Percentage Visualized Mucosa as a Marker for the Quality of Colonoscopy

July 17, 2020 updated by: University Hospital Inselspital, Berne

Primary hypothesis: The percentage of mucosa visualized during the withdrawal of a colonoscopy with reference to the position in the colon by means of the scope-guide is an appropriate parameter for assessment of the quality of colonoscopy and correlates with the probability of the detection of adenomas.

Secondary hypothesis:

The investigators hypothesize that the percentage of visualized mucosa differs according patient specific parameters (e.g. gender, age, BMI, bowel preparation), procedure specific parameters (e.g. patient position, device, buscopan, fentanyl, withdrawal time) and investigator specific parameters (professional experience as resident and consultant).

Study Procedure/Evaluation:

The endoscopic images and scope guide from colonoscopy of 500 patients will be filmed. The investigators will correlate the detection of at least one adenoma in the cohort of included patients with the percentage of visualized mucosa during the withdrawal of a colonoscopy. Additional endpoints concerning the quality of the colonoscopy will be assessed as well.

Study Overview

Status

Unknown

Conditions

Intervention / Treatment

Detailed Description

PROJECT OBJECTIVES AND DESIGN 1.1 Hypothesis Primary hypothesis: The percentage of mucosa visualized during the withdrawal of a colonoscopy with reference to the position in the colon by means of the scope-guide is an appropriate parameter for assessment of the quality of colonoscopy and correlates with the probability of the detection of adenomas.

Secondary hypothesis:

The investigators hypothesize that the percentage of visualized mucosa differs according patient specific parameters (e.g. gender, age, BMI, bowel preparation), procedure specific parameters (e.g. patient position, device, buscopan, fentanyl, withdrawal time) and investigator specific parameters (professional experience as resident and consultant).

STUDY DESIGN AND PROCEDURES 2.1 Study Design: The investigators will perform a non-interventional, single center exploratory study. Only total colonoscopies will be included. All of the examinations will be performed by board-certified specialists or fellows in training, supervised by the former. The investigators will enroll only participants who will have an explicit indication, in other words who will get a colonoscopy anyway. Therefore, colonoscopies will be conducted for a wide variety of indications including, but not limited, to CRC screening, CRC/ adenoma surveillance, abdominal symptoms such as pain, irregular defecation (diarrhea or constipation), gastrointestinal occult or overt bleeding, family history of polyps or CRC, prior colonic resection, hereditary polyposis syndromes and inflammatory bowel diseases (IBD). Since the study does not pose any additional risk to the participants (the only thing which changes for the patient is that the endoscopic images from colonoscopy and scope guide will be filmed), the enrollment can be done during consultation hour, at the ward or shortly before a colonoscopy.

2.2 Recruitment, screening and informed consent procedure: Patients will be recruited by the project team in the Department of Visceral Surgery and Medicine at the Inselspital. The patient will be provided with information regarding the study. If the patient shows interest, the investigator will explain the study protocol, answer questions and check inclusion and exclusion criteria. For this study, no compensatory fee will be paid.

2.3 Study procedures: If the patient agrees to participate in the study and has signed the informed consent the colonoscopy will be performed in the usual setting and using general safety measures. The endoscopist will start filming all the phases of the colonoscopy and the position of the scope-guide simultaneously. Both films will be uploaded to the local server and then cut and analyzed with the help of iMovie. The only study procedure specific for the study is the filming and no other study specific measures will be taken.

Basic parameters of patient history and colonoscopy procedure will be recorded (compare CRF). As always, any findings of the colonoscopy will be reported to the participant/ patient after the procedure.

2.4 Withdrawal and discontinuation: If an individual withdraws informed consent after the colonoscopy or during the analysis of the data, he/she will be withdrawn from the project. All videos will be anonymized. In case of withdrawal, patient data and videos will not be considered for study purposes and will be deleted completely.

