Biliary atresia

Biliary atresia (BA) is a congenital biliary disorder, which is characterised by an absence or severe deficiency of the extra-hepatic biliary tree. It is one of the most common causes of neonatal cholestasis, often causing cirrhosis immediately and leading to death and accounts for over half of children who undergo liver transplantation. 

Epidemiology

It is thought to affect 1 in 10,000 - 15,000 newborn infants. There is a recognised male predilection.

Clinical presentation

 It precipitates within the first 3 months of life. Infants with biliary atresia may appear normal and healthy at birth. Most often, symptoms develop between two weeks to two months of life, and may include :

• jaundice
• dark yellow or brown urine
• pale or clay-colored (acholic) stools
• hepatomegaly

Radiographic features

Prompt diagnosis ensures early treatment and results in improved prognosis.

Abdominal ultrasound

• echogenic triangular cord sign
• larger hepatic arterial calibre ²

Nuclear medicine (hepatobiliary (HIDA) scan)

Tc-⁹⁹m diosgenin (DISIDA) and mebrofenin (BRIDA) have highest hepatic extraction rate and shortest transit time of hepatobiliary radiotracers. Cases of biliary atresia typically demonstrate relatively good hepatic uptake with no evidence of excretion into the bowel at 24 hours. Pretreatment with phenobarbital (5 mg/kg/day for 5 days) to increase biliary secretion by stimulating hepatic enzymes is freqeuently helpful to minimize the possibility of a false-positive study in a patient with a patent biliary system but poor excretion.

Complications

portal hypertension ³

Treatment and prognosis

Management options include

• Kasai portoenterostomy
• liver transplantation

More content required for prognosis

Differential diagnosis

General differential considerations include

• neonatal hepatitis
• Alagille syndrome
• Caroli disease
• bile plug syndrome
• lipid storage disorders