Biliary Atresia
In Episode 708, "Something's Gotta Give," we meet Baby Lisa who suffers from biliary atresia, already needing a liver transplant at the incredibly young age of four months. And due to the fortunate fact that not many baby-sized livers become available on a frequent basis, Lisa accepts a liver from an adult donor. In these cases, when an infant is allocated an adult liver, the organ will be split in half into TWO livers and save TWO babies' lives. But even though Lisa received one of these split-grafts, the piece was still too big to fit into her abdomen—the surgical team could not successfully close it without compressing vital blood vessels. Until Alex Karev started thinking outside the box...
Why did Baby Lisa need a liver transplant when she was only four months old?
Baby Lisa suffered from a serious yet rare disease (It only affects 1 in 10,000 children) of the liver, biliary atresia, which affects newborn infants. It is the most common reason that children need liver transplantation in the United States. In our bodies, cells within our livers produce a liquid called bile that helps to digest fat. Bile also has the responsibility of carrying waste products from the liver to the intestines for excretion. However, when a child struggles with biliary atresia, this system of bile transportation? Is blocked. The bile remains trapped inside the liver, quickly damaging and scarring the liver cells (a process called cirrhosis), leading to liver failure.
What causes biliary atresia?
Sadly, we still do not completely understand what leads to the disease. However, we do describe the disease in two types—a "fetal" form and a "perinatal" form. Fetal biliary atresia develops during the fetal life and can be diagnosed at birth; the disorder also can be associated with other birth defects present in the heart, spleen, or intestines. But perinatal biliary atresia, which occurs more frequently, is not seen until the second to fourth week of life.
Unlike many childhood disorders, biliary atresia is not an inherited disease. Physicians do not see multiple children in the same family with it, and in cases of identical twins, only one child may be diagnosed with it. A likely theory exists in that the disease stems from an event that occurs during the fetal life or around the time of birth. Potential events could be an abnormal bile component, an infection from a virus or bacteria, a problem with the immune system, or an irregularity in the development of the liver and bile ducts.
What symptoms may indicate the disease?
Initially at birth, affected infants could seem perfectly healthy. Symptoms sometimes do not begin until two weeks to two months later. One of the primary signs of the biliary atresia is jaundice—a yellow coloring of the skin and whites of the eyes due to a very high level of bilirubin (bile protein) in the bloodstream. Usually, the liver takes up the bilirubin and releases it into bile. But when the ducts have become blocked, the bilirubin remains in the bloodstream. Note, many newborn infants exhibit jaundice during the first two weeks of life because the liver has not completely matured. However, if that jaundice does not disappear after a couple of weeks, parents should take their babies to the doctor.
Other symptoms include dark urine, which also signifies a build-up of bilirubin in the blood. The kidney is supposed to filter that bilirubin and remove it from the urine in normal circumstances. Weight loss, irritability, and clay-colored stools also can be clues to problems with the infant's liver.
And how do the doctors diagnose it?
Other liver disorders besides biliary atresia can cause jaundice, so appropriate tests should be done for confirmation.
- Blood tests can indicate any abnormality in the liver functions as well as distinguish the cause of the jaundice.
- X-rays of the abdomen help detect an enlarged liver or spleen.
- An abdominal ultrasound can reveal the size of the gallbladder.
- A nuclear test, called a HIDA scan, determines the flow of bile. To perform the scan, radioactive dye will be injected into the infant's vein to act like bilirubin and illuminate any blockages.
- Doctors can perform a liver biopsy to take a very small sample of the liver to study under a microscope.
- Diagnostic surgery allows surgeons to see whether an injured piece of the bile duct exists.
What kinds of treatments exist for this condition?
If the medical team confirms the infant suffers from biliary atresia, the first line of treatment will be a surgery called the Kasai procedure (a hepato-porto-enterostomy). In this operation, they remove the bile ducts and bring a loop of intestine up to replace the bile ducts and drain the liver. Therefore, bile flows from the small bile ducts straight into the intestine, bypassing the need for the larger bile ducts entirely. In many cases, this solution works successfully to restore bile flow and allow the child to live a healthy life without liver problems. However, in some patients, the Kasai procedure does not succeed, and these children go on to develop further cirrhosis and liver disease, leading them to need a liver transplant within the first or second year of life.
In the past, only livers of small children could be donated to biliary atresia patients requiring transplantation. But now with the recent advances in donor organ availability, more children with the disease are going on to lead longer and full lives. Researchers developed a way to use part of an adult donor's liver, called "reduced size" or "split liver" transplants for these patients. A cadaver liver may be split into two pieces (essentially for two patients), or a living donor may give part of their own liver. Since healthy liver tissue grows so quickly, both donor and recipient will soon have complete livers after a period of time.
After surgery and recovery, the baby will need to be placed on immunosuppressant medication to prevent rejection of the new organ. Doctors also may choose to prescribe a certain diet, vitamins, blood pressure medication, and antibiotics.
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