What is biliary atresia?
Biliary atresia is a rare disease of the liver and bile ducts that becomes present shortly after birth. This chronic, progressive condition occurs when there is a blockage in the tubes (ducts) that allow bile to flow from the liver to the gallbladder.
Bile is a clear digestive fluid produced by the liver and stored in the gallbladder. It carries waste products from the liver to the kidneys and intestines, where they can be excreted. It also helps to break down fats during digestion.
In biliary atresia, the bile ducts inside and outside the liver are scarred and blocked. This prevents bile from flowing freely through them. As a result, it builds up in the liver, which can severely damage it and affect other vital organs.
Over time, this leads to the loss of liver tissue and function. It also scars the liver. Late-stage scarring of the liver is called cirrhosis and can be deadly if not treated. As bile stays trapped in the liver, it also backs up into the bloodstream, which can lead to a medical condition called jaundice that yellows the infant’s skin and the whites of their eyes.
What causes biliary atresia?
There is no known cause for biliary atresia. Some medical professionals and researchers believe that babies are born with the disease and that the bile duct blockage occurs during pregnancy when a baby’s liver is still developing.
Others believe that the disease is not congenial. Rather than being present at birth, they think it arises after exposure to some type of infection or toxic substance shortly after delivery.
To date, there isn’t any type of connection between the health of the mother and the onset of biliary atresia in an infant. It does not seem to be linked to any actions performed or medications taken during pregnancy, nor any type of illness that
the mother might have contracted.
This is a rare disease that occurs once in every 10,000 births and isn’t likely to occur more than one time in a family. There is no known genetic link.
Who can get it and who is at risk?
Infants who develop jaundice around two weeks of age are most likely to have biliary atresia. Asian and African-American newborns are more frequently affected by this disease than Caucasian newborns, and girls are at a higher risk than boys.
What are the symptoms of biliary atresia?
Most infants with biliary atresia appear healthy right after birth. Symptoms do not usually develop until they’re between two weeks and two months old.
Jaundice is one of the first signs and usually becomes apparent between three to six weeks of age.
Jaundice arises from an excess of the orange-yellow pigment bilirubin, which is formed in the liver by the breakdown of hemoglobin. Bilirubin is normally excreted in bile but builds up in the bloodstream of someone with jaundice.
As bilirubin levels increase, it causes the infant’s skin to turn slightly yellow, along with the whites of their eyes.
Another symptom of biliary atresia is light or clay-colored stools.
In a healthy-functioning liver, bile travels through ducts to the intestine, where it gives bowel movements a yellow, green, or brown color. The absence of bile in their intestines means an infant’s stools will be much lighter and clay-colored.
These are known as “acholic” stools.
In addition to these two symptoms, other signs of biliary atresia include:
- Dark-colored urine
- Weight loss
- Distended abdomen
A distended abdomen is one that is abnormally swollen outward. The difference is visibly noticeable and measurable and can sometimes be felt.
Many of the initial signs of biliary atresia can mimic those of other health conditions and diseases. If you notice any of these symptoms, it’s important to meet with your child’s doctor for an official diagnosis.
How is biliary atresia diagnosed?
If a doctor suspects that an infant has biliary atresia, they will obtain their medical history and conduct a thorough health exam. Then, they can conduct further tests to evaluate the cause of their symptoms. These can include both blood tests and imaging tests.
There are six primary blood tests that can confirm or deny the presence of biliary atresia in an infant. Each of these tests checks a different component of a child’s bloodstream.
Albumin is one of the proteins made by the liver. When these levels (or total protein levels) are below normal, it can be a sign of a chronic liver disease or disorder.
Elevated levels of bilirubin can indicate that an infant’s bile flow is obstructed or there is a defect in the liver’s bile-processing abilities. This pigment is normally produced in the liver and excreted through bile, which keeps levels regulated.
In a blood culture test, doctors will check for the presence of a bacterial infection in the infant’s bloodstream. They can use those results to diagnose biliary atresia.
For blood to clot successfully, the liver must produce proteins and vitamin K. If liver cells are damaged and the bile flow is obstructed, it can interfere with the liver’s ability to produce those nutrients, so clotting takes longer to occur.
Doctors can perform tests to monitor blood clotting times. Two of the most common ones include:
- Prothrombin time (PT)
- Partial thromboplastin time (PTT)
These tests measure how long it takes blood to clot in a sample. Both prothrombin and thromboplastin play critical roles in the blood coagulation process.
