A RCT of Low MBO Drainage Strategies

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.