Duodenal tube test in the diagnosis of biliary atresia

ABSTRACT

Biliary atresia [BA] is a main cause of severe liver damage in infants. Successful surgical treatment is related directly to the early and rapid diagnosis. The aim of this study was to determine specificity, sensitivity and predictive value of duodenal tube test [DTT] in diagnosis of biliary atresia in a series of 20 infants with cholestatic jaundice. The inclusion criteria include a clay coloured stool and a direct bilirubin level > 2mg/dL. The study protocol include thorough history and clinical examination liver function tests complete blood count, abdominal ultrasound. TORCH screen, HIDA scan and percutaneous liver biopsy. A nasoduodenal tube was placed at the distal duodenum and the fluid was collected by gravity every 2 hours for 24 hours. DTT was considered bile positive when yellow biliary fluid was observed. The patients with bile +ve DTT were not explored surgically and cholestatic workup was completed. Laparotomy and ultra-operative cholangiography was indicated for bile -ve DTT patients and porto-enterostomy was done when biliary atresia was identified. The result of the study show that 13 cases were Bile -ve DTT and 7 cases were Bile +ve DTT. Sensitivity, specificity, positive and negative predictive values of DTT vsHIDA scan were 85%, 71%, 80% and 85% respectively. Sensitivity, specificity, positive and negative predictive values of DTT vs percutaneous liver biopsy were 87%, 100%, 100% and 71% respectively. Lastly all of these 4 parameters were 100% on comparing DTT with intra-operative cholangiography