Comparing the Efficacy and Safety of Holmium Laser Lithotripsy Versus Electrohydraulic Lithotripsy for the Treatment of Difficult Choledocholithiasis and Pancreatic Duct Stones

Inclusion Criteria: * Age 19-85 years * Signed written informed consent. * Presence of one or more biliary (common bile duct or intrahepatic) or pancreatic duct stones that are deemed "difficult" based on at least one of the following criteria: * Stone diameter ≥ 15 mm in any single dimension as measured on prior cross-sectional imaging (CT, MRCP, or EUS). * Presence of an impacted stone that cannot be dislodged with a standard balloon or basket. * Stone located proximal to a benign biliary or pancreatic duct stricture. * Documented failure of stone extraction during a prior ERCP attempt using standard techniques (e.g., sphincterotomy with balloon/basket extraction). Exclusion Criteria: * Pregnancy: Repeated ERCP would be delayed until after delivery if possible * Clinically significant, uncorrectable coagulopathy (defined as INR \> 1.5 or platelet count \< 50,000/μL). * Surgically altered upper gastrointestinal anatomy that precludes conventional ERCP access (e.g., Roux-en-Y gastric bypass), unless an alternative access route (e.g., laparoscopy-assisted or EUS-directed) is planned as the standard of care. * Known or highly suspected malignant biliary or pancreatic stricture associated with the stone. * Acute pancreatitis at the time of screening, unless it is gallstone pancreatitis with persistent biliary obstruction, for which ERCP is therapeutically indicated. * Severe cardiopulmonary disease or other comorbidities that, in the judgment of the investigator, would make the patient an unsuitable candidate for a prolonged endoscopic procedure under general anesthesia. * Known life expectancy of less than 6 months. * Inability or unwillingness to comply with study procedures or follow-up requirements.