STATISTICS AND METHODOLOGY 3.1 Evaluation of Videos: All videos will be anonymized. Then the percentage of visible mucosa and lumen during withdrawal will be determined in each video. The scope-guide will allow to correlate the images with the position of the colonoscope within the colon. The investigators will record the amount of time spend in colon segments such as the cecum, ascending colon, right flexure, right transverse colon, left transverse colon, left flexure, descending colon, sigma and rectum. For each of these segments, the investigators will record the amount of time with good mucosa visibility and poor mucosa visibility.

In addition to manual analysis, computer-aided analysis and artificial intelligence methods will be developed to assist the evaluation of the videos. The development of computer-aided methods consists of two phases. In the first phase, frames in the video will be extracted as individual images. Experienced physicians will be assigned to annotate the images. The position of the scope-guide will be extracted for the annotation. Then a classifier based on deep neural network will be trained on these annotated images. The percentage of visible mucosa and lumen during withdrawal will be determined in each video based on the classification results of each individual frame. The classification according to the scope-guide will allow to correlate the images with the position of the colonoscope within the colon. The amount of time spending in colon segments such as the cecum, ascending colon, right flexure, right transverse colon, left transverse colon, left flexure, descending colon, sigma and rectum will be determined based on deep learning prediction results. Each frame will be classified to good mucosa visibility and poor mucosa visibility and the amount of time with good mucosa visibility and poor mucosa visibility of each of the segments will be determined accordingly. In the second phase, videos will be analysed directly with deep learning methods and the consistency between the frames will be explored during the analysis to improve the accuracy.

The investigators will also analyse advancements of the endoscope from the anus to the cecum. To this end, the time until each of the segments is reached will be recorded as well as all loops which have formed within the colon.

3.2 Statistical analysis plan 3.2.1. Statistical evaluation of the primary endpoint For evaluation of the primary endpoint (adenoma detection rate as a function of mucosa visibility) the investigators will rank all investigations regarding mucosa visibility and will divide the study population in 50% individuals with the best mucosa visibility and compare this number to the 50% of individuals with the worst mucosa visibility. They will compare the fraction of individuals with at least 1 detected adenoma to individuals without a detected adenoma (Fisher exact test). They will subsequently use multivariate logistic regression to correct for confounders (age, gender, family history of CRC, personal history of adenomas, advanced adenomas, carcinomas, BMI and bowel preparation).

3.2.2. Power analysis Our study is exploratory and no proper power analysis is possible. To provide an estimation the investigators assume that the effect of poor vs. good mucosa visibility will be as good as the effect of one of a number of technical devices recently tested in clinical studies to improve adenoma detection during colonoscopy. Such new technical devices (NTDs) include mucosa caps attached to the tips of the endoscope which flatten and stretch the mucosa or lenses to improve the field and angle of view. In a recent meta-analysis, NTDs increased the odds of adenoma detection by 35% (odds ratio 1.35) 25. In a screening colonoscopy, an adenoma detection rate of at least 20% would be expected 26 (i.e. 50 individuals with at least one adenoma among 250 individuals). In individuals with optimal mucosa visibility, this number would be 35% higher (i.e. 68 in 250 individuals). According to the power analysis using G* Power 3.1 27, 419 individuals would be needed to detect such a difference (i.e. 20% vs. 27% adenoma detection) with a power of 80% at an alpha level of 5%. The Investigators are aiming to include 500 individuals to account for an estimated 15% of investigations which could not be evaluated due to incomplete examinations or technical problems.

3.2.3 Statistical analysis of the secondary endpoints For the secondary outcomes, observed effects and interactions will be statistically substantiated by parametric and non-parametric tests and/ or multivariate analyses considering confounders as appropriate. A p-value <0.05 will be considered significant.

3.3 Handling of missing data: The nature of this exploratory study allows for some tolerance regarding missing data. Patients with incomplete or missing data/videos due to technical problems will be excluded from the study.

