A Retrospective Study Between Type I Cystic Biliary Atresia and Infantile Choledochal Cyst at a Tertiary Centre

Purpose: Type I cystic biliary atresia (CBA) is an uncommon variant of biliary atresia (BA) which is liable to misdiagnosis as infantile choledochal cyst (ICC). We assessed our experience with type I CBA and compared with that of ICC. Methods: Seven patients (4 males and 3 females) with type I CBA, receiving liver function detection, radiological imaging studies, liver/cyst histological examinations and radical surgery, were compared with 23 ICC patients (14 males and 9 females) admitted in our division during a 6-year period. Findings: The mean levels of total bilirubin (T-Bil), direct bilirubin (D-Bil), alanine aminotransferase (ALT), aspartate aminotransferase (AST) and alkaline phosphatase (AKP) in the type I CBA group were significantly higher than those in the ICC group (p<0.01). The mean diameter of the cyst in the type I CBA group was significantly smaller than that in the ICC group (p<0.01). All 7 patients in the type I CBA group were accurately diagnosed by magnetic resonance cholangiopancreatography (MRCP) preoperatively, being in accordance with the results of intraoperative cholangiography and liver/cyst histology. Six cysts (85.7%) in the type I CBA group had a fibroinflammatory wall with no biliary epithelial lining while all 23 (100%) cysts in the ICC group had normal biliary epithelial lining. Six infants (85.7%) with type I CBA cleared their jaundice (total bilirubin ≤20 μmol/L) within 6 months after a Kasai portoenterostomy or hepaticojejunostomy procedure. All patients with ICC were in good condition with no jaundice and cholangitis after the operation. Conclusions: While elevated T-BIL/D-BIL and AST/ALT/AKP as well as smaller gallbladder/extrahepatic cyst imply type I CBA, MRCP can provide further effective assistance in making a relatively accurate diagnosis before operation. Either hepaticojejunostomy or Kasai portoenterostomy could be chosen as an optimal procedure in the treatment of type I CBA.