Biliary atresia

Background

Intraoperative view of complete extrahepatic biliary atresia.

• Rare, but leading indication for liver transplantation in children
• Exact etiology unclear, but inflammation leads to destruction of intra/extrahepatic bile ducts
• Prognosis significantly improved by early diagnosis
• Two forms:
  • Peri/postnatal (90% of cases), possibly related to infection
  • Fetal/embryonic (10%)
    • Often with other associated malformations (e.g congenital heart disease, polysplenia or asplenia, malrotation, situs inversus, portal vein or hepatic artery malformations)

Gallbladder disease types

Gallbladder anatomy (overview).

Gallbladder anatomy

• Symptomatic cholelithiasis (biliary colic)
• Choledocholithiasis
• Acute calculous cholecystitis
• Ascending cholangitis
• Acalculous cholecystitis
• Biliary atresia
• Cholestasis of pregnancy

Clinical Features

• Presentation often subtle
• Neonatal jaundice
  • High index of suspicion for jaundice that persists beyond 1st week of life or includes conjugated hyperbilirubinemia
• Hepatomegaly
• Acholic stools
• Dark urine
• Late findings: failure to thrive, ascites, splenomegaly

Differential Diagnosis

Indirect (Unconjugated) Hyperbilirubinemia

More common causes are listed first, followed by less common causes

• Breast milk jaundice
  • Due to substances in milk that inhibits glucuronyl transferase. It may start as early as 3rd day and reaches peak by 3rd week of life. It is unlikely to cause kernicterus
• Breast feeding jaundice
  • Patient does not receive adequate oral intake which then causes reduced bowel movement/bilirubin excretion. Best diagnosed by looking for signs of dehydration and comparing weight to birth weight.
• Blood group incompatibility: ABO, Rh factor, minor antigens
• Diabetic mother/gestational diabetes
• Internal hemorrhage
• Physiologic jaundice
• Polycythemia
• Sepsis
• Hemoglobinopathies: thalassemia
• Red blood cell enzyme defects: G6PD Deficiency, pyruvate kinase
• Red blood cell membrane disorders: spherocytosis, ovalocytosis
• Hypothyroidism
• Immune thrombocytopenic purpura
• Mutations of glucuronyl transferase (i.e., Crigler-Najjar syndrome, Gilbert syndrome)

Direct (Conjugated) Hyperbilirubinemia

Conjugated bilirubinemia implies a hepatic or post hepatic cause. More common causes are listed first.

• Hyperalimentation cholestasis
• Neonatal hepatitis
• Cytomegalovirus infection
• Sepsis
• TORCH infection (toxoplasma, other/syphilis, rubella, CMV, HSV)
• Biliary atresia
• Cystic fibrosis
• Hepatic infarction
• Inborn errors of metabolism (e.g., galactosemia, tyrosinosis)

Evaluation

Persistent neonatal cholestasis and biopsy-proven biliary atresia in a 1.5-month-old boy. US shows the triangular cord sign (arrow in a) and increased diameter of the hepatic artery (27 mm, arrow in b)

• Evaluate for other causes of neonatal jaundice, liver failure
• Assess for complications of liver disease (e.g. coagulopathy)
• RUQ US to screen for other abnormalities (though cannot definitively diagnose biliary atresia)
• Definitive diagnosis made by biopsy or surgical pathology

Management

• Surgery
  • Kasai procedure or liver transplant for those who fail kasai
• Coagulopathy (if present) responds to vitamin K supplementation

Disposition

• Admit

See Also

• Neonatal jaundice

References

https://pedemmorsels.com/biliary-atresia/