Comparison of Efficacy Between a Newly Designed Covered Stent and Uncovered Stent for Malignant Colorectal Obstruction

Study Overview
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Brief Summary
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Acute colorectal obstruction has been reported to occur in 7 - 29% of all colorectal malignancies, but emergent surgical decompression is associated with high morbidity and mortality rates. Recently, self-expandable metal stents(SEMS) have been suggested as an alternative to surgery and effectively decompress the colonic obstruction and allow for bowel preparation and elective surgery. Theoretically, SEMSs are classified into uncovered stents and covered stents. Covered stents have the advantage of less frequent stent occlusion by tumor in-growth and the disadvantage of a high risk of stent migration, whereas uncovered stents are associated with less stent migration, although they appear to be more prone to tumor ingrowth. To overcome the drawbacks of conventional stents, a double-layered combination covered stent was developed. In the present study, the investigators evaluated the efficacy and safety of the newly designed covered stent by comparing it with the uncovered stent in patients with malignant colorectal obstruction.

Official Title
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Comparison of Efficacy Between a Newly Designed Covered Stent and Uncovered Stent for Malignant Colorectal Obstruction: a Prospective, Multicenter Study

Conditions
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Colorectal Cancer

Intervention / Treatment
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* Procedure: self-expandable metal stent insertion(covered stent)
* Procedure: self-expandable metal stent insertion(uncovered stent)


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: 20 85-year-old patients with malignant colorectal obstruction either by primary CRC or extracolonic malignancy Patients with clinical obstructive symptoms confirmed by CT or colonoscopy Exclusion Criteria: Patients with evidence of bowel perforation or peritonitis Cause of obstruction other than malignancy (bowel adhesion or benign stricture) Multiple stricture Lower rectal cancer obstruction (AV <5cm)

Ages Eligible for Study
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Minimum Age: 20 Years
Maximum Age: 85 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: Double


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: covered stent<br>newly designed covered stent group | Procedure: self-expandable metal stent insertion(covered stent)<br>* Stent insertion was performed by experienced endoscopists under fluoroscopy and by using through-the-scope methods. After the obstructing tumor was identified by endoscopy, a guidewire was introduced through the stricture under endoscopic and fluoroscopic controls. Then, the self-expandable colorectal covered stent delivery catheter was advanced through the working channel of the endoscope over the guidewire until the stent was positioned across the stricture. Upon releasing the stent delivery catheter, stent deployment was initiated proximally and progressed distally. Simple abdominal radiography was performed during and after the procedures to confirm proper stent placement and expansion.<br>|
| Active Comparator: uncovered stent<br>currently used uncovered stent group | Procedure: self-expandable metal stent insertion(uncovered stent)<br>* Stent insertion was performed by experienced endoscopists under fluoroscopy and by using through-the-scope methods. After the obstructing tumor was identified by endoscopy, a guidewire was introduced through the stricture under endoscopic and fluoroscopic controls. Then, the self-expandable colorectal stent delivery uncovered catheter was advanced through the working channel of the endoscope over the guidewire until the stent was positioned across the stricture. Upon releasing the stent delivery catheter, stent deployment was initiated proximally and progressed distally. Simple abdominal radiography was performed during and after the procedures to confirm proper stent placement and expansion.<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Duration of stent patency between stent insertion and recurrence of obstructive symptoms | Time between stent insertion and recurrence of obstructive symptoms caused by tumor ingrowth, tumor overgrowth, or stent migration after stent placement | 2 years after the procedure | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Number of patients with technical success | Technical success: Adequate deployment across the entire length of the malignant strictures and proper stent expansion | 2 years after the procedure | 
| Number of patients with clinical success | Clinical success: Relief from obstructive symptoms as a result of sufficient improvement in stool passage without additional need for endoscopic or surgical re-intervention within 48 hours | 2 years after the procedure | 
| Number of patients with complications | Complications: stent obstruction, migration, perforation, bleeding, tenesmus, anal pain | 2 years after the procedure |