Prospective Comparison of Large vs. Small Diameter Esophageal Stents for Palliation of Malignant Dysphagia

Study Overview
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Brief Summary
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Esophageal cancer often causes difficulty swallowing (dysphagia) that can be relieved by placement of a stent (a flexible, expandable tube that props open the blockage caused by the cancer). Stents are effective but can cause complications. Stents come in different diameters. The purpose of this study is to learn if stents of different diameters are more or less effective for treatment of dysphagia caused by esophageal cancer.

Detailed Description
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This prospective, randomized study was conducted at Tenwek Hospital in Bomet, Kenya, and was approved by the hospital's institutional review board (IRB) as well as the Kenya Medical Research Institute's Ethical Review Committee. Participants with dysphagia were recruited and provided signed informed consent prior to endoscopy. During endoscopy and after dilation of an obstructing esophageal tumor sufficient to permit passage of an endoscope, eligible participants were enrolled and randomized to receive either an 18 mm shaft/23 mm flange or 23 mm shaft/28 mm flange partially covered Ultraflex esophageal stent (Boston Scientific, Natick, Massachusets, USA). Stents were either 10 or 12 cm in length, and the endoscopist chose a stent length based on the length of the malignant stricture. One stent was placed in each subject. Follow-up was then obtained at scheduled intervals after stent placement (7 and 28 days, 3 months, then every 3 months), until the participant's death. Earlier follow-up visits were arranged if participants reported any new health concerns. Block randomization was performed using the sealed envelope technique, with 10 participants in each block; none of the study personnel at Tenwek Hospital had knowledge of the randomization sequence. Allocation was concealed from participants, caregivers, and study personnel until randomization occurred during an endoscopic procedure. After randomization, stent diameters were known to the endoscopy staff and listed in the medical record. All randomized participants correctly received a stent of the allocated diameter, and remained blinded to the stent diameter they received. At baseline and each follow-up visit body weight was recorded, as well as Karnofsky performance status score, dysphagia score (0=normal, no dysphagia; 1=can swallow most foods; 2=can swallow a soft diet; 3=can swallow fluids only; 4=unable to swallow saliva), current medications, and the presence or absence of 15 symptoms and 9 diagnoses (weakness, fever, vomiting, vomiting blood, melena, weak voice, difficulty breathing, cough, sputum, palpitations, heartburn, chest pain, hiccoughs, recurrent dysphagia, abdominal pain; anemia, gastrointestinal bleeding, esophago-respiratory fistula, arrhythmia, pneumonia, metastases, stent occlusion, stent migration, gastroesophageal reflux disease). In addition, all interval clinic visits, test results, endoscopy reports, and hospitalizations were reviewed.

Official Title
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Randomized, Prospective Comparison of Large vs. Small Diameter Esophageal Stents for Palliation of Malignant Dysphagia

Conditions
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Esophageal Cancer

Intervention / Treatment
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* Device: Self-expandable metal stent


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: age ≥ 18 years dysphagia due to unresectable esophageal cancer participant resides within 50 km of Tenwek Hospital tumor is ≤ 9 cm in length and > 2 cm distal to the upper esophageal sphincter (UES) no esophago-respiratory fistula (ERF) or suspected perforation is present Exclusion Criteria: unable to provide written informed consent

Ages Eligible for Study
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Minimum Age: 18 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 |
| --- | --- |
| Active Comparator: Small-diameter stent<br>Placement of a 23 mm self-expandable metal stent | Device: Self-expandable metal stent<br>* Placement of a self-expandable metal stent in the esophagus<br>* Other names: Ultraflex Esophageal Stents;|
| Active Comparator: Large-diameter stent<br>Placement of a 28-mm self-expandable metal stent | Device: Self-expandable metal stent<br>* Placement of a self-expandable metal stent in the esophagus<br>* Other names: Ultraflex Esophageal Stents;|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Relief of dysphagia | Number of participants with improvement in dysphagia score to <2 | 1 month following stent placement | 
| Complications | Number of participants who experience stent-related symptoms (including chest pain, recurrent dysphagia, hematemesis, melena, palpitations) or complications (including gastrointestinal hemorrhage, esophago-respiratory fistula, stent migration, stent occlusion) from the time of stent placement until death or 5-year follow-up. | from stent placement to death or 5 years of follow-up, whichever comes first | 
| Mortality | Time (in days) from stent placement to death, assessed by Kaplan-Meier analysis | from stent placement to death or 5 years of follow-up, whichever comes first | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Endoscopic re-intervention | Number of participants undergoing repeat endoscopy to diagnose or treat a stent-related problem at any time from stent placement to death or 5 year follow-up. | from stent placement to death or 5 years of follow-up, whichever comes first | 
| performance status | Karnofsky performance status, assessed by Kaplan Meier analysis, from stent placement to death or 5-year follow-up. | from stent placement to death or 5 years of follow-up, whichever comes first | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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esophagus, cancer