Early differentiation of extrahepatic biliary atresia from intrahepatic cholestasis is important. Hepatobiliary scintigraphy is an excellent noninvasive investigation for ruling out extrahepatic biliary atresia. This study aimed at identifying the role of ursodeoxycholic acid (UDCA), a choleretic agent, in conjunction with hepatobiliary scintigraphy in differentiating extrahepatic biliary atresia from neonatal hepatitis.
Methods: Fifty-one infants (42 male, 9 female) aged 0.3-5.5 mo (mean, 2.9 mo) presenting with neonatal jaundice underwent 99mTc-mebrofenin hepatobiliary scintigraphy. For patients who did not show any excretion of tracer into the intestine till 24 h, the study was repeated after oral administration of UDCA (20 mg/kg every 12 h) for 48-72 h. Ultrasonography and, if required, liver biopsy and intraoperative cholangiography were used with clinical data such as stool color and serologic and other etiologic investigations to form a final diagnosis.
Results: Of 51 patients, 19 showed biliary excretion in the first study, ruling out extrahepatic biliary atresia. Neonatal hepatitis was the final diagnosis in these. Of the remaining 32 patients, 12 nonexcretors converted to excretors after UDCA treatment, whereas 20 still showed no biliary drainage. Four nonexcretors on scintigraphy had a final diagnosis of neonatal hepatitis with galactosemia; the remaining 16 had extrahepatic biliary atresia. The specificity of hepatobiliary scintigraphy in ruling out extrahepatic biliary atresia improved from 54.3% to 88.6% (P < 0.001) after UDCA treatment. None of the patients experienced any ill effects from UDCA administration.
Conclusion: Pretreatment with UDCA significantly improves the specificity of hepatobiliary scintigraphy in ruling out extrahepatic biliary atresia as a cause of prolonged neonatal jaundice.