Biliary atresia

Overview

•Prolonged jaundice - persisting beyond 14 days (term) or 21 days (preterm); always conjugated (direct) hyperbilirubinaemia

•Pale/acholic stools - chalky white or putty-coloured due to absent bile pigment

•Dark urine - conjugated bilirubin is water-soluble and spills into urine

•Hepatomegaly - firm, enlarged liver due to cholestasis and early fibrosis

•Splenomegaly - develops as portal hypertension progresses

•Poor weight gain/failure to thrive - fat malabsorption due to absent bile delivery

🚨

Pale stools + dark urine in a jaundiced neonate = biliary atresia until proven otherwise. Any conjugated hyperbilirubinaemia at any age requires urgent investigation.

Investigations

🥇 First-line

•Serum bilirubin (conjugated + unconjugated) - raised conjugated fraction confirms cholestasis

•LFTs (ALT, AST, GGT, ALP) - GGT disproportionately elevated; raised transaminases suggest hepatocellular damage

•Neonatal heel prick test - excludes cystic fibrosis, hypothyroidism, metabolic disorders

•Serum alpha-1 antitrypsin level and phenotype - excludes alpha-1 antitrypsin deficiency

•Abdominal ultrasound - triangular cord sign (echogenic fibrous remnant at porta hepatis); absent or small gallbladder; CBD not visualised

🥈 Second-line

•Hepatobiliary scintigraphy (HIDA/DISIDA scan) - liver takes up isotope but absent/reduced excretion into bowel confirms biliary obstruction

•Liver biopsy - bile duct proliferation, portal fibrosis, bile plugging; differentiates from intrahepatic causes

🏆 Gold standard

•Operative cholangiography (intraoperative) - contrast injected into biliary tree confirms diagnosis with certainty

Management

🎯

Kasai portoenterostomy = first-line treatment. Liver transplantation = salvage/second-line. Ursodeoxycholic acid and co-trimoxazole = adjuncts post-surgery only - never standalone first-line management.

Complications

•Ascending cholangitis - most common serious early post-Kasai complication; recurrence of jaundice, fever, acholic stools; treated with IV antibiotics

•Portal hypertension - oesophageal varices and risk of haemorrhage as fibrosis progresses

•Cirrhosis and liver failure - majority eventually require transplantation even after initially successful Kasai

•Fat-soluble vitamin deficiency (A, D, E, K) - vitamin K deficiency causes coagulopathy