Extrahepatic biliary atresia:

Extrahepatic biliary atresia:

• Extrahepatic biliary atresia is obliteration or discontinuity of the bile ducts, usually in the region of the porta (i.e., hepatic or common bile ducts).
• Usually acquired postnatally at approximately 2 – 8 weeks of age.
  • Progressive inflammation of biliary system associated with infections such as CMV, EBV, reovirus, rotavirus.
• Less often congenital and seen with other anomalies such as asplenia or situs inversus.
• Cholestasis leads to jaundice in baby several weeks old. Differential at this age is neonatal hepatitis versus biliary atresia.
• On ultrasound, may see the following:
  • No gallbladder or small, irregular gallbladder.
  • Triangular fibrous (hyper echoic) remnant measuring at least 4 mm in the region of the porta hepatis. This represents the obliterated bile duct.
  • Ultrasound is not very sensitive.
• On nuclear hepatobiliary imaging, see normal prompt homogeneous uptake in the liver (ruling out hepatitis) and NO excretion into the biliary system, even on delayed imaging.
• Patients undergo portoenterostomy (Kasai procedure).
  • If bile duct involved in anastomosis is large, greater chance of success.
  • Greater success if performed before ten weeks of age.
  • Complications include cholangitis, stenosis, and complete failure, which ultimately requires liver transplantation.