Persistent biliary dilatation and stenosis in postoperative congenital choledochal cyst

Background/purpose Cholangitis and intrahepatic stones occur long after total cyst excision in patients with congenital choledochal cyst (CCC). Our study aimed to characterize morphological features of intrahepatic biliary dilatation and stenosis before and after total cyst excision, based on long‐term follow‐up data. Methods Pre‐ and postoperative morphological features of intrahepatic biliary dilatation were determined in 63 patients with CCC. Results Postoperatively, hepatic ductal dilatation persisted in 50 patients and hepatic ductal dilatation with stenosis in 35 patients. Hepatic duct stenosis was seen in 35 patients: unilateral hepatic duct stenosis in 21, and bilateral stenosis in 14. Stenosis at the confluence of the right and left hepatic ducts occurred more often in the cystic type of dilatation than in the cylindrical type and was seen more often on the left side than the right. Cases with postoperative cholangitis or intrahepatic stones featured stenosis at the confluence of left and both hepatic ducts ( n = 2); and alternating dilatation and stenosis of left hepatic ducts and branches ( n = 3). However, no statistical associations were observed between the hepatic ductal stenosis and cholangitis or stone formation ( p = 0.153). Conclusions Cystic‐type biliary dilatations persist postoperatively, frequently accompanied by ductal stenosis. Alternating dilatation and stenosis is a common morphological feature for postoperative cholangitis and stones.