A Study Between Two Instrument Generations to Improve Adenoma Detection in Screening Colonoscopy

Study Overview
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Brief Summary
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Adenoma detection rate (ADR) is the most important parameter to measure outcome quality of (screening) colonoscopy. Since single improvements of imaging have not been able to improve ADR in many randomized studies, the present study tested the hypothesis that only multiple imaging improvements such as seen with two generation changes of colonoscopies - i.e. skipping one colonoscope generation - may be necessary before improvements in ADR can be measured. The investigators will test this hypothesis in the present randomized tandem study in 7 private practices in Hamburg and Berlin, in a pure screening colonoscopy setting, aiming at inclusion of 1200 patients > age of 55 years (screening colonoscopy cut-off in Germany). Exclusion criteria are symptomatic patients and colonoscopies planned for therapeutic reasons. Main outcome parameter is the ADR (rate of patients with at least one adenoma/all patients).

Detailed Description
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The study was a prospective multicenter randomized study involving 7 private practice gastroenterology offices with a total of 14 experienced examiners (> 2000 colonoscopies), performed between November 2013 and September 2016 (sets of instruments were made available to 3-4 centers each during 6-12 months).Study population: Patients were selected from the screening colonoscopy list (age ≥ 55 years), with further inclusion criteria being status 1 and 2 of the ASA classification. After informed consent, patients were randomized using sealed envelopes per center to one of either of the two study groups 190 C group (intervention group), examination with the latest generation colonoscope (190 series CF or PCF colonoscopies, Olympus Corp, Hamburg, Germany). 165 C group (control group), examination with the 160/5 generation colonoscope (Olympus Corp, Hamburg, Germany), Each patient underwent bowel preparation in accordance with local practice of the centers. Bowel cleansing quality was segmentally assessed using a modified overall Boston Bowel Preparation Scale. Introduction and withdrawal times were measured, and times required for biopsies and polypectomies were considered separately, i.e. overall and diagnostic only withdrawal times were recorded separately. Polyps were documented with regards to location (caecum, ascending, transverse and descending colon, sigmoid and rectum), size and morphology using the Paris classification (polypoid pedunculated or sessile, non-polypoid slightly elevated/flat/depressed, ulcerous). Polyps were then resected using biopsy forceps or cold snare or conventional polypectomy according to local standards. Histology of resected polyps was analyzed by local private practice specialized GI pathologists according to the Vienna classification with regards to dysplasia grade and the presence of serrated adenomas; final histologic categories were hyperplastic, adenomatous [tubulous, villous, tubulovillous, serrated (traditional or sessile serrated)]. Small distal rectal polyps were not systematically biopsied or resected, due to a very high likelihood to be hyperplastic.

Official Title
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A Randomized Comparative Study Between Two Instrument Generations to Improve Adenoma Detection in Screening Colonoscopy

Conditions
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Adenoma Detection Rate

Intervention / Treatment
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* Procedure: screening colonoscopy


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: screening colonoscopy, age ≥ 55 years status 1 and 2 of the ASA classification signed informed consent Exclusion Criteria: Symptoms indicative of colorectal disease such as colonic bleeding, significant diarrhea, obstipation and change in bowel habits Known colonic disease for further evaluation (e.g. inflammatory bowel disease, polyps for resection) Surveillance after polypectomy or colon tumor surgery Anticoagulants preventing biopsy or polypectomy Poor general condition (ASA III or more) Incomplete colonoscopy planned

Ages Eligible for Study
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Minimum Age: 55 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 |
| --- | --- |
| Olympus 190<br>Olympus colonoscope 190 C (intervention group), screening colonoscopy examination with the latest generation colonoscope (190 series CF or PCF colonoscopies, Olympus Corp, Hamburg, Germany). | Procedure: screening colonoscopy<br>* Introduction and forwarding of the device up to caecum/terminal ileum. Then withdrawal and inspection of colonic wall. Biopsies and polypectomies if necessary. overall and diagnostic (only withdrawal) times being recorded separately. Polyps are documented with regards to location (caecum, ascending, transverse and descending colon, sigmoid and rectum), size (open forceps or snare for comparison) and morphology using the Paris classification (polypoid pedunculated or sessile, non-polypoid slightly elevated/flat/depressed, ulcerous) Polyps were then resected using biopsy forceps or cold snare (for polyps < 5 mm), or conventional polypectomy according to local standards.<br>|
| Olympus 160/165<br>Olympus colonoscope 165 C (control group), screening colonoscopy examination with the 160/5 generation colonoscope (Olympus Corp, Hamburg, Germany), | Procedure: screening colonoscopy<br>* Introduction and forwarding of the device up to caecum/terminal ileum. Then withdrawal and inspection of colonic wall. Biopsies and polypectomies if necessary. overall and diagnostic (only withdrawal) times being recorded separately. Polyps are documented with regards to location (caecum, ascending, transverse and descending colon, sigmoid and rectum), size (open forceps or snare for comparison) and morphology using the Paris classification (polypoid pedunculated or sessile, non-polypoid slightly elevated/flat/depressed, ulcerous) Polyps were then resected using biopsy forceps or cold snare (for polyps < 5 mm), or conventional polypectomy according to local standards.<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Adenoma detection rate | adenoma detection rate (ADR) of 190 colonoscopes in comparison to 160/5 colonoscopes at the patient level (% of patients with at least one adenoma). | day 1 | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Adenoma rate | Adenoma rate calculated at the adenoma level (all adenomas/all patients) and as the number of adenomas per adenoma carrier. | through study completion, an average of 6 months | 
| Adenoma subgroups: size | Adenoma subgroups due to size (< 1 cm, > 1 cm) | through study completion, an average of 6 months | 
| Adenoma subgroups: form | Adenoma subgroups due to form (flat, sessile, pedunculated) | through study completion, an average of 6 months | 
| Adenoma subgroups: location | Adenoma subgroups due to location (right sided - down to left hepatic flexure, left sided - descending colon, sigmoid and rectum) | through study completion, an average of 6 months | 
| Adenoma subgroups: histology | Adenoma subgroups due to histologic subgroups (SSA, HGIN) | through study completion, an average of 6 months | 
| Cecal intubation rate | Cecal intubation rate per arm, all patients | through study completion, an average of 6 months | 
| complication rate | Complications in both groups | through study completion, an average of 6 months | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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Colonoscopy, ADR, Adenoma detection rate, colonoscopic imaging feature improvement, Olympus colonoscopes