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Biliary Atresia

Last updated May 16, 2018

Approved by: Maulik P. Purohit MD, MPH

Learn about Biliary atresia. This video covers the known pathophysiology, important clinical signs and symptoms, and a surgical treatment called the Kasai procedure.

What are the other Names of this Condition? (Also known as/Synonyms)

  • BA (Biliary Atresia)
  • Extrahepatic Ductopenia
  • Progressive Obliterative Cholangiopathy

What is Biliary Atresia? (Definition/Background Information)

  • Biliary Atresia (BA) is a rare condition affecting infants, in which the bile ducts are damaged and blocked, resulting in a buildup of bile in the liver and low levels in the small intestine
  • Excess bile in the liver causes liver damage and could possibly lead to cirrhosis. Less bile in the small intestine causes malabsorption of fats and fat-soluble vitamins
  • The cause of blocked and damaged bile ducts has not been confirmed. However, infection, toxic substances, abnormal development of liver and bile ducts, and an irregular immune system are some of the hypothesized causes
  • The main sign of Biliary Atresia is jaundice. Other symptoms include dark urine, light-colored stool, swelling of the abdomen, and weight loss. Since jaundice is a symptom of many conditions, several tests and procedures including ultrasound scan, HIDA scan, liver biopsy, and operative cholangiogram may be performed to diagnose Biliary Atresia
  • Currently, the two available treatment measures for Biliary Atresia are the Kasai procedure and liver transplant; both of them are surgical procedures. Children, who undergo a successful Kasai procedure, may have to undergo a liver transplant later in their life
  • Special diets may be needed for individuals in whom the liver transplant is unsuccessful. If treated adequately and appropriately, most individuals live into adulthood

Who gets Biliary Atresia? (Age and Sex Distribution)

  • Biliary Atresia is only reported in infants; the incidence rate is approximately 1 in 18,000-20,000 infants
  • The condition is more common in infant girls than boys
  • African American and Asian infants are reported to be more susceptible to the condition

What are the Risk Factors for Biliary Atresia? (Predisposing Factors)

Some known risk factors for Biliary Atresia include:

  • Premature birth
  • Being a female infant
  • Being an African American or Asian infant
  • Presence of congenital syndromes and other congenital defects

It is important to note that having a risk factor does not mean that one will get the condition. A risk factor increases ones chances of getting a condition compared to an individual without the risk factors. Some risk factors are more important than others.

Also, not having a risk factor does not mean that an individual will not get the condition. It is always important to discuss the effect of risk factors with your healthcare provider.

What are the Causes of Biliary Atresia? (Etiology)

The exact cause of Biliary Atresia is not known.

  • However, scientific research indicates that BA could be triggered by events that occur during prenatal development or immediately after birth that might include:
    • A viral or bacterial infection
    • A defect in the immune system causing it to attack the infant’s own bile ducts
    • Irregular development of the liver or bile ducts during gestation
    • Exposure to toxic substances that damage the bile ducts
  • The possible triggers (mentioned above) are believed to cause inflammation and scarring of the bile ducts, thus partially or fully blocking them; this may result in low levels of bile in the small intestine and higher levels in the liver

What are the Signs and Symptoms of Biliary Atresia?

The main symptom of Biliary Atresia is jaundice. Jaundice is the yellowing of the skin and the white portion of the eyes. It is caused by the accumulation of bilirubin in the liver; a yellow pigment that is a component of bile.

  • If an infant has jaundice 2-3 weeks after birth, this may indicate the presence of Biliary Atresia
  • Dark-colored urine (owing to excess bilirubin via blood in urine)
  • Light-colored stool (gray or white, due to reduced bilirubin in the intestine)
  • Swollen abdomen
  • Delayed weight gain
  • The signs and symptoms appear anywhere from 2 to 8 weeks following birth of the child

There may be other associated congenital defects/abnormalities such as:

  • Multiple spleens (polysplenia)
  • Abnormality of the inferior vena cava
  • Presence of preduodenal portal vein
  • Heart abnormalities
  • Malrotation of the intestine (or situs inversus)

How is Biliary Atresia Diagnosed?

