Outcome of hepatobiliary scanning: preterm versus full-term cholestatic infants

Objectives The aims of this study were to evaluate the specificity of a non-draining hepatobiliary scintigraphy (HBS) for biliary atresia (BA) in preterm and full-term babies, to verify the relationship between non-draining scan and higher levels of direct bilirubin and to find an objective criterion to guide the time in performing HBS. Methods A total of 175 infants (113 males and 62 females, median age of 45 days) with 181 HBS performed in Tuen Mun Hospital between January 1998 and May 2010 were retrospectively analysed. A 'non-draining' scan was defined as one showing no excretion of radio labelled tracer into the small bowel 24 h after injection. The disease category, epidemiological and laboratory data were compared between infants having non-draining and draining scans. In addition, the predictive value of a negative scan for BA was compared between preterm and full-term infants. Results Twenty infants (11.4%) were surgically confirmed to have BA. A non-draining scan was found to be 100% sensitive for BA, and the specificity was 96% and 78% among full-term infants and preterm infants, respectively. The mean direct bilirubin values of infants with BA and intrahepatic cholestasis were 141.9 and 111.3 mu mol/L, respectively, which were significantly higher than 67.2 mu mol/L seen in infants with draining scans. This analysis shows that using direct bilirubin >= 63 mu mol/L as an objective criterion in guiding the time to perform HBS is most cost-effective. Conclusion Our data supported that using direct bilirubin >63 mu mol/L as an objective criterion in guiding the time to perform HBS will avoid unnecessary scans.