If an infant has elevated levels of liver enzymes in their blood, this can be a sign that their liver is either damaged or injured. When this organ is distressed, it will cause enzymes to leak from the liver into the bloodstream.
Doctors will also check for the presence of certain viruses in the infant’s bloodstream, including HIV and hepatitis. These viruses can also cause liver problems with symptoms similar to those of biliary atresia.
In addition to blood tests, there are also certain imaging tests that doctors can use to identify the presence of biliary atresia. These include an abdominal ultrasound and a Hepatobiliary (HIDA) scan.
An ultrasound uses high-frequency sound waves to produce an image of the body. With these tests, doctors can get a close-up view of internal tissues, blood vessels, and organs.
If they suspect an infant might have biliary atresia, they can create an ultrasound to get a more detailed look at their liver, gallbladder, and bile ducts.
With a HIDA scan, the doctor will inject a low-radioactive isotope called technetium into the infant’s vein. Then, they will take a scan of their liver by using a special type of device called a nuclear medicine machine.
The machine will track the isotope as it travels throughout the child’s body. If it passes through their liver and enters their intestine, it indicates that the bile ducts are open and functioning normally. This can confirm that biliary atresia is not present.
In addition to the tests above, a doctor may also order a biopsy of the infant’s liver to better understand any damage that might be occurring. A biopsy is a sample of tissue that’s taken from the body for closer analysis.
Once all of the tests are completed, they will analyze the results to determine if biliary atresia is occurring. It’s important to conduct these tests as soon as possible once symptoms start presenting, so treatment can begin immediately.
What is the treatment for biliary atresia?
Presently, there is no medication that can treat biliary atresia. The disease is irreversible and no drugs are available to unblock the blocked bile ducts or encourage the growth of new ducts.
If your child’s doctor confirms the presence of biliary atresia, they will recommend a specific type of treatment based on several different factors, including:
- Your child’s age, medical history, and overall health
- Your child’s tolerance level for certain medications, therapies, and procedures
- The extent to which the disease has progressed
- Expectations on the course of the disease
- The opinion of your child’s medical team
- Your opinion and preference as the parent
While biliary atresia is not currently curable, the two operations below can help affected children live longer, healthier, and more comfortable lives.
Also called Kasai portoenterostomy, this surgery replaces the child’s scarred bile ducts with new tubes that will allow bile to drain from the liver. These tubes connect the bile drainage path directly from the liver to the intestinal tract.
This surgery is most successful when performed on children who are younger than three months old. While it can help improve their quality of life, it doesn’t provide a permanent solution. Over time, bile will back up into the child’s liver, leading to liver damage and a condition called cholestasis.
Biliary atresia is the most common cause of liver transplantation for children in the U.S. This is a longer-lasting treatment in which surgeons will remove the child’s damaged liver and replace it with a new one from a donor.
Once a child receives the new liver, they should start feeling better shortly thereafter. To make sure their body doesn’t reject the new organ, they will need to take special antirejection medication. When the body suspects there’s something new and different inside of it, from a foreign substance to a virus, it will naturally try to reject it. The medication prevents this automatic response from occurring.
What can I expect from surgery?
There are different types of liver transplant surgeries that can occur. Your child’s doctor will determine the best course of action based on their health and needs.
Surgeons can replace the damaged liver with a whole or partial liver from a deceased donor. Or, they can replace part of the liver with another part received from a relative or other living person. To be successful, the donor’s tissue types must match the child’s tissue types.
Most children are able to go home five to seven days after the surgery. To be released, they must have a normal temperature and be able to eat and drink. They must also be able to take pain medication orally.
What can I expect after surgery?
After the liver transplant surgery, the surgeon will place a tube in your child’s nose that goes to their stomach. This tube drains fluid and prevents them from vomiting. You will also see a large incision on their belly, covered by a bandage, as well as a small drainage tube. The tube allows fluid to drain out of their body as they heal.
While their intestines heal, the child will not be able to eat for several days. They will receive sugar water through an IV, where nurses will also administer pain medication.
After three to four days, most children are well enough to have the tubes removed and eat on their own. While they will be in a hospital gown at first, you are welcome to bring their favorite soft pajamas or clothes to keep them comfortable as they heal. Soft toys, blankets, and stuffed animals are also permitted.
Once you are home, your doctor will instruct you to closely monitor the child’s bowel movements. They should gradually change from light and clay-colored to a darker green or yellow color over the course of about two weeks. This indicates that the surgery was successful, and that bile is effectively moving from the liver to the intestines.