Biliary Atresia FAQs
What is Biliary Atresia?
Biliary Atresia is a liver disease which affects infants. The ducts which drain bile from the liver are missing due to a developmental abnormality or destroyed by an inflammatory process which starts soon after birth. The latter of these is considered the most common form of the disease. The bile which is trapped in the liver then causes damage to it.
The incidence of biliary atresia varies around the world but a commonly quoted figure is around 1 in every 15 000 births. It is believed to be more common in girls than in boys, and more prevalent in oriental races.
What are the signs and symptoms of Biliary Atresia?
Many newborn babies have jaundice, but in babies with biliary atresia and other liver diseases the jaundice continues and often worsens beyond two weeks of age. The stools will be pale in colour rather than the usual mustard yellow, and urine will be yellow in colour when it should be completely clear. The baby may be irritable and struggle to put on weight.
How is biliary atresia diagnosed?
If a baby is jaundiced beyond two weeks of age, they should be referred for a split bilirubin test. Bilirubin is produced when red blood cells break down, and is the pigment which causes jaundice. Before it has been processed by the liver bilirubin is called unconjugated or indirect; afterwards it has been processed it is conjugated or direct. A high level of direct bilirubin in the babyís blood shows there may be a problem with the flow of bile from the liver. When doctors examine the baby, they may find that their liver is enlarged and hard, and the spleen is enlarged too.
Other blood tests will be taken. These will help to indicate whether the jaundice is caused by a liver problem. If the blood tests show that the liver may be involved, further testing will take place to try and establish whether the diagnosis is biliary atresia or another liver disease.
A baby suspected of having biliary atresia may have an ultrasound examination, a HIDA scan (dye is injected to investigate drainage of bile), and a liver biopsy. Although these tests give a strong indication, none of them are completely conclusive, and an intra-operative cholangiogram is considered the standard in diagnosis. This is where the flow of bile is tested with dye during surgery, usually before carrying out the Kasai procedure (see below).
What is the treatment for biliary atresia?
The only treatment for babies with biliary atresia is the Kasai procedure. This is a surgical procedure where a section of the babyís intestinal tract is removed and used to make a new bile duct. If there is no duct at all left outside the liver, part of the liver will be cut away until the surgeon finds evidence of tiny bile ducts, and the intestine will be attached there. Some babies have bile duct remnants outside the liver, and for these variations of the Kasai may be possible.
The Kasai operation establishes bile flow from the liver in around 40-60% of babies. The signs that this has happened are a clearance of jaundice, darker stools, and paler urine. It is important that the Kasai operation is done quickly in babies with biliary atresia, before the damage caused to the liver is too extensive. It has also been shown that the experience of the surgeon influences the success of the operation.
What happens after the surgery?
After the Kasai procedure, babies may go to an intensive care or high dependency unit, usually for a few days at the most if the post operative recovery is smooth. There will then usually be a further week in medium care before the baby is discharged from hospital. Once at home, babies have regular blood tests to monitor whether the operation has been successful. They will have medications to take, which vary from one centre to another. It will be important to keep track of their weight and they will probably have a dietician, as children with liver disease often have trouble putting on weight.
What is the outlook if bile flow isnít restored?
If the Kasai operation does not restore bile flow, then the damage to the liver will continue. The baby will usually need a liver transplant between about 6 and 12 months old. Liver transplant is a very successful therapy for biliary atresia.
What is the outlook if bile flow is restored?
If bile flow is restored, then there is the possibility of the baby going on to have a problem free life for many years after the Kasai. In some cases, as many as 30 or 40 years, but so far these are proving the rarity. At the other end of the scale, sometimes despite the re-establishment of bile flow, heavy damage to the liver or post Kasai complications may result in an early transplant still being needed.
Most patients with biliary atresia will require a liver transplant at some stage, but for those with a working Kasai, if and when that might happen depends on many different factors.
The biggest risk in the immediate months following the Kasai procedure is ascending cholangitis. This is a bacterial infection of the bile ducts inside the liver, caused by the intestine being attached directly to the liver. Cholangitis can rarely be confirmed except by biopsy, so most suspected cases are treated aggressively with IV antibiotics before the infection can damage the liver. Cholangitis should be suspected if there is a fever, either unexplained or accompanied by signs of new or worsening jaundice. The risk of cholangitis is known to decrease significantly after the first year post Kasai, but it can occur at any age.
At the time of Kasai, there is usually already damage to the liver. Afterwards, this damage appears to continue, although at an unpredictable rate. The consequence of this is that patients with biliary atresia are susceptible to complications of chronic liver disease, such as ascites, itching and portal hypertension, as well as other rarer side effects. Patients are monitored for the development of these conditions. If complications of liver disease become uncontrollable despite treatment, then transplantation will be considered.
What is the long term outlook?
Overall survival and quality of life are good for the majority of patients with biliary atresia. It is still a life threatening disorder, with no cure, as transplantation still results in a lifetime of medical management. Advances continue to be made in the medical field which will improve the outlook still further.