Percutaneous US-guided Cholecystocholangiography with Microbubbles for Assessment of Infants with US Findings Equivocal for Biliary Atresia and Gallbladder Longer than 1.5 cm: A Pilot Study

Purpose To evaluate the feasibility of ultrasonographically (US) guided percutaneous cholecystocholangiography (PCC) for early exclusion of biliary atresia (BA) in infants suspected of having BA with equivocal US findings or indeterminate type of BA and a gallbladder longer than 1.5 cm at US. Materials and Methods This study was approved by the ethics committee; written informed parental consent was obtained. From February 2016 to December 2016, nine infants (four boys, five girls; mean age, 60.2 days; median age, 57 days; age range, 23-117 days) with conjugated hyperbilirubinemia and gallbladder longer than 1.5 cm at US were referred for US-guided PCC after US findings were equivocal for BA (n = 7) or the type of BA was unclear (n = 2). PCC was performed with a US machine with incorporated contrast pulse sequencing, contrast-specific software, and a linear transducer by injecting diluted contrast material via an 18-gauge needle. Images from US and US-guided PCC were evaluated in consensus by two radiologists. US criteria for BA were fibrotic cord sign (>2 mm) and gallbladder length-to-width ratio greater than 5.2. BA was excluded at PCC when contrast material was visualized in the gallbladder, common hepatic ducts, and common bile duct and during passage to the duodenum. Patients in whom BA was diagnosed after PCC underwent surgery or liver biopsy as the reference standard. Nonparametric and Fisher exact tests were used. Results US-guided PCC was successful in all patients. There were no procedural-related complications. BA was excluded in five of the nine patients. The median serum direct bilirubin level in these patients slightly decreased 1 week after PCC, from 91.1 μmol/L (interquartile range [IQR], 81.6-113.8 μmol/L) to 65.3 μmol/L (IQR, 57.8-74.7 μmol/L); however, this difference was not statistically significant (P = .062). BA was diagnosed in four patients, with the diagnosis confirmed at surgery (n = 2) or liver biopsy (n = 2). BA in two patients with unclear type of BA was defined as type III without patency of the common bile duct in one patient and as type III with patency of the common bile duct in the other. Conclusion In this highly selected group of infants with indeterminate type of BA or inconclusive US findings, US-guided PCC enabled the diagnosis of BA in four infants and the exclusion of BA in five. US-guided PCC may be a safe and effective tool to exclude BA early in infants with equivocal US findings. RSNA, 2017.