Definition and Overview
Biliary atresia is a serious condition that affects infants. It is characterized by hepatic bile ducts, the bile ducts in the liver that do not have the normal openings needed to function properly. The bile ducts in the liver are responsible for carrying bile to the gallbladder and the small intestine. Bile plays a key role in the body as it helps to digest and absorb fats and other nutrients, especially fat-soluble ones namely vitamins A, D, E, and K. It also carries out unnecessary waste products from the body. However, without the normal openings of the bile ducts, the bile accumulates in the liver, threatening to damage it. If left untreated, it may lead to cirrhosis, tissue damage, or even life-threatening organ damage.
Causes of Condition
Biliary atresia does not have a proven and definite cause, but doctors have linked it to several possible risk factors. However, despite its nature as a fetal disease, it is not known to be an inherited condition, which means that if a child grows up to overcome and survive from biliary atresia, he will not pass the condition on to his children.
The disease, instead, is known to begin during the development in the womb or right after childbirth.
When developed in the womb, it may be caused by:
- Genetic mutation
- Abnormal liver or bile development
- Mother’s exposure to toxic chemicals during pregnancy
When developed after birth, it may be caused by:
- Bacterial or viral infection shortly after birth, e.g. rotavirus or cytomegalovirus, among others
- Compromised immune system, wherein the immune system attacks the liver and bile ducts, usually for no apparent reason
Biliary atresia comes in two forms, namely perinatal and fetal. Perinatal atresia, the more common type, is when the disease is diagnosed or starts showing symptoms between the 2nd and 4th week following birth. On the other hand, fetal atresia is when the disease is already detected while the baby is still in the womb. In many cases of fetal atresia, it is also accompanied by other birth defects often affecting the intestines, the spleen, or the heart.
For perinatal atresia, the earliest symptoms of the condition include:
Jaundice – This is characterized by the yellowing of the skin, and is most easily detected if the whites of the eyes also take on a yellowish hue. This generally signals that the liver is not able to filter out some substances, particularly bilirubin, from the blood because the ducts are blocked.
Pale or whitish stools – This shows that the bilirubin from the liver is no longer reaching the intestines.
Dark urine – This is a sign that bilirubin, which has already spilled into the blood, is also already spilling into the urine.
Children suffering from biliary atresia may also suffer from a slowed weight gain, which may affect their growth and development.
A patient who is suspected of having biliary atresia will have to undergo some tests for the condition to be diagnosed. These include:
In some cases, surgery may be necessary to confirm a diagnosis. If confirmed, treatment may also be performed at the same time.
Who to See and Types of Treatments Available
Children who are suffering from the symptoms of biliary atresia should be brought to a pediatrician immediately. Those who are diagnosed with biliary atresia will then be referred to a pediatric hepatologist or a pediatric surgeon. A hepatologist is a medical professional specializing in the diagnosis and treatment of liver diseases.
There are some possible treatment options that can treat the condition. These include:
- Kasai procedure – A Kasai procedure is the primary form of treatment for the disease. In this procedure, the damaged bile ducts are removed and replaced using a small part of the intestines so the bile will flow through. This is not considered to be a curative procedure, but it allows bile to flow into the small intestines, relieving many of the symptoms of the disease, such as jaundice. It can also significantly lessen the risk of liver damage. This procedure is best performed before the child passes the 3rd-month mark to ensure that the liver is not yet permanently damaged. However, if a Kasai procedure is not performed in a child with biliary atresia, the patient will not be expected to live beyond the age of 2. Kasai procedure is linked to various complications, including:
- Portal hypertension
- Bacterial cholangitis
- Nutritional deficiencies
- Liver transplant – If it is too late for a Kasai procedure or if the procedure failed to protect the liver from getting damaged, the only remaining option is a liver transplant. There are also some cases wherein the Kasai procedure was deemed successful but the patient still developed cirrhosis of the liver. A liver transplant can cure the disease, and thanks to advances in surgical technology, pediatric patients suffering from biliary atresia may receive a small part of a donor liver from a living adult, instead of having to wait for a liver from deceased children. Since liver tissue grows quickly, the infant will have a complete liver in due course. Due to these advances, the success rates of liver transplant among biliary atresia patients have increased significantly over the years, and more and more patients successfully overcome the disease and survive into adulthood.
For patients who undergo a liver transplant, there is a small risk that the immune system will reject the new liver. In order to avoid this, the patient will be given some medications and may be prescribed with a special diet. Some medications, such as antibiotics, blood pressure medications, and fat-soluble vitamin supplements, may also be necessary.
- A-Kader HH, Balistreri WF. Neonatal cholestasis. In: Kliegman RM, Behrman RE, Jenson HB, Stanton BF, eds. Nelson Textbook of Pediatrics. 19th ed. Philadelphia, PA: Saunders Elsevier; 2011:chap 348.1.