Also referred to as benign bile duct stricture, inflammatory bile duct stricture arises from biliary infections. It is characterized by inflammation, mucosal erosion, ulcer formation, fibrous tissue proliferation, and scar tissue formation, which ultimately lead to bile duct narrowing. The condition can occur at any site along the bile duct system, from intrahepatic bile ducts to the distal common bile duct. However, it is most frequently observed at the lower end of the common bile duct, the junction of the left and right hepatic ducts, and the horizontal segment of the left hepatic duct. The narrowing typically presents as annular or long-segment strictures. It is commonly secondary to conditions such as primary bile duct stones, suppurative cholangitis, or biliary ascariasis.
Upstream bile ducts dilate above the stricture, and in severe cases, cystic dilatation containing bilirubin stones may develop. Prolonged bile duct stricture can lead to varying degrees of liver parenchymal damage and fibrotic changes. In advanced cases, the affected liver lobe or segment may atrophy, while the remaining liver tissue undergoes compensatory hypertrophy. In late stages, the condition may result in biliary cirrhosis and portal hypertension.
Clinical Manifestations
The primary clinical presentation is recurrent episodes of cholangitis. Imaging studies such as ultrasound, CT, ERCP, and MRCP are helpful for preoperative diagnosis, though distinguishing benign strictures from malignant bile duct strictures may sometimes be challenging. Intraoperative cholangioscopy and cholangiography provide definitive diagnostic information.
Treatment
The treatment principle focuses on resolving the stricture and ensuring unobstructed bile drainage. Treatment options include the following:
- Endoscopic Sphincterotomy (EST): This is the first-line treatment for strictures at the lower end of the common bile duct that are less than 1.5 cm in length.
- Roux-en-Y Hepaticojejunostomy: This procedure is suitable for longer strictures at the lower end of the common bile duct.
- Surgical Reconstruction for Hilar Bile Duct Strictures: For strictures located at the hepatic hilum, bile duct reconstruction or Roux-en-Y hepaticojejunostomy may be performed.
- Hepatic Lobe Resection: In cases involving unilateral hepatic bile duct stricture accompanied by intrahepatic bile duct stones and liver atrophy, resection of the affected hepatic lobe may be performed.
Balloon dilatation is reserved for critically ill patients, while biliary stenting can be employed as a salvage therapy in cases of failed surgical intervention or balloon dilatation, particularly in patients with severe portal hypertension.