A RCT of Low MBO Drainage Strategies

Inclusion Criteria: 1. Age:18 years old or above; 2. Periampullary cancer/pancreatic cancer according to pathology or clinical judgment of more than 2 senior doctors; 3. Distal malignant bile duct obstruction (2cm away from the hepatic hilum); 4. Ultrasound evaluation shows that the accessible part of the bile duct has a width of ≥ 12mm; 5. The patient or family member is able to understand the research protocol and is willing to participate in this study, providing written informed consent. Exclusion Criteria: 1. Patients suffer from severe cardiovascular or pulmonary diseases who are unable to tolerate anesthesia or endoscopic examination; 2. Uncorrectable coagulation abnormalities or bleeding tendencies (INR\>1.5 or platelets\<50) × 109 /L); 3. There is a plan for subsequent surgical resection of the tumor, accompanied by severe infection or an expected survival period of less than 3 months; 4. Successful biliary drainage measures have been implemented, including but not limited to ERCP, ENBD, PTCD, and surgical procedures; 5. Previous surgical changes to the anatomical structure of the pancreas, gallbladder, stomach, and duodenum; 6. Pregnancy, lactation, or planned pregnancy; 7. Refusal to join or inability to provide informed consent; 8. Other researchers evaluated the unsuitability of enrollment.