[Duodenal tube test and hepatic ultrasound in extrahepatic biliary atresia diagnosis: A four-case series].

Liver and biliary tree scintigraphy and magnetic resonance cholangiography (MRC) have taken the place of the duodenal tube test (DTT) in the study of cholestatic jaundice due to extrahepatic biliary atresia (EBA). The usefulness of DTT associated with abdominal ultrasound (AUS) in the diagnosis of EBA was demonstrated in 4 patients presenting with cholestatic jaundice that underwent DTT and AUS; one of them also had MRC. DTT was negative for bile in the 4 patients; AUS did not identify the gallbladder or showed it as small and irregular, or detected a fibrous cord; MRC identified a choledochal cyst but no associated EBA; surgery and pathology study documented EBA in all 4 patients. DTT associated with AUS demonstrated the absence of bile in the duodenum and gallbladder abnormality, respectively, leading to surgical exploration within 24 to 48 hours.