Biliary Atresia

This is a condition of uncertain cause where part, or all, of the extra-hepatic bile ducts are obliterated by inflammation and subsequent fibrosis, leading to biliary obstruction and jaundice. It is fatal if untreated. A viral aetiology has been proposed although the association with other congenital anomalies in some cases suggests a possible developmental abnormality.

• Approximately fifty cases in the UK each year (1/15,000 births).¹
• More common in females than males.²
• Incidence highest in Asian populations.²
• Up to a quarter have co-existing congenital anomalies most commonly involving the heart, abdomen and genitourinary tract. There may be associated situs inversus or polysplenia/asplenia with or without other congenital anomalies.²

• Infants are typically full term and present in the first few weeks of life with fluctuating but progressive jaundice, dark urine, and pale stools.
• Normal meconium is passed initially and the stools may be bile-coloured for a short period afterwards, but pale stools are the rule.
• There may be firm hepatomegaly and occasional splenomegaly.

This is according to the site of atresia in the extrahepatic biliary system:

• Type I: common bile duct atresia with patent proximal ducts
• Type II: common hepatic duct atresia with cystic structures in the porta hepatis
• Type III: right and left hepatic duct atresia to the level of the porta hepatis (most common)

• LFT's are abnormal with a conjugated hyperbilirubinaemia.
• Ultrasound and hepatobiliary scintigraphy (Tc-99m) can be used to help differentiate atresia from neonatal hepatitis, intrahepatic biliary hypoplasia and extrahepatic obstructive lesions.
• Percutaneous liver biopsy can also be used to evaluate neonatal cholestasis.²
• Intraoperative cholangiography can demonstrate anatomy and duct patency, establishing a diagnosis of biliary atresia.²

• Other causes of obstructive jaundice - choledochal cyst, cholelithiasis and spontaneous perforation of the bile duct can all occur in the neonatal period
• Idiopathic neonatal hepatitis
• Congenital infections
• Alpha 1-anti-trypsin deficiency

• Provided there is no cirrhosis and the patient presents early, the primary treatment for biliary atresia is the Kasai portoenterostomy or one of its variants.
• In the unmodified operation the atretic extrahepatic tissue is removed and a Roux-en-Y jejunal loop anastomosed to the hepatic hilum. It may restore bile flow and clear jaundice.
• Best results are achieved if surgery is performed before 8 weeks of age.¹
• Cholangitis is a common complication of surgery.²
• If surgery fails, or the patient presents after 120 days, the patient should be considered for liver transplantation.
• Medical management includes the use of antibiotics to prevent cholangitis, ursodeoxycholic acid to encourage bile flow, fat soluble vitamin supplementation and nutritional support.¹

• Cirrhosis and portal hypertension
• Hepatocellular carcinoma
• Osteomalacia or biliary rickets³

• Survival without any treatment is approximately 18 months.
• Improved education leading to early referral and diagnosis to allow surgery before 8 weeks in specialised centres has lead to improved management and outcome of biliary atresia.¹
• Survival is now over 90% in the UK.¹
• Over half of infants undergoing portoenterostomy will clear the jaundice and have a greater than 80% chance of a good quality of life, reaching adolescence without transplantation.¹
• If liver transplantation is needed, it provides a 90% chance of achieving a normal life.¹
• Serum bilirubin level at 3 months after the Kasai operation can be used to predict outcome and long-term survival. Efforts to improve bile flow after the operation may lead to improved outcome.^4,5

Research at the Institute of Child Health looked at the possibility of screening for biliary atresia using the bloodspot sample but the techniques used had high false positive rates. The National Screening Committee have stated that screening for biliary atresia should not currently be used.⁶