The role of PTCS: The aging society is coming, the number of elderly patients with bile duct stones and biliary infection is increasing in our region, recurrent bile duct infections are sometimes fatal. PTCS can be used to remove stones from the common bile duct and intrahepatic bile duct, gallbladder stones, and is also a blessing for elderly patients in critical condition. It can also be used in elderly patients who cannot tolerate general anesthesia and surgery. It can also be used for the diagnosis and treatment of biliary strictures and biliary tumors.