This is a condition of uncertain cause where part, or all, of the extrahepatic 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.
- There are approximately fifty cases in the UK each year (1/15,000 births).
- There is a wide variation in incidence throughout the world - eg, the incidence is 1 in 5,000 in Taiwan.
- Approximately 20% 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.
- Biliary atresia presents shortly after birth, with persistent jaundice, pale stools and dark urine in term infants with normal birth weights. All term infants who remain jaundiced after 14 days (and preterm infants after 21 days) should be investigated for liver disease, initially with simple measurement of the conjugated fraction of bilirubin.
- Normal meconium is passed initially and the stools may be bile-coloured for a short period afterwards, but pale stools are the rule.
- Splenomegaly is not usually a feature unless presentation is late (aged more than 3 months) and it is thus a sign of portal hypertension.
- Failure to thrive is a result of poor absorption of long-chain fats and the catabolic state.
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).
- LFTs are abnormal with a conjugated hyperbilirubinaemia. Gamma-glutamyltransferase (GGT) is usually higher in biliary atresia than in other causes of neonatal cholestasis. Serum cholesterol might be raised but triglycerides are within the normal range.
- Ultrasound and hepatobiliary scintigraphy (technetium-99m) can be used to help differentiate atresia from neonatal hepatitis, intrahepatic biliary hypoplasia and extrahepatic obstructive lesions.
- Liver histology (obtained by percutaneous biopsy) is the usual diagnostic method of choice.
- Endoscopic retrograde cholangiopancreatography to visualise the biliary tract is occasionally needed when the diagnosis is unclear, but it is technically difficult in infants and use is confined to large centres.
- Other causes of obstructive jaundice - choledochal cyst, cholelithiasis and spontaneous perforation of the bile duct can all occur in the neonatal period.
- Cystic fibrosis.
- Lipid storage disorders.
- Idiopathic neonatal hepatitis.
- Congenital infections.
- Alpha-1-antitrypsin (A1AT) deficiency.
Surgery (portoenterostomy and liver transplantation) are the mainstay of treatment.
Medical management includes:
- The use of antibiotics to prevent cholangitis.
- Ursodeoxycholic acid to encourage bile flow.
- Fat-soluble vitamin supplementation and nutritional support.
The use of corticosteroids to improve biliary drainage is controversial and not yet fully understood.
- 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.
- Portoenterostomy remains as the first-line operative treatment in biliary atresia while liver transplantation serves as a salvage treatment when portoenterostomy fails or liver function gradually deteriorates after initially successful establishment of bile flow.
- Early liver transplantation appears to be beneficial in cases with an available liver for transplantation.
- Ascending cholangitis can develop in the first few months after surgery, with recurrence of jaundice, acholic stool and abdominal pain. Sometimes sepsis is severe and requires resuscitation and intensive care.
- Recurrent or late cholangitis might suggest an obstruction of the Roux-en-Y loop as it passes through the mesocolon. Bile lakes can develop in the liver at any time after surgery and could be a source of recurrent infection.
- Cirrhosis, portal hypertension and liver failure.
- Hepatocellular carcinoma.
- Osteomalacia or biliary rickets.
- 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 led to improved management and outcome of biliary atresia.
- Survival is now over 90% in the UK.
- 60% of children will achieve biliary drainage after Kasai portoenterostomy and will have serum bilirubin within the normal range within six months. 80% of those children will reach adolescence with a good quality of life without needing liver transplantation.
- However, those surviving to adulthood with their native liver often develop secondary biliary disease, including cholangitis and portal hypertension.
- If liver transplantation is needed, it provides a 90% chance of achieving a normal life.
Further reading and references
; Biliary atresia - a new derivative method? Bratisl Lek Listy. 2014115(1):49-53.
; Current management of biliary atresia. Arch Dis Child. 2007 Dec92(12):1132-5. Epub 2007 Sep 18.
; Biliary atresia: clinical aspects. Semin Pediatr Surg. 2012 Aug21(3):175-84. doi: 10.1053/j.sempedsurg.2012.05.010.
; Biliary atresia. Lancet. 2009 Nov 14374(9702):1704-13.
; Aetiology of biliary atresia: what is actually known? Orphanet J Rare Dis. 2013 Aug 298:128. doi: 10.1186/1750-1172-8-128.
; Biliary atresia: a multidisciplinary approach to diagnosis and management. Arch Pathol Lab Med. 2012 Jul136(7):746-60. doi: 10.5858/arpa.2011-0623-RA.
; Long-term outcome of children with biliary atresia who were not transplanted after the Kasai operation: >20-year experience at a children's hospital. J Pediatr Gastroenterol Nutr. 2009 Apr48(4):443-50.
; Surgery of biliary atresia. Scand J Surg. 2011100(1):49-53.
; What is the Optimal Timing of Liver Transplantation for Children with Biliary Atresia? A Markov Model Simulation Analysis. J Pediatr Gastroenterol Nutr. 2014 May 11.
; The long-term outcome of the Kasai operation in patients with biliary atresia: a systematic review. Neth J Med. 2013 May71(4):170-3.
; Biliary atresia and survival into adulthood without transplantation: a collaborative multicentre clinic review. Liver Int. 2012 Mar32(3):510-8. doi: 10.1111/j.1478-3231.2011.02668.x. Epub 2011 Nov 9.