DIAGNOSTIC ANCILLARY PROCEDURES AND FINDINGS RICCEL, VON AT EMAN

ULTRASOUND Ultrasound tests can show whether the liver or bile ducts are enlarged and whether tumors or cysts are blocking the flow of bile. Initial test of choice Assess any abnormalities of the heptabiliary tract It cannot be used to make a diagnosis of biliary atresia, but it does help rule out other common causes of jaundice Produces an image on a computer screen using sound waves.

Hepatobiliary scintigraphy Demonstrates bile duct patency using radionucleotide (DISIDA) A new diagnostic approach to biliary atresia with emphasis on the ultrasonographic triangular cord sign Hepatobiliary imaging, using technetium-labeled diisopropyl iminodiacetic acid (DISIDA) nuclear scintiscan, is useful in evaluating infants with suspected biliary atresia. Unequivocal evidence of intestinal excretion of radiolabel confirms patency of the extrahepatic biliary system. Rules out bile duct obstruction and has a specificity of 50 to 75% for the diagnosis of atresia, despite a high sensitivity (95%). This is because cholestatic parenchymal diseases may have the same pattern Two cautionary notes are required. First, reliability of the scintiscan is diminished at very high conjugated bilirubin levels (>20 mg/dL). Second, the test has been associated with a 10% rate of false-positive or false-negative diagnostic errors.

Triangular cord sign Sensitivity 100% and Specificity 100% Liver hilum appears hyperechogenic

95-day-old female infant with neonatal hepatitis 95-day-old female infant with neonatal hepatitis. Sonogram shows normal gallbladder. Gallbladder is 3.1 cm long. (left) 64-day-old female infant with biliary atresia. Sonogram shows abnormal gallbladder (arrows). Gallbladder is 1.0 cm long. (right)

LIVER SCANS HEPATOBILIARY IMINODIACETIC ACID (HIDA) SCANNING Traces the path of bile in the body and can show whether bile flow is blocked Infants with biliary atresia usually have normal uptake of the isotope but absent excretion into the biliary system and small intestine Enhance isotope excretion with 5 days of pretreatment with phenobarbital Special types of x rays that use substances that can be detected by cameras to create an image of the liver and bile ducts.

LIVER BIOPSY It can help rule out other liver problems, such as hepatitis Recommended before surgical procedure Portal tract edema, fibrosis, inflammation, intracellular and canalicular cholestasis, proliferation of bile ductules The infant is sedated and a needle is passed through the skin and then quickly in and out of the liver. A small piece of liver, about the size of a pencil lead, is obtained for examination using a microscope. It can help rule out other liver problems, such as hepatitis

OPERATIVE CHOANGIOGRAPHY Gold standard for the diagnosis of BA If intact extrahepatic biliary system is not visualized,then extrahepatic biliary atresia is evident. If an intact biliary tree is visible, then perform an intraoperative cholangiogram Cannulate the bile duct through transverse abdominal incision and inject contrast to determine if the biliary ducts are patent At the porta hepatis there are microscopic bile ductules that have proliferated which communicate with the intrahepatic system

Correctable lesion – 20% fibrosis of the distal biliary tree, however proximal biliary tree and intrahepatic bile ducts are patent Excise fibrotic area and direct drainage to bowel Non – correctable – 80% Fibrosis to the level of the porta hepatis Kasai procedure

TREATMENT

The current management of BA patients involves two steps: Kasai operation (in the neonatal period), which aims to restore bile flow. Fig. 1: KASAI procedure SEE ATTACHED FILE FOR THE DETAILS REGARDING THIS MATTER Fig. 2: Hepatoporto-cholecystostomy

Liver transplantation in those where the Kasai operation has failed in its primary aim or complications of biliary cirrhosis have supervened

REFERENCES Sabiston Textbook of Surgery 17th Edition Harrison’s Principles of Internal Medicine 17th Edition http://digestive.niddk.nih.gov/ddiseases/pubs/atresia/BiliaryAtresia.pdf