Biliary Atresia

  • Etiology: two types:
    — Perinatal (Acquired) is 80% of cases and is due to inflammation causing destruction of fully formed biliary ducts
    — Embryonic (Fetal) is 20% of cases
  • Imaging: absence of biliary tree
  • US: gallbladder is small to absent (<15-19 mm in length), triangular cord sign is obliterated fibrous ductal remnant with thickening near bifurcation of portal vein that is positive if > 3-4 mm but is difficult to identify, nonvisualization of common bile duct, hypertrophied hepatic artery
  • HIDA scan: pretreat with phenobarbital for 1 week to optimize liver uptake, decreased uptake of radiotracer in liver, no excretion of radiotracer into biliary tree or bowel
  • DDX: neonatal hepatitis
  • Treatment: Kasai hepatic portoenterostomy – resect biliary remnant and creat Roux-en-Y intestinal anastomosis within 60 days to prevent liver fibrosis and failure
  • Clinical: most common cause of neonatal cholestasis, clinical triad is jaundice / acholic stool / dark urine, Embryonic (Fetal) type associated with heterotaxy (50%) and thus polysplenia / asplenia and malrotation, preduodenal portal vein (60%), interrupted inferior vena cava (40%), cardiac anomalies (50%)

Radiology Cases of Biliary Atresia

hepatobiliary scintigraphy scan of biliary atresia
Immediate image (upper left) from a hepatobiliary scintigraphy exam performed after pre-treatment with phenobarbital shows good uptake of radiotracer in the liver with the 24 hour delayed image (upper right) showing no excretion of radiotracer into the bowel. Transverse US of the liver (lower left) shows the presence of a gallbladder. AP image of an intraoperative cholangiogram shows a dilated gallbladder (with some contrast extravasation outside of the gallbladder) and minimal visualization of the intrahepatic biliary tree and no visualization of the extrahepatic biliary tree.