Biliary atresia is a rare condition where the openings of the liver's bile ducts are not normal. Biliary atresia affects infants and even fetuses. It is a potentially fatal disease, and children who are not treated for it often do not live past two years of age.
Definition & Facts
The liver’s bile ducts are responsible for transporting bile to the person’s gallbladder. Bile is a greenish-brown liquid that helps the body digest fat and excrete waste. Bile also helps in the absorption of vitamin A, vitamin K, vitamin E, and vitamin D, which are fat soluble.
Because the bile ducts can’t carry bile out of the liver, it builds up in the organ and damages and scars it. This leads to cirrhosis, which eventually causes the liver to malfunction and eventually fail. In the end, the patient must have a liver transplant to survive.
Biliary atresia affects about one in 18,000 babies and is more common among females, Asian or African American babies, or babies who were born prematurely.
Symptoms & Complaints
Jaundice is an early symptom of biliary atresia. This is the yellowing of the baby’s skin and the whites of their eyes (sclera). This happens when bilirubin, a product of the breakdown of red blood cells, builds up in the liver. Usually, bilirubin is broken down by the liver and secreted into the bile, which carries it away.
Biliary atresia is congenital but is not inherited. This means it is present at birth but is not a disease that is passed down from the child’s parents. Scientists are not entirely sure of the causes of the disease but they suspect:
- A mutation in one or more genes.
- An infection the baby contracted after birth. The infection could be caused by a bacteria or a virus.
- The liver and bile ducts failing to develop properly during gestation.
- An autoimmune disease or immune response where the baby’s immune system mistakenly attacks the bile ducts or the liver.
- The mother being exposed to toxins that damage the baby in utero.
Diagnosis & Tests
Several tests are needed to make a firm diagnosis of biliary atresia. Doctors urge parents who see that their baby is still jaundiced or passing clay-colored stool after they are two weeks old to have them examined for liver damage. Tests that can help a doctor diagnose biliary atresia include:
- Blood tests. These tests can find elevated levels of bilirubin in the child’s blood. This is a sign that the ducts are not working the way they should.
- Liver biopsy. In this procedure, the doctor uses a needle to take a small piece of the baby’s liver and has it examined under a microscope. The baby will need to be sedated and given a local anesthesia for this procedure. The pathologist who examines the piece of liver should be able to tell if the liver is affected by biliary atresia or other problems.
- Imaging tests. X-rays of the child’s abdomen can find an enlarged liver (hepatomegaly). The procedure is painless, but the baby may need to be given a sedative so they can lie still while the X-ray is being taken. The doctor can also give the baby a liver scan, which is a specialized type of X-ray. The baby may also need to be anesthetized for this procedure. A radioactive dye is injected into the baby to discover blockages and show how bile is flowing in the body.
- Ultrasound is painless but is different from an X-ray in that it bounces sound waves off of the baby's organs. This creates an image of them and reveals pathologies such as tumors or structural abnormalities. Ultrasound doesn’t provide a diagnosis of biliary atresia but rules out other problems that lead to jaundice.
- Diagnostic surgery. In this type of surgery, the surgeon makes an incision in the baby’s abdomen to directly examine their liver and ducts. If the doctor finds biliary atresia, they perform a Kasai procedure while the baby is anesthetized and on the operating table.
Treatment & Therapy
In the Kasai procedure, the surgeon takes away the malfunctioning bile ducts and attaches a segment of the small intestine to the liver. This allows bile to flow directly into the small intestine. Though this operation doesn’t cure biliary atresia, it helps to ease many of the problems caused by it and also saves the child’s life.
The younger the baby is when they have the Kasai procedure, the better the outcome. This is because the liver has not had time to become permanently damaged by the biliary atresia. If the liver has been permanently damaged, the child will probably need a liver transplant before they are two years old.
A number of children still develop cirrhosis even with the Kasai procedure. These children will eventually need a liver transplant when they grow up. Babies who contracted biliary atresia in the womb often need a liver transplant at younger ages than babies who contracted the disease after birth.
Advances in surgical technique make it possible for a child to receive a part of an adult liver. The liver can regenerate more than any other organ, so the child may eventually be able to grow a portion of the liver that has been removed.
Children with biliary atresia need special diets to make up for the deficiencies that are caused by their condition. The diets are often high calorie and are fortified with vitamins and triglyceride oils.
Prevention & Prophylaxis