Biliary atresia (Part two)

Clinic:

1. Skin and sclera jaundice. In newborns, jaundice as a result of liver immaturity is common, but it usually disappears in the first week to ten days of life. A baby with biliary atresia may be normal at birth and develops jaundice two to 4 weeks after birth.
2. Dark urine.
3. Acholic feces because bile is not excreted into the intestine. Also, we may have abdominal bloating as a result of an enlarged liver.
4. Weight loss and irritability. They develop when the level of jaundice increases.

Extrahepatic biliary atresia is divided into three types. Type I: atresia of the common bile duct. Type II: atresia of the common hepatic duct. Type III: atresia of the right and left hepatic ducts.

Biliary atresia in 10-20% of patients is associated with other anomalies such as polysplenia, bilateral bilobed lungs, intestinal malrotation, situs inversus, continuation of the azygos vein into the Inferior Vena Cava.

Examinations that help in making the diagnosis:

1. Direct abdominal radiography may show an enlarged liver or spleen.
2. Blood laboratory examinations are done to see if there is damage to liver function.
3. Ultrasound is used to exclude other causes of obstructive jaundice such as choledochal cyst, obstructive mass, or gallstones in the gallbladder.

The gallbladder is small or absent in many patients with biliary tract atresia, however, in 20% of patients, a normal gallbladder may be seen.

As a characteristic sonographic finding of biliary atresia, a triangular echogenic focus representing the atretic biliary tree has been described. This echogenic focus along the anterior wall of the right portal vein with a thickness greater than 4 mm, is considered to be a more reliable finding for the diagnosis of biliary atresia than the size of the gallbladder. Such a finding can also be seen in MR cholangiography.

In diagnosis, hepatobiliary scintigraphy is also of great help. A tracer dose that concentrates in the liver and is excreted through the biliary tract is given. If excretion is detected in the gastrointestinal tract then the diagnosis of biliary atresia is excluded. In patients with severe hepatitis, a 24-hour follow-up after tracer injection is needed to be sure of the diagnosis.

CT can be used to demonstrate associated abnormalities of biliary atresia. It can also be used to assist patients who develop cholangitis, dilation of the biliary tract, bilomas, or intrahepatic stones after surgical correction.

Also, CT assesses the development of hepatic cirrhosis, varices, splenomegaly, and ascites and provides assistance for pre-transplant assessment in these patients.

The final diagnosis is made with liver biopsy and intra-operative cholangiography.

Case:

A 1-month-old female infant presents with pronounced jaundice in the skin and sclera, dermatitis, with hypocholic feces, afebrile. With total bilirubin 8.8 mg/dl, direct bilirubin 4.8 mg/dl ALP 397 U/L, AST 183 U/L, ALT 173 U/L, GGT 1397 U/L. On ultrasound, the liver size is 72 mm, the gallbladder and common bile duct are not visualized. The spleen is 62 mm, an accessory spleen is noted in the hilum with a diameter of 12 mm. Lung radiography: negative lungs.