intrahepatic bile duct stones

Intrahepatic bile duct stones refer to primary bile duct stones located above the bifurcation of the hepatic ducts, and the vast majority are pigment stones mainly composed of calcium bilirubinate. Although intrahepatic bile duct stones are part of primary bile duct stones, they have their own particularities. When coexisting with extrahepatic bile duct stones, their clinical manifestations are often similar to those of extrahepatic bile duct stones. Because intrahepatic bile duct stones are deeply located within the liver tissue, with complex branches and anatomical structures, and the location, number, and size of the stones are variable, diagnosis and treatment are far more difficult than for extrahepatic bile duct stones alone. To this day, they remain a disease of the hepatobiliary system that is difficult to manage and yields unsatisfactory therapeutic outcomes. The incidence of intrahepatic bile duct stones is relatively low abroad. In one series of 2,700 biliary surgeries, they accounted for only 1.3%, and most were formed by common bile duct stones secondary to gallbladder stones migrating upward into the intrahepatic bile ducts. However, in China, the incidence of intrahepatic bile duct stones is relatively high, especially in provinces such as Fujian, Jiangxi, and Shandong, where intrahepatic bile duct stones can account for 30-40% of biliary stones. The higher incidence may be related to biliary tract infections caused by Ascaris lumbricoides, and may also be related to low-protein, low-fat diets. Intrahepatic bile duct stones can be widely distributed in various branches of the bile ducts of both lobes, or can be confined to one area. They are most commonly found in the left lateral lobe or the right posterior lobe of the liver, possibly related to the greater curvature of the bile ducts in these areas and impaired bile drainage. In a series of 92 cases of intrahepatic bile duct stones from Zhongshan Hospital, isolated left hepatic duct stones accounted for 31.3%. Most intrahepatic bile duct stones in China are primary bile duct stones, predominantly calcium bilirubinate stones. Most intrahepatic bile duct stones are accompanied by extrahepatic bile duct stones.