Biliary Atresia

DESCRIPTION

Biliary atresia (BA) is a congenital disease characterized by fibrosis, obstruction, and obliteration of the biliary system that is universally fatal without intervention.

EPIDEMIOLOGY

• BA accounts for approximately 30% of cases of neonatal cholestasis.
• BA is the most common cause of persistent cholestasis in infants and children and the most frequent indication for pediatric liver transplantation.
• The disease affects 1:8,000 to 1:18,000 live births.

RISK-FACTORS

PATHOPHYSIOLOGY

• Biliary obstruction begins at, or near, the time of birth and progresses throughout early infancy, leading to damage and ultimately scarring of liver parenchyma.
• Approximately 20% of biliary patients have at least one other major congenital anomaly (i.e., embryonal form) including splenic malformation, interrupted inferior vena cava, midline liver, situs inversus, preduodenal portal vein, and intestinal malrotation.
• More common form is the perinatal form that is not associated with malformations.

ETIOLOGY

Etiology is not completely defined, but many different pathogenic mechanisms have been proposed, including the following:

• Perinatal infection of the liver and biliary tract with potential organisms including cytomegalovirus, rotavirus, and reovirus
• Immune dysregulation
• Defective morphogenesis
• Environmental toxin exposure
• Vascular insufficiency