Comparisons between cystic biliary atresia and choledochal cyst: a controlled clinical study

Abstract

Objective To explore the clinical parameters of cystic biliary atresia (CBA) versus choledochal cyst (CC) in neonates or young infants. Methods Retrospective analysis was performed for the clinical data of 96 CBA/CC patients aged under 120 days from January 2013 to November 2015. They were divided into CBA (n=29) and CC (n=67) groups by the findings of intraoperative cholangiography. Two groups were compared with regards to laboratory data, preoperative ultrasonographic features, intraoperative cholangiography and histopathology. CBA group included 9 boys and 20 girls with an operative age of (51.8±24.0) days and a weight of (4.6±0.8) kg; CC group had 20 boys and 47 girls with an operative age of (50.0±26.4) days and a weight of (4.4±1.0) kg. Results The median values of glutamic-pyruvic transaminase (ALT), glutamic-oxalacetic transaminease (AST), total bilirubin (TBil), direct bilirubin (DBil) and total bile acid (TBA) in CBA and CC groups were 59.4 vs 29.5 U/L, 140.1 vs 44.0 U/L, 189.9 vs 87.4 μmol/L, 84.9 vs 14.3 μmol/L and 111.6 vs 8.7 μmol/L respectively. And significant inter-group differences existed in ALT, AST, TBil, DBil and TBA (P<0.001). However, the median gamma-glutamyl transpeptidase (GGT) was 331.9 vs 225.5 U/L. And there were insignificant inter-group statistical differences. The maximal longitudinal and transverse diameters of cyst were (2.5±1.2) and (1.6±0.8) cm in CBA group versus (4.7±2.2) and (3.4±1.8) cm in CC group. And cyst size was obviously smaller in CBA group than that in CC group (P<0.001); in CBA group, small gallbladder (n=4, 13.8%), atrophic gallbladder (n=21, 72.4%), intra-hepatic bile duct dilation (n=6, 20.7%) and triangular cord sign (n=9, 31.0%); in CC group, small gallbladder (n=1, 1.5%), intra-hepatic bile duct dilation (n=29, 43.3%) and none with atrophic gallbladder or triangular cord sign. All preoperative ultrasonographic features had significant inter-group differences (P<0.05 or P<0.001). Histopathological results showed that CBA and CC groups exhibited varying degrees of liver fibrosis and bile duct proliferation. However, the degrees of liver fibrosis and bile duct proliferation were milder in CC group than those in CBA group. Conclusions CBA should be suspected ultrasonically if there are small cysts along with characteristic manifestations of BA and elevated laboratory data. And cholangiography should be performed timely for confirming the diagnosis and surgery scheduled promptly. GGT is an insensitive indicator in distinguishing CBA from CC. Key words: Biliary atresia; Cystic biliary atresia; Choledochal cyst; Clinical parameters