The diagnosis of Biliary Atresia generally requires multiple tests and procedures. Usually, the presence of jaundice after the child is 3 weeks old might indicate some sort of liver problem, but not necessarily BA. To conclusively diagnose the condition, further exams and procedures may be performed, which may include:

  • Ultrasound of the abdomen: This test will determine if any structural damage to the liver or bile ducts has occurred
  • Hepatobiliary iminodiacetic acid (HIDA) scan: It allows a healthcare provider to determine if the flow of bile from the liver to the small intestine via the bile ducts is taking place normally
  • Blood tests to determine bilirubin and liver enzyme levels
  • Blood cultures and viral tests to check for bacterial and viral infections, if any
  • Tests to detect metabolic diseases and cystic fibrosis
  • Liver biopsy: A sample of liver tissue is taken and examined in a laboratory for any abnormalities
  • Operative cholangiogram: This procedure is normally performed when the healthcare professional suspects Biliary Atresia as the most likely cause of the symptoms and wants to confirm the diagnosis. In this procedure, a contrast dye is injected into the gallbladder and the flow of the dye is monitored to observe the location of blockages, if any

Many clinical conditions may have similar signs and symptoms. Your healthcare provider may perform additional tests to rule out other clinical conditions to arrive at a definitive diagnosis.

What are the possible Complications of Biliary Atresia?

The complication of Biliary Atresia is typically due to the backup of bile in the liver and consequent reduction of bile in the small intestine. The complications might include:

  • Damage to liver tissue resulting in scarring and inflammation in the liver may occur. If left untreated, this eventually leads to cirrhosis and can cause liver failure
  • The lack of bile in the small intestine makes it harder for fats to be digested and absorbed. Also, fat-soluble vitamins, such as vitamins A, D, E, and K, have a difficulty of being absorbed. Malabsorption of fats may result in malnutrition
  • Easy bruising and bleeding
  • Retention of fluid in the body
  • Development of varicose veins in the stomach and esophagus

How is Biliary Atresia Treated?

Surgery is the only treatment available for Biliary Atresia. There are two types of surgeries that may be used for the treatment of BA:

  • Kasai portoenterostomy:
    • The Kasai procedure is named after Dr. Morio Kasai, who developed the procedure. It involves replacing the blocked bile duct with a new duct; generally a fragment of the small intestine. This allows the bile to flow uninterrupted to the small intestine
    • Without this procedure, infants with BA are not likely to live for more than two years. Even with this procedure, individuals will most likely have to get a liver transplant as adults, due to the development of liver cirrhosis
    • Also, if the Kasai procedure is unsuccessful, a liver transplant is needed. The procedure should be done before the infant is three months old because permanent liver damage has not occurred by that stage
    • The Kasai Procedure is considered before a liver transplant; however, when bile duct inside the liver is blocked, a liver transplant is the only viable treatment option
  • Liver transplant:
    • Liver transplants can occur from both infant donors and adult donors. Adult donors have much bigger livers; however, a split-liver transplant solves this problem. In a split-liver transplant, the newborn only gets a piece of the liver, and both the donor and the infant can grow functional livers after a period of time
    • The liver transplant usually requires medications and everything else that goes with organ transplants in general
  • A carefully planned nutrition plan consisting of:
    • A healthy diet
    • Adequate vitamins and minerals
    • Including the placement of a nasogastric tube, if necessary

How can Biliary Atresia be Prevented?

  • There are no methods or guidelines available at this time for the prevention of Biliary Atresia
  • One way of minimizing the risk of BA in a newborn is (for the expectant mothers) to avoid toxic or infectious substances that can potentially damage the bile ducts

What is the Prognosis of Biliary Atresia? (Outcomes/Resolutions)

  • Without any treatment, the prognosis of Biliary Atresia is poor. The affected infant may die by or before the age of 2 years
  • If a Kasai procedure is performed successfully, the infant can become healthy and the prognosis is improved. However, in many individuals, a gradual liver damage takes place, which usually necessitates liver transplant later on in life
  • Individuals who have undergone successful liver transplants go on to lead healthy lives, well into adulthood. However, in some cases, there may be complications due to the transplant

Additional and Relevant Useful Information for Biliary Atresia:

  • Biliary Atresia is not an inherited condition and family history is not a risk factor for the same
  • Individuals with Biliary Atresia who have not undergone a liver transplant often require a modified diet that includes less fat, but higher calories. They will also have to take vitamin supplements due to the fact that fats and fat-soluble vitamins are poorly absorbed in them

What are some Useful Resources for Additional Information?

References and Information Sources used for the Article:

Helpful Peer-Reviewed Medical Articles:

Reviewed and Approved by a member of the DoveMed Editorial Board
First uploaded: April 21, 2016
Last updated: May 16, 2018