Value of prenatal ultrasonography in diagnosis of fetal biliary cystic malformation

Abstract

Objective To investigate the diagnositic value of ultrasonography in fetuses with cystic biliary malformation. Methods Three cases of cystic biliary malformation diagnosed in our hospital by prenatal ultrasound were followed up until surgery after birth. Results In all three cases.an anechoic cystic lesion was detected in the right upper abdomen at 16,26,34 weeks' gestation respectively, which were diagnosed as biliary cystic malformation by prenatal ultrasound. Two cases were confirmed as choledochal cyst by surgery, one case as biliary atresia. The maximum diameter during pregnancy of choledochal cyst were 3. 9 cm and 4.2 cm respectively, which increased steadily as gestational age advanced, with normal gallbladder in continuity with the choledochal cyst. But the largest diameter of the cyst in congenital biliary atresia was 1.7 cm and remained unchanged throughout the remaining pregnancy, the gallbladder could not be detected or an irregular small gallbladder was shown. Excision of the cyst and Roux-en-Y hepaticojejunostomy were successfully performed in all three cases. Postoperative course were uneventful. Conclusions Cyst diameter, change in size, gallbladder ultrasound pattern may allow to make a prenatal differential diagnosis of biliary tree cystic malformation. Small and stable cyst with an undetected gallbladder or small gallbladder is more suggestive of biliary atresia than choledochal cyst. Precise imaging may facilitate prenatal counseling and perinatal management. The outcomes had improved with earlier operations. Key words: Ultrasonography,prenatal; Choledochal cyst; Biliary atresia