Biliary Atresia

Question 1

What is biliary atresia?

Answer 1

Biliary atresia refers to progressive destruction of the extrahepatic biliary system.

Question 2

Overview of biliary atresia

Answer 2

Biliary atresia presents exclusively in the neonatal period with biliary obstruction. It is due to progressive destruction of the extrahepatic biliary system. The cause is idiopathic and may be associated with other congenital malformations.

It is the most common reason for surgical intervention in neonatal jaundice and the most common cause of liver transplantation in children. The incidence is around 1 in 10,000-20,000 live births.

Without surgical intervention to fix the obstruction, the condition is invariably fatal.

Question 3

Biliary atresia is a phenotype that can occurs due to a variety of injuries to the biliary system of the fetus during development or the perinatal period. The cause is idiopathic, but there are some suspected underlying aetiological factors including …

Answer 3

Biliary atresia is a phenotype that can occurs due to a variety of injuries to the biliary system of the fetus during development or the perinatal period. The cause is idiopathic, but there are some suspected underlying aetiological factors including viral, genetic, toxic and immune-mediated.

Question 4

What classification divides the types of biliary atresia into three groups based on anatomy. These can be further subdivided based on proximal and distal anatomical features of the biliary tree.

Answer 4

The Ohi classification divides the types of biliary atresia into three groups based on anatomy. These can be further subdivided based on proximal and distal anatomical features of the biliary tree.

Type 1: common bile duct atresia
Type 2: atresia of hepatic ducts
Type 3: porta hepatis atresia (entry point of vessels and ducts to liver). Most common.

Question 5

Several congenital malformations may associate with biliary atresia including situs inversus, asplenia, intestinal atresia, or imperforate anus to name a few. Newborns with other congenital malformations are more likely to have an embryonic form of biliary atresia and present with jaundice at birth.

Answer 5

Several congenital malformations may associate with biliary atresia including situs inversus, asplenia, intestinal atresia, or imperforate anus to name a few. Newborns with other congenital malformations are more likely to have an embryonic form of biliary atresia and present with jaundice at birth.

Question 6

Biliary atresia presents with …, which can occur any time from birth to …

Answer 6

Biliary atresia presents with jaundice, which can occur any time from birth to 8 weeks.

Question 7

… is a classic ‘surgical’ cause of neonatal jaundice. It is unlikely to appear after 8 weeks.

Answer 7

Biliary atresia is a classic ‘surgical’ cause of neonatal jaundice. It is unlikely to appear after 8 weeks.

Question 8

5 features of biliary atresia

Answer 8

Jaundice (yellow pigmentation of skin and mucous membranes)
Pale stools
Dark urine
Hepatomegaly (may be present)
Associated congenital malformations

Question 9

Presentations of biliary atresia

Answer 9

Embryonic form: jaundice at birth, usually associated with other congenital abnormalities.
Perinatal form: jaundice can develop any time following birth. Unlikely after 8 weeks.

Question 10

How is a definitive diagnosis of biliary atresia made?

Answer 10

A definitive diagnosis of biliary atresia is made by an intraoperative cholangiogram showing biliary obstruction.

Question 11

Biliary atresia is a cause of prolonged jaundice, which is jaundice occurring for >14 days. The key investigation is …

Answer 11

Biliary atresia is a cause of prolonged jaundice, which is jaundice occurring for >14 days. The key investigation is split bilirubin, which looks at both the conjugated and unconjugated components. Conjugated bilirubin (i.e. direct bilirubin) is a marker of biliary obstruction, which is seen in biliary atresia.

Question 12

… bilirubin (i.e. direct bilirubin) is a marker of biliary obstruction, which is seen in biliary atresia.

Answer 12

Conjugated bilirubin (i.e. direct bilirubin) is a marker of biliary obstruction, which is seen in biliary atresia.

Question 13

Investigations in suspected biliary atresia

Answer 13

Investigations confirm conjugated hyperbilirubinaemia and screen for other causes:

Split bilirubin: conjugated bilirubin >17.1 umol/L abnormal
Metabolic screen (inc. TFT, cystic fibrosis): look for inborn errors of metabolism
FBC
LFTs
Others (depending on results and suspicion)