The Efficacy of Plastic Stent Anchoring to Reduce Migration of Metal Stent

Study Overview
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Brief Summary
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The aim of this study is to demonstrate that the group with an additional plastic stent to anchor the fully covered self expandable metal stent (FCSEMS) in patients with malignant biliary stricture has less stent migration than the group with FCSEMS only. The primary outcome is stent migration for 6 months. The secondary outcomes are stent related adverse events, stent patency, and overall survival.

Detailed Description
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Endoscopic retrograde biliary drainage using a plastic stent for the treatment of malignant biliary stricture has advantages in that it is easy to perform and low cost, but it has a short period of patency. To overcome this drawback, self-expandable metal stents (SEMS) have been developed and are now widely used. But, over time, the SEMS also develop restenosis, due to tumor ingrowth and the tissue hyperplasia caused by the stimulation of the surrounding tissues by the metal thin wire. To overcome these disadvantages, a fully covered self-expandable metal stents (FCSEMS) covered with a polymer coating have been developed and used. However, the FCSEMS showed more stent migration than the uncovered SEMS, which was not superior to the uncovered SEMS in terms of loss of stent function. In order to overcome the limitations of the FCSEMS, small-scale studies have shown that stent migration can be reduced by anchoring the FCSEMS using a plastic stent. To date, there has been no randomized controlled study to determine whether the FCSEMS can be anchored with a plastic stent in patients with malignant biliary stricture to reduce the stent migration. Therefore, the purpose of this study is to evaluate the efficacy of plastic stent anchoring to reduce migration of FCSEMS.

Official Title
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The Efficacy of a Fully Covered Self-expandable Metal Stent Anchored by a Plastic Stent for Anti-migration in the Management of Malignant Biliary Strictures: a Prospective Randomized Controlled Study

Conditions
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Malignant Biliary Stricture

Intervention / Treatment
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* Procedure: Plastic stent anchoring
* Procedure: FCSEMS


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Malignant biliary stricture requiring biliary drainage through endoscopic procedure Exclusion Criteria: Previous history of metal stent placement for malignant biliary stricture Hilar cholangiocarcinoma Malignant biliary stricture of intrahepatic duct A recurrence after surgery due to malignant biliary stricture Life expectancy less than 3 months Pregnancy If endoscopy is not possible based on the judgement of the researcher

Ages Eligible for Study
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Minimum Age: 20 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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No

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Treatment
Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: None (Open Label)


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: FCSEMS + Plastic<br>Insert a fully covered self expandable metal stent (FCSEMS) for malignant biliary stricture and insert an additional plastic stent to anchor the metal stent. (Plastic stent anchoring) | Procedure: Plastic stent anchoring<br>* Insert an additional plastic stent to anchor the fully covered self expandable metal stent.<br>Procedure: FCSEMS<br>* Insert a fully covered self expandable metal stent (FCSEMS) for malignant biliary stricture<br>|
| Active Comparator: FCSEMS<br>Insert only a fully covered self expandable metal stent (FCSEMS) without a plastic stent for malignant biliary stricture. | Procedure: FCSEMS<br>* Insert a fully covered self expandable metal stent (FCSEMS) for malignant biliary stricture<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Stent migration rate | Stent migration is classified as proximal or distal migration. Proximal stent migration is defined as any migration of the FCSEMS(Fully covered self expandable metal stent) into the bile duct, preventing its easy removal. Distal stent migration is defined in three ways. The first is when the stent is completely distally migrated without being lodged into the duodenum. The second is when the stent is lodged in the distal bile duct below the stricture. The third case is when the stent is migrated to the distal portion of the stricture and is lodged in the duodenum opposite the papilla | 6 months after randomization | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Stent-related adverse events | According to lexicon for endoscopic adverse events | 6 months after randomization | 
| Duration of stent patency | The period from the insertion of the stent to the point at which stent revision is required | 6 months after randomization | 
| Overall survival | Period from stenting to death | 6 months after randomization |