on in life.
Along with the Kasai portoenterostomy, your child's doctors will do a liver biopsy if not already done to determine the extent of your child's liver damage. It may also help predict how her condition will progress in the coming months.
After surgery, your child will need ongoing medical care and monitoring, including tests. Your child's doctor can explain to you what the tests mean, and what the signs are that your baby's liver is doing well or getting worse. The doctor will also talk to you about the complications of biliary atresia that may require a liver transplant.
A liver transplant is an operation in which the transplant surgeon removes your child's damaged liver and replaces it with a new liver.
The new liver can be the whole liver from a deceased donor, or a segment from a deceased donor or a living family member (if he or she is a suitable candidate). In the case of a living donor, the donor's liver will grow back to more or less its full size just a few weeks after the operation.
After surgery, the new liver begins functioning and the child's health often improves quickly, although transplants carry complications of their own.
Nutrition and biliary atresia
Children with biliary atresia who do not clear their jaundice have poor to no bile flow into their intestine. Since bile is important for absorption of fat this will result in poor special nutritional needs. Our registered pediatric dietitians can make recommendations including:
- feeding with special formulas that contain a kind of fat that's more easily absorbable
- adding specific vitamins to your child's diet, as directed by your child's physician
- adding MCT (medium-chain triglyceride) oil for extra calories to the diet. MCTs are absorbed as compared to LCT (long chain triglycerides), which is the most common fat that we eat. MCT oil can be added to foods and liquids that your child eats.
If your baby can't take in the amount of calories needed to maintain a normal growth rate, we may recommend extra milk/formula feedings. These are given through a tube called a nasogastric tube (NG) that is guided into the nose, down the esophagus, and into her stomach.
What is the long-term outlook for biliary atresia?
While there's no cure for the condition, there are ways for your child to have a longer and healthier life. The first step is surgery, called the Kasai portoenterostomy, in which the blocked bile duct is bypassed and your child's intestine is brought up/sewn up to the liver. Afterwards, special formulas and vitamin preparations, as well as other medications, can help your child grow and help to preserve her liver function.
Nonetheless, many children who have Kasai portoenterostomies early in life will need a liver transplant as the inflammatory process of biliary atresia involves the bile ducts in and outside the liver.
Current national statistics confirm that about 85 percent of children who have liver transplants survive the first year, and most children who survive the first year go on to live into adulthood.
How we care for biliary atresia
At Boston Children's Hospital, biliary atresia is treated by a small number of doctors with specific expertise in the Center for Childhood Liver Disease. We're known for our individualized and science-driven approach. We're home to the most extensive research enterprise located in a pediatric hospital in the world, and we partner with a number of top biotech and health care organizations.
Boston Children's is also home to New England's largest pediatric Liver Transplant Program. If your child has biliary atresia, our team will work with you from the beginning to identify the best treatment options for each stage of their condition.