Adenoma Miss Rate With Water Exchange vs Carbon Dioxide Colonoscopy

Study Overview
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Brief Summary
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This was an observational study comparing consecutive group of WE and CO2 insufflation in terms of right and proximal colon AMR by tandem colonoscopy.

Detailed Description
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This was a prospective observational study to assess how WE colonoscopy would fit into clinical and research practices. We first observed whether optimal WE colonoscopy decreased the AMR in the right and proximal colon in a tandem approach. If WE did lower the AMR as compared with data in the literature, a randomized RCT deserves to be studied. For the calculation of sample size in the upcoming RCT, the AMR in the CO2 group would be collected. The differences of the AMRs in the right and proximal colon determined by tandem colonoscopy using WE or CO2 insufflation would then be compared.

Official Title
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Water Exchange Colonoscopy Decreased Adenoma Miss Rates in the Right and Proximal Colon: An Observational Study Using A Tandem Colonoscopy Approach

Conditions
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Colonic Adenoma, Water Exchange Colonoscopy

Intervention / Treatment
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* Procedure: Water exchange colonoscopy
* Procedure: CO2 insufflation colonoscopy


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Consecutive patients aged 20 years or older undergoing colonoscopy for screening and surveillance indications were considered for enrollment. Exclusion Criteria: familial adenomatous polyposis and hereditary non-polyposis CRC syndrome, personal history of inflammatory bowel disease, previous colonic resection, inability to achieve cecal intubation, obstructive lesions of the colon, poor colon preparation, inability to completely remove a polyp, gastrointestinal bleeding, allergy to fentanyl or midazolam, American Society of Anesthesiology classification of physical status grade 3 or higher, mental retardation, pregnancy, and refusal to provide a written informed consent.

Ages Eligible for Study
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Minimum Age: 20 Years
Maximum Age: 75 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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Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Water exchange colonoscopy<br>During the insertion phase of the first-pass colonoscopy, water exchange (WE) method was used. WE entailed the infusion of water to open the lumen and sequentially suction of water. When the cecum was reached and after most of the water was suctioned to collapse the cecal lumen, CO2 was opened during the withdrawal phase of the first-pass colonoscopy. After the first complete withdrawal of the colonoscope, a second colonoscopic examination aided by CO2 insufflation during insertion and withdrawal was performed by the same endoscopist. The colonoscope was reinserted into the cecum as quickly as possible, and the entire colon was re-examined. Polyp resection was carried out during insertion and withdrawal of the first- and second-pass examinations. | Procedure: Water exchange colonoscopy<br>* During back-to-back colonoscopy, the first examination was completed with water exchange during insertion and CO2 insufflation during withdrawal. The second examination was completed with CO2 insufflation during both the insertion and withdrawal.<br>Procedure: CO2 insufflation colonoscopy<br>* During back-to-back colonoscopy, the first examination was completed with CO2 insufflation during both the insertion and withdrawal. The second examination was also completed with CO2 insufflation during both the insertion and withdrawal.<br>|
| CO2 insufflation colonoscopy<br>During the first-pass colonoscopy, the procedure was performed in the usual fashion, with minimal CO2 insufflation to aid insertion. Cleaning of colon was predominantly performed during withdrawal. After the first complete withdrawal of the colonoscope, a second colonoscopic examination aided by CO2 insufflation during insertion and withdrawal was performed by the same endoscopist. The colonoscope was reinserted into the cecum as quickly as possible, and the entire colon was re-examined. Polyp resection was carried out during insertion and withdrawal of the first- and second-pass examinations. | Procedure: CO2 insufflation colonoscopy<br>* During back-to-back colonoscopy, the first examination was completed with CO2 insufflation during both the insertion and withdrawal. The second examination was also completed with CO2 insufflation during both the insertion and withdrawal.<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Percentage of Overall Detected Adenomas Missed During the First Right-Colon Colonoscopy | Right-colon (cecum, A-colon, hepatic flexure) adenomas detected on the second-pass examination were used for the calculation of adenoma miss. Adenoma miss rate was calculated as the number of adenomas missed in the first colonoscopy divided by the total number of adenomas detected during both the first and second colonoscopies. | During procedure, approximately 1.5 hours | 
| Percentage of Overall Detected Adenomas Missed During the First Proximal-Colon Colonoscopy | Proximal-colon (cecum, A-colon, hepatic flexure, T-colon) adenomas detected on the second-pass examination were used for the calculation of adenoma miss. Adenoma miss rate was calculated as the number of adenomas missed in the first colonoscopy divided by the total number of adenomas detected during both the first and second colonoscopies. | During procedure, approximately 1.5 hours | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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Adenoma miss rate, Adenoma detection rate