A Multi-Center, Randomized, Prospective, Clinical Study to Evaluate Safety and Efficacy of for patients with Unresectable Malignant Biliary Stricture

INTERVENTION: Medical Device, Procedure/Surgery : This clinical trial was conducted on patients with malignant extrahepatic bile duct stenosis, balloon dilatation‐laser coagulation using the Ndiya Graser surgical device 'Inbris', and the initial efficacy and safety of ERCP interventional procedure in which uncovered SEMS is inserted and ERCP interventional procedure in which uncovered SEMS is inserted It was designed to compare and evaluate the subjects, and a total of 14 subjects (dropout rate of 20%, 7 per group) from 2 domestic institutions were targeted. Among patients with malignant extrahepatic bile duct stenosis who voluntarily agreed to participate in this clinical trial after receiving a sufficient explanation of the clinical trial, the selection/exclusion criteria at the time of screening (visit 1) were judged to be suitable. The selected subjects are randomly assigned to the test group or control group in a 1:1 ratio, and ERCP intervention is performed according to the procedure of the assigned group. Subjects who have completed the procedure according to the observation items, clinical test items, and observation test method are moved to the ward and 4 hours (visit 3), 1 day (visit 4), 7 days (visit 5), At 30 days (Visit 6), 12 weeks (Visit 7), and 24 weeks (Visit 8), observe and test for safety and efficacy evaluation. Additionally, a safety/survival evaluation is conducted at 48 weeks (Visit 9). In general, hospitalized 2 days before the procedure and discharged after 7 days (visit 5) of the procedure, but the exact time of discharge from 1 day after the procedure (visit 4) is determined according to the standard procedure of the clinical trial institution and the judgment of the investigator. Variables for evaluating the effectiveness of clinical trial medical device CONDITION: Neoplasms PRIMARY OUTCOME: Clinical success rate Complication rate Duration of stent patency Survival Rate Technical success rate SECONDARY OUTCOME: Treatment Emergent Adverse Event, TEAE INCLUSION CRITERIA: 1. Adult males and females aged 19 years or older who voluntarily gave written consent after hearing the explanation of the purpose and method of this clinical trial and the foreseeable risks and inconveniences caused by the clinical trial 2. When malignant extrahepatic bile duct stricture is confirmed histopathologically ? Malignant bile duct stenosis due to bile duct cancer, gallbladder cancer, pancreatic cancer, or other malignant tumors is also applicable. 3. Malignant extrahepatic bile duct stenosis that cannot be surgically resected, a high‐risk group for surgery, or the patient does not want surgery 4. When the bile duct stricture segment is at least 1 cm away from the port of the liver 5. If the predicted survival period is more than 3 months as of the screening date 6. If KPS (Karnofsky Performance Status) = 60% 7. If you are willing to participate in a clinical trial, adhere to treatment and procedures, and visit the hospital fo