BILIARY HYPOPLASIA IN CHILDREN

Biliary hypoplasia is a rare cause of persistent neonatal conjugated hyperbilirubinemia. Pathologically, affected children have absent or reduced number of bile ductules with normal distribution of branches of the portal vein and hepatic artery within the liver parenchyma. Biliary hypoplasia is also identified as paucity of interlobular bile ducts (PILBD).

Two types of PILBD are recognized:
1) syndromic (arteriohepatic dysplasia or Alagille's syndrome) with characteristic extrahepatic abnormalities (fascial appearance, pulmonic artery stenosis, vertebral anomalies, embryotoxon and delayed weight-height development), and

2) non-syndromic biliary hypoplasia. Biliary hypoplasia is clinically indistinguishable from biliary atresia and can sometimes be confused. A definitive diagnosis is difficult to make in early infancy. Differentiation between biliary atresia, hypoplasia and neonatal hepatitis continues to require direct visualization of the biliary ducts. This mean laparoscopic or open intra-operative cholangiography and liver biopsy. The cholangiogram will show diminutive intra- and extra-hepatic biliary tree.

Attempts to establish biliary flow by means of hepatic porto-enterostomy (Kasai procedures) in children with PILBD have been unsuccessful and contraindicated. Management is conservative and include predigested formulas, ursodeoxycholic acids (10 mg/kg/day), phenobarbital and A,D,K,E vitamin replacement. Non-syndromic PILBD have better long-term prognosis. Children with syndromic PILBD identified in infancy because of cholestasis have a 50% probability of long-term survival without liver transplantation.