1. Topic Review Biliary atresia Division of gastroenterology Department of pediatric YUMC R3 허윤정

2. Epidemiology Biliary atresia : complete obstruction of bile flow as a result of the destruction or absence of all or a portion of the extrahepatic bile ducts Female > male Occurs in 10,000 to 15,000 live births One third of cases of neonatal cholestatic jaundice 40-50% of all pediatric liver transplants

3. Etiology Cause : unknown Multiple theories of the etiology of biliary atresia 1. perinatal viral infection reovirus, rotavirus 2. genetic factor 3. defects in immune response or autoimmune disorder 4. defects of morphogenesis

4. Classification of the anatomic variants Type I atresia of the common bile duct with patent proximal ducts Type II atresia involves the hepatic duct, with cystically dilated bile ducts at the porta hepatis # type IIa : cystic and common ducts are patents # type IIb : cystic and common ducts are obliterated

5. Classification of the anatomic variants Type III (80% - noncorrectable) obstruction of the common, hepatic, and cystic ducts, without cystically dilated hilar ducts

6. Clinical forms Perinatal type (65-85%) postnatal onset of cholestasis ; normal stool  in 2-4 th weeks Sx develop bile ductular remnants present no associated congenital anomalies Embronic or fetal type(15-35%) early onset of cholestasis ; within the first 3weeks without a jaundice-free period no bile ductular remnants associated congenital anomalies ; cardiovascular defects, polysplenia, malrotaion, situs inversus, bowel atresia

7. Clinical Sx & laboratory finding Normal pregnancy and normal birth weight Postnatal weight gain and development – usually noramal Jaundice hypopigmented or frankly acholic stools dark urine hepatosplenomegaly Conjugated hyperbilirubinemia(>20% of total serum bilirubin) ; usually less than 8mg/dl OT/PT, r-GT elevation

8. Diagnosis Routine liver chemistries jaundice – direct bilirubin >1.0 mg/dl ; pathologic serum lipoprotein–X : (+) >300mg/dl Duodenal bile aspiration yellow pigment of bilirubin – ruled out Abdominal ultrasound : most common used, simple, non-invasive study ; cystic structure # triangular cord (TC) ; a fairly well-circumscribed focal triangular or tubular shaped echogenic density just cranial to the portal vein bifurcation on a transverse longitudinal scan

9. Diagnosis Biliary scintigraphy DISIDA, PIPIDA, HIDA scan ERCP MRCP Percutaneous liver biopsy ; presence of bile plugs in portal triads - highly suggestive of large duct obstruction Visualized percutaneous cholangiogram

10. Treatment Kasai operation ; hepatoportoenterostomy Liver transplantation ; * management of children in whom protoenterostomy dose not successfully restore bile flow * End-stage liver disease * Intractable complications of chronic liver disease

11. Complication Cholangitis (most common, 40-60%) greater risk for the progression to cirrhosis Portal hypertension (2 nd most common, 35-75%) gastrointestinal bleeding Fat-soluble vitamin deficiency Growth failure Pruritis (less common) Tx : UDCA

12. Prognosis Untreated : death within 2 years Kasai operation : 10-year survival rate : 33%

13. Prognosis Prognostic factor 1. age 2. surgical experience 3. recurrent cholangitis 4. site of atresia of the extrahepatic bile duct 5. initial liver biopsy - cirrhosis