12-mm Partial Covered Versus Bare Self-Expandable Metallic Stents for Malignant Distal Biliary Obstruction (PCSEMS-12)

12-mm Partial Covered Versus Bare Self-Expandable Metallic Stents for Malignant Distal Biliary Obstruction: A Prospective, Randomized Clinical Study

Metallic stents are commonly used for biliary drainage in patients with unresectable malignant distal biliary obstruction. However, it is unclear whether a 12-mm partially covered self-expandable metallic stent or a 12-mm bare self-expandable metallic stent provides better effectiveness and safety. This prospective, randomized clinical trial will compare these two stent types in adult patients who have already undergone percutaneous transhepatic biliary drainage (PTBD) and are scheduled for metallic stent placement through the existing PTBD tract. A total of 60 participants will be enrolled. After stent placement, participants will be followed for 12 months, with assessments at 3, 6, and 12 months. The study will evaluate recurrent biliary obstruction, stent patency duration, reintervention, overall survival, and procedure-related complications. The results are expected to provide evidence for selecting the most appropriate 12-mm metallic stent for patients with unresectable malignant distal biliary obstruction.

Study Overview

• Status: Not yet recruiting
• Conditions: Malignant Biliary Obstruction; Biliary Obstruction; Malignant Distal Biliary Obstruction
• Intervention / Treatment: Device: 12-mm partially covered self-expandable metallic stent; Device: 12-mm bare self-expandable metallic stent

Detailed Description

Malignant distal biliary obstruction is commonly caused by pancreatic cancer, cholangiocarcinoma, gallbladder cancer, or metastatic malignancy. In patients with unresectable disease, biliary drainage with a self-expandable metallic stent is widely used as palliative treatment. Bare metallic stents have the advantage of firm fixation, but tumor ingrowth can lead to recurrent biliary obstruction. Covered metallic stents may reduce tumor ingrowth, but concerns remain regarding stent migration and other procedure-related complications. Although 10-mm stents have been studied previously, evidence remains limited regarding the comparative effectiveness and safety of 12-mm partially covered versus bare self-expandable metallic stents.

This study is a prospective, single-center, randomized clinical trial designed to compare a 12-mm partially covered self-expandable metallic stent with a 12-mm bare self-expandable metallic stent in patients with unresectable malignant distal biliary obstruction. Adult patients who have already undergone percutaneous transhepatic biliary drainage (PTBD) according to the institutional clinical protocol and are scheduled for metallic stent placement through the existing PTBD tract will be screened for eligibility. After written informed consent is obtained, eligible participants will be randomly assigned in a 1:1 ratio to receive either a 12-mm partially covered self-expandable metallic stent or a 12-mm bare self-expandable metallic stent.

All procedures will be performed through a percutaneous transhepatic approach using the existing PTBD tract. After assessment of the biliary stricture, an appropriately sized 12-mm metallic stent will be placed. Participants will be followed for 12 months after stent placement, with follow-up assessments at 3, 6, and 12 months. The primary outcome is the cumulative incidence of recurrent biliary obstruction within 12 months after the procedure. Secondary outcomes include time to recurrent biliary obstruction, overall recurrent biliary obstruction rate, causes of recurrent biliary obstruction, reintervention, overall survival, and procedure-related complications such as pancreatitis, cholecystitis, bleeding, perforation, and cholangitis. The results of this study are expected to provide evidence to guide selection of the most appropriate 12-mm metallic stent in patients with unresectable malignant distal biliary obstruction.

• Study Type: Interventional
• Enrollment (Estimated): 60
• Phase: Not Applicable

Contacts and Locations

• Study Contact: Name: Woosun Choi, MD, PhD; Phone Number: +82-2-6299-2681; Email: radiochoi527@gmail.com
• Study Contact Backup: Name: Jinyoung Choi, MD; Phone Number: +82-2-6299-2681; Email: hananox@naver.com

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Adult; Older Adult
• Accepts Healthy Volunteers: No

Description

Inclusion Criteria:

