The cause of biliary atresia is unknown. Some experts believe that babies are born with biliary atresia, which means the problem with the bile ducts happened during pregnancy while the liver was developing. Others believe that the disease begins after birth, and may be caused by exposure to infections or toxic substances.
Biliary atresia does not seem to be linked to medications the mother took, illnesses the mother had or anything else the mother did during her pregnancy. Currently, there is not a genetic link known for biliary atresia. The disease is unlikely to occur more than once in a family.
Biliary atresia occurs once in every 18,000 births and is more common in girls than in boys. Asian newborns, African American newborns and premature infants are more frequently affected than Caucasian newborns.
Infants with biliary atresia usually appear healthy at birth. Symptoms typically develop between two weeks and two months of life, and may include:
- Light colored stools
- Dark urine
- Distended abdomen
- Weight loss.
Symptoms of biliary atresia may resemble other liver conditions or medical problems. Please consult your child’s doctor for a diagnosis.
Your child’s doctor will perform a medical history and may order several tests including:
- Liver enzymes. Elevated levels of liver enzymes can alert health care providers to liver damage or injury, since the enzymes leak from the liver into the bloodstream under these circumstances.
- Bilirubin. Bilirubin is made by the liver and is excreted in the bile. Elevated levels of bilirubin often mean bile flow is blocked or there is a defect in the processing of bile by the liver.
- Albumin and total protein. Below-normal levels of proteins made by the liver are associated with many chronic liver disorders.
- Clotting studies, such as prothrombin time (PT) and partial thromboplastin time (PTT). These tests measure the time it takes for blood to clot. Blood clotting requires vitamin K and proteins made by the liver. Liver cell damage and bile flow obstruction can both interfere with proper blood clotting.
- Viral studies, including hepatitis and other bloodwork. Checking for viruses in the bloodstream can help determine the cause of the liver problems, as it is also important to rule out other causes that can mimic jaundice, cholestasis and biliary atresia.
- Abdominal ultrasound. This diagnostic imaging technique uses high-frequency sound waves and a computer to create images of blood vessels, tissues and organs. Ultrasounds are used to view the liver, gallbladder and bile ducts.
- Hepatobiliary (HIDA) scan. A low radioactive isotope (technetium) is injected into the child’s vein. The liver and intestine are scanned by a nuclear medicine machine. If the isotope passes through the liver into the intestine, the bile ducts are open and the child does not have biliary atresia.
A liver biopsy may also be done. This is a tissue sample taken from your child’s liver and examined for abnormalities, allowing biliary atresia to be distinguished from other liver problems. Diagnostic surgery such as an intraoperative cholangiogram is another option as it is the most definitive diagnosis. The surgeon can see the liver and bile ducts by making a cut in the abdomen. If biliary atresia is diagnosed, the surgeon may treat it at the same time. Learn more about liver biopsy.
Biliary atresia is an irreversible problem. There are no medications that can be given to unblock the bile ducts or to encourage new bile ducts to grow where there were none before. However, two different operations can be done that will allow a child with biliary atresia to live longer and have a better quality of life. Your child’s doctor can help determine whether either of these operations are an option:
- Kasai portoenterostomy. This operation connects the bile drainage from the liver directly to the intestinal tract. It is most successful when done before an infant is three months old. This procedure is helpful because it can allow a child to grow and remain in fairly good health for several years. Eventually, cholestasis (backup of bile in the liver) will occur, causing liver damage.
- Liver transplant. A liver transplant operation removes the damaged liver and replaces it with a new liver from a donor. The new liver can be either:
– A whole liver, received from a deceased donor
– Part of a liver, received from a deceased donor or
– Part of a liver, received from a relative or other person whose tissue type matches the child’s tissue type.
Before your child has either one of these operations, nutrition may be a problem. With biliary atresia, not enough bile reaches the intestine to help digest fats in the diet. Protein and vitamin deficiencies may occur due to liver damage. Children with liver disease require more calories than a normal child because of a faster metabolism.
At CHOC Children’s, our specially trained dietitians work with patients and their families to make sure children get the right nutrients. General guidelines may include:
- Providing your child with a good, well-balanced diet.
- Supplementing your child’s diet with vitamins, as directed by your child’s doctor.
- Providing your child with high-calorie liquid feedings, as directed by your child’s doctor. Some children with liver disease become too sick to eat normally. In this case, your doctor may recommend that your child have liquid feedings given to help meet his or her body’s requirements. These feedings are given through a tube called a nasogastric tube (NG) that is guided into the nose, down the esophagus and into the stomach. A high-calorie liquid can be given through the tube to supplement your child’s diet if he or she is able to eat only small amounts of food, or to replace meals if your child is too sick to eat. Learn more about enteral feeding.
- If your child is unable to tolerate NG feedings, the doctor may recommend TPN (total parenteral nutrition or “IV nutrition”) in order to make sure the child gets the nutrition he or she needs to continue growing. TPN is nutrition given to a child through a central line or a peripherally inserted central catheter (PICC). Learn more about TPN.
After surgery, your child’s digestion may return to normal, or you may still need to give extra vitamins and/or work with your child’s diet. Please consult your child’s doctor for recommendations.
Many factors affect the long-term outlook for these children. Some of them include:
- The extent of bile duct damage
- The extent of liver damage that has occurred
- The age at which either a Kasai portoenterostomy or liver transplant is done
- The overall health of the child.
After a liver transplant, the child’s health will usually improve. However, a rigorous medical regimen must be followed.