A Randomized Trial Comparing the Adenoma Detection Rates Between EndoRings Colonoscopy (EC) and Standard Colonoscopy (SC).
Phase: NA
Conditions: Colorectal Adenoma, Colorectal Polyp, Colon Cancer
Sponsor: Indiana University

01/22/18 
 
 
 
A randomized trial comparing the adenoma detection rates between 
EndoRings colonoscopy (EC) and Standard colonoscopy (SC). 
 
 
NCT03418662 
 
 

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A randomized trial comparing the adenoma detection rates between 
EndoRings colonoscopy (EC) and Standard colonoscopy (SC). 
 
Primary Investigator: 
 
 
 
 
Dr. Douglas Rex 
Indiana University Hospital 
Indianapolis, IN 46202 
 
Introduction:  
 
During a standard colonoscopy, the folds within the colon can negatively impact the endoscope’s 
view, reducing the ability to detect polyps. In order to help remedy this issue, there is a new 
provisional device called ENDORINGS™ . This device is a short silicone rubber tube with 
flexible circular wings mounted on the tip of the colonoscope to facilitate endoscopic therapy. 
By flattening the colonic folds during withdrawal, this device could help to keep a suitable depth 
of the endoscope’s view field and, in turn, could prove to increase the adenoma detection rate.  
The EndoRings is designed to fit specific endoscopes (as designated on the packaging), supplied 
sterile and is single use only. This device could prove to be an improvement of the current 
design. 
 
Methods:  
 
Colonoscopies will be performed by Dr. Douglas Rex and a number of sub-investigators. 
Data that will be assessed from each colonoscopy include the following: 
1. APC (Adenoma per Colonoscopy) 
2. Total adenomas detected 
3. Total polyps detected 
4. Polyp detection rate (PDR) 
5. PPC (Polyp per Colonoscopy) 
6. Effect on re-scope intervals 
7. Cecal intubation rate 
8. Comparison of the time required to reach the cecum 
9. Comparison of the withdrawal and total procedure time 
10. Effect of endoscopist experience on potential gain from using EndoRings 
11. Patient comfort score 
12. Problems encountered with equipment 
- 
Slippage of Endorings™ 
- 
Difficulty intubating with Endorings™ 
 

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Objectives: 
 
The primary endpoint of the study will be the adenoma detection rate of the 
EndoRings Colonoscopy (EC) compared to that of the Standard Colonoscopy (SC). 
Complications will be recorded, but the study will not be powered for complications. 
 
The study will help to establish a device that will result in improved adenoma detection 
rates when compared to a standard colonoscope.  
 
Criteria:  
 
 
Inclusion Criteria:  
 
• Age ≥ 18 
• Screening or Surveillance Colonoscopy 
• Able to provide written informed consent  
 
Exclusion Criteria:  
• Prior history of surgical resection of the large intestine 
• Known narrow colon or colon stenosis 
• Personal history of Colorectal cancer 
• History of Inflammatory bowel disease 
• Familial adenomatous polyposis syndrome (FAP) 
• Hyperplastic polyposis syndrome 
• Referral for incomplete colonoscopy or polyp clearance 
Randomization: 
Once a patient has been screened to ensure inclusion and exclusion criteria have been met 
and has provided consent for participation in the study, the subject will be randomized in 
a 1:1 ratio. Randomization outcomes include the Standard Colonoscopy or the EndoRings 
Colonoscopy.  
Statistical Analysis & Sample Size:  
The primary analysis compares the adenoma detection rate between the EC group and the 
SC group. It is assumed that the proportion of patients with at least one adenoma would 
be 25% with SC and 35% with EC colonoscopy.  

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A two group Chi-Square test with a 0.05 one-sided significance level will have 80% 
power to detect a difference of 10% ADR between the two groups (odds ratio of 1.615) 
when the sample size in each group is 259, a total sample size of 518 subjects.  
The final sample size will be 569 after adding the 10% expected drop-out rate. 
Interim analysis will be performed after the 200th patient is enrolled to assess device 
performance and protocol amendment.   
Data Integrity and Safety 
All paper charts pertaining to the patient will be kept under lock and key in 
coordinators office away from the endoscopy area. The data entry will be performed 
into an excel file which will be stored on an internal network drive with encryption and 
password security. Only approved personnel by the IRB will have access to the file 
storage.  This file will also not have any identifiable patient information.  A study log 
with the identifiable information will be kept in a separate folder to enable the 
investigators to assist in any research audit. No procedural data except the date of 
examination will be entered into this log.  
 
Any subject who wishes to withdraw from this investigation on his/her own accord and 
for whatever reason is entitled to do so without obligation and prejudice to further 
treatment. In addition, the Investigator may decide for reasons of medical prudence, to 
withdraw a subject. In either event, the Investigator will clearly document the date and 
reason(s) for the subject’s withdrawal from this investigation in the CRF and should 
indicate whether or not he considers it was related to the study interventions.