• Patients who voluntarily provide written informed consent after receiving sufficient explanation of the study purpose, methods, and potential benefits and risks
• Adults aged 19 years or older
• Patients diagnosed with unresectable malignant distal biliary obstruction based on imaging studies (CT, MRI, ERCP, etc.) or histologic confirmation
• Patients who have already undergone percutaneous transhepatic biliary drainage (PTBD) according to the institutional clinical protocol and are scheduled for metallic stent placement through the existing PTBD tract

Exclusion Criteria:

• Patients with a previous history of biliary metallic stent placement
• Patients with upper biliary obstruction (hilar level or above)
• Patients with other major biliary lesions in addition to malignant distal biliary obstruction
• Patients for whom the investigator judges that study conduct or data collection would be markedly difficult

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Treatment
• Allocation: Randomized
• Interventional Model: Parallel Assignment
• Masking: Single

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: 12-mm Partially Covered SEMS Group; Participants in this arm will receive a 12-mm partially covered self-expandable metallic stent (ComVi Biliary Stent) through the existing PTBD tract for unresectable malignant distal biliary obstruction.	Device: 12-mm partially covered self-expandable metallic stent; A 12-mm partially covered self-expandable metallic stent placed through the existing percutaneous transhepatic biliary drainage (PTBD) tract for internal biliary drainage in patients with unresectable malignant distal biliary obstruction.
Active Comparator: 12-mm Bare SEMS Group; Participants in this arm will receive a 12-mm bare self-expandable metallic stent (Niti-S Biliary Uncovered Stent) through the existing PTBD tract for unresectable malignant distal biliary obstruction.	Device: 12-mm bare self-expandable metallic stent; A 12-mm bare self-expandable metallic stent placed through the existing percutaneous transhepatic biliary drainage (PTBD) tract for internal biliary drainage in patients with unresectable malignant distal biliary obstruction.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Cumulative incidence of recurrent biliary obstruction (RBO) within 12 months after the procedure	Cumulative incidence of recurrent biliary obstruction related to the initially inserted study stent (index stent).	12 months after the procedure

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Time to recurrent biliary obstruction (Time to RBO; stent patency duration)	Time from the procedure to recurrent biliary obstruction of the initially inserted study stent (index stent); stent patency duration.	Up to 12 months after the procedure
Overall rate of recurrent biliary obstruction (RBO)	Overall rate of recurrent biliary obstruction during follow-up.	Up to 12 months after the procedure
Overall survival	Overall survival after the procedure.	Up to 12 months after the procedure
Rate of procedure-related complications	Procedure-related complications, including pancreatitis, cholecystitis, bleeding, perforation, and cholangitis.	From immediately after the procedure up to 12 months after the procedure
Number of participants by cause of recurrent biliary obstruction	Number of participants with recurrent biliary obstruction classified by cause, including tumor ingrowth, tumor overgrowth, sludge, and stent migration.	Up to 12 months after the procedure
Rate of reintervention	Rate of participants requiring reintervention, including additional metallic stent p	Up to 12 months after the procedure
Number of reinterventions	Total number of reinterventions, including additional metallic stent placement, PTBD exchange, or PTBD extension.	Up to 12 months after the procedure

Collaborators and Investigators

• Sponsor: Chung-Ang University Hosptial, Chung-Ang University College of Medicine
• Collaborators: OSYMED CO., Ltd.
• Investigators: Principal Investigator: Woosun Choi, MD, PhD, Associate Professor, Department of Radiology, Chung-Ang University Hospital

Study record dates

Study Major Dates

• Study Start (Estimated): May 1, 2026
• Primary Completion (Estimated): December 31, 2029
• Study Completion (Estimated): December 31, 2029

Study Registration Dates

• First Submitted: April 24, 2026
• First Submitted That Met QC Criteria: April 24, 2026
• First Posted (Actual): April 30, 2026

Study Record Updates

• Last Update Posted (Actual): May 6, 2026
• Last Update Submitted That Met QC Criteria: April 30, 2026
• Last Verified: April 1, 2026

More Information

Terms related to this study

• Keywords: PTBD; stent patency; 12-mm metallic stent; partially covered self-expandable metallic stent; bare self-expandable metallic stent; malignant distal biliary obstruction; recurrent biliary obstruction
• Other Study ID Numbers: 2603-004-677

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: NO

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No