Saturday, March 23, 2013

Biliary Atresia


Biliary Atresia

Persistent conjugated hyperbilirubinemia (greater than 20% of total or 1.5 mg%) should be evaluated.
evaluation includes
history and physical exam,
partial and total bilirubin determination,
type and blood group,
Coomb's test,
reticulocyte cell count
peripheral smear.
Cholestasis means a reduction in bile flow in the liver, which depends on the biliary excretion of the conjugated portion.
 Reduced flow causes retention of biliary lipoproteins that stimulates hypercholesterolemia causing progressive damage to the hepatic cell, fibrosis, cirrhosis and altered liver function tests.
Biliary Atresia (BA) is the most common cause of direct (conjugated) hyperbilirubinemia in the first three months of life.
It is characterized by progressive inflammatory obliteration of the extrahepatic bile ducts, predominance of female patients.
The disease is the result of an acquired inflammatory process with gradual degeneration of the epithelium of the extrahepatic biliary ducts causing luminal obliteration, cholestasis, and biliary cirrhosis.
The timing of the insult after birth suggests a infectious etiology obtained transplacentally.
Almost 20% of patients have associated anomalies such as:
polysplenia, malrotation, situs inversus, preduodenal portal vein and absent inferior vena cava.
Histopathology
progressive destruction,
scar formation, and chronic granulation tissue of bile ducts.
Physiologic jaundice of the newborn is a common, benign, and self-limiting condition.
In BA the patient develops jaundice by the second week of life.
The baby looks active, not acutely ill and progressively develops acholic stools, choluria and hepatomegaly.
Non-surgical causes of cholestasis present as a sick, low weight infant who is jaundiced since birth.
The evaluation of the cholestatic infant
Sreen for perinatal infectious (TORCH titers, hepatitis profile),
metabolic (alpha-1-antitrypsin levels),
systemic and hereditary causes.
Total bilirubin in BA babies is around 6-10 mg%, with 50-80% conjugated.
Liver function tests are nonspecific.
Lipoprotein-X levels greater than 300 mg
Gamma Glutamyl Transpeptidase (GGT) above 200 units
 The presence of the yellow bilirubin pigment in the aspirate of duodenal content excludes the diagnosis of BA.
Ultrasound study of the abdomen = imaging study done to evaluate the presence of a gallbladder, identify intra or extrahepatic bile ducts dilatation, and liver parenchyma echogenicity.
The postprandial contraction of the gallbladder eliminates the possibility of BA
Nuclear studies of bilio-enteric excretion (DISIDA) after pre-stimulation with phenobarbital for 3-5 days is the diagnostic imaging test of choice.
The presence of the radio-isotope in the GI tract excludes the diagnosis of BA.
Percutaneous liver biopsy should be the next diagnostic step.
The mini-laparotomy is the final diagnostic alternative.
Those infant with radiographic evidence of patent extrahepatic biliary tract has no BA.
Medical management of BA in our hospital is
Antibiotics Cefotaxime and ampicillin for 14 days parenterally
Vitamin A,D,(once a month and K( once a week) injections
Vitamin E orally daily
Kasai procedure consists =
removing the obliterated extrahepatic biliary system,
anastomosing the most proximal part to a bowel segment.
patients may develop portal hypertension = manifest esophageal varices, hypersplenism, and ascites.
Hepatic transplantation if progressive liver failure

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