Cholestasis, Extrahepatic: Biliary Atresia

Key Features

Essentials of Diagnosis

• Extrahepatic neonatal cholestasis is characterized by

  • Complete and persistent cholestasis (acholic stools) in the first 3 months of life

  • Lack of patency of the extrahepatic biliary tree proved by intraoperative, percutaneous, or endoscopic cholangiography

  • Firm to hard hepatomegaly

  • Typical features on histologic examination of liver biopsy tissue

General Considerations

• Progressive fibroinflammatory obliteration of the lumen of all, or part of, the extrahepatic biliary tree presenting within the first 3 months of life

• Three types

  • Isolated (84% of cases): meconium and initial stools are usually normal in color, suggesting early patency of the ducts

  • BA with at least one malformation but without laterality defects (6%; cardiovascular, gastrointestinal, or genitourinary defects): bile duct presumably did not develop normally and is associated with other nonhepatic congenital anomalies

  • BA splenic malformation syndrome associated with laterality defects and polysplenia or asplenia (4–10%): supports an embryonic origin of BA

Demographics

• Incidence highest in Asians, African Americans, and preterm infants

  • 1:6600 in Taiwan

  • 1:18,000 in Europe

  • 1:12,000 in United States

• Slight female predominance

Clinical Findings

Symptoms and Signs

• Jaundice may be noted in the newborn period or develop by age 2–3 weeks

• Urine stains the diaper

• Stools are often pale yellow, gray, or acholic

• Firm hepatomegaly is common

• By age 6 months, the growth curve reveals poor weight gain

• Symptoms of portal hypertension (splenomegaly, ascites, variceal bleeding) may develop in the first year of life

• Pruritus, digital clubbing, failure to thrive, bone fractures, and bleeding complications may also occur later in childhood

Differential Diagnosis

• Bile duct paucity

• Metabolic liver disease (particularly α₁-antitrypsin deficiency)

• Choledochal cyst

• Intrinsic bile duct obstruction (stones, bile plugs)

Diagnosis

Laboratory Findings

• No single laboratory test consistently differentiates BA from other causes of complete obstructive jaundice

• Aminotransferases are only moderately elevated in BA

• Serum albumin and blood clotting factors are normal early in the disease

Imaging

• Ultrasonography

  • Should be performed to exclude the presence of choledochal cyst and identify intra-abdominal anomalies

  • A triangular cord sign in the hepatic porta suggests BA

Diagnostic Procedure

• Intraoperative cholangiogram should be performed as soon as possible if BA cannot be excluded by diagnostic evaluation and percutaneous liver biopsy

• Liver biopsy specimens (particularly if obtained after age 6 weeks) can differentiate intrahepatic causes of cholestasis from BA in over 90% of cases

Treatment

• Hepatoportoenterostomy (Kasai procedure)

  • Standard therapeutic procedure

  • Should not be undertaken in infants older than age 4 months because the likelihood of bile drainage at this age is very low

• Portocholecystostomy (gallbladder Kasai ...