Study Type

Observational

Enrollment (Anticipated)

500

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Contact

Study Contact Backup

Study Locations

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Ages Eligible for Study

18 years and older (Adult, Older Adult)

Accepts Healthy Volunteers

No

Genders Eligible for Study

All

Sampling Method

Non-Probability Sample

Study Population

Individuals undergoing colonoscopy at Dept. of Visceral Surgery and Medicine, Inselspital Bern

Description

Inclusion Criteria:

  • Signed informed consent.
  • Ability to understand and follow study procedures and understand informed consent.
  • Complete colonoscopy.
  • Age at least 18 years.

Exclusion Criteria:

- Participation in another clinical study interfering with study procedures.

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

  • Observational Models: Cohort
  • Time Perspectives: Prospective

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Correlation of detection of at least one adenoma with the percentage of visualized mucosa
Time Frame: During the procedure

The investigators will correlate the detection of at least one adenoma in the cohort of included patients with the percentage of visualized mucosa during the withdrawal of a colonoscopy. In the Analysis of the investigators, the ADR will be corrected for confounders (age, gender, family history of CRC, personal history of adenomas, advanced adenomas, carcinomas, BMI and bowel preparation).

Mucosa visualization will be defined as the average of the visualized mucosa over all segments of the colon.
During the procedure

Secondary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Correlation of the percentage of visualized mucosa (see above) with the number of polyps, number of adenomas, number of advanced adenomas
Time Frame: During the procedure
Correlation of the percentage of visualized mucosa (see above) with the number of polyps, number of adenomas, number of advanced adenomas
During the procedure
In which segment of the colon is the visualization worst
Time Frame: During the procedure
In which segment of the colon is the visualization worst
During the procedure
Which factors influence the visualization of the colon mucosa
Time Frame: During the procedure
Which factors influence the visualization of the colon mucosa (bowel preparation, withdrawal time, device (colonoscope) selection, water vs. air immersion technique, buscopan, fentanyl, change of position of patient (supine position, lateral position) etc.)
During the procedure
Change of visualized mucosa during training of a gastroenterology resident (learning curve)
Time Frame: During the procedure
Change of visualized mucosa during training of a gastroenterology resident
During the procedure
Differences in percentage visualized mucosa between individual board-certified gastroenterologists according to years of professional experience and numbers of previous endoscopies
Time Frame: During the procedure
Differences in percentage visualized mucosa between individual board-certified gastroenterologists according to years of professional experience and numbers of previous endoscopies
During the procedure
Differences in percentage of visualized mucosa in men vs. women
Time Frame: During the procedure
Differences in percentage of visualized mucosa in men vs. women
During the procedure
Speed of advancing the endoscope during the first phase of colonoscopy under the conditions mentioned above (bowel preparation, sedation parameters, position, gender, level of professional experience).
Time Frame: During the procedure
Speed of advancing the endoscope during the first phase of colonoscopy
During the procedure
Loops in the colon (alpha-loop, reverse alpha-loop, N-loop) during advancing the endoscope and the influence of the parameters described under outcome 8)
Time Frame: During the procedure
Loops in the colon (alpha-loop, reverse alpha-loop, N-loop) during advancing the endoscope and the influence of the parameters described under outcome 8)
During the procedure
9) The above mentioned primary and secondary end-points will also be assessed using automated image analysis algorithms and artificial intelligence
Time Frame: During the procedure
9) The above mentioned primary and secondary end-points will also be assessed using automated image analysis algorithms and artificial intelligence
During the procedure

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

University Hospital Inselspital, Berne

Investigators

  • Study Director: Benjamin Misselwitz, Prof., University Hospital Inselspital, Berne

Publications and helpful links

The person responsible for entering information about the study voluntarily provides these publications. These may be about anything related to the study.

General Publications

Helpful Links

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start (Actual)

June 8, 2020

Primary Completion (Anticipated)

May 19, 2022

Study Completion (Anticipated)

May 19, 2022

Study Registration Dates

First Submitted

July 7, 2020

First Submitted That Met QC Criteria

July 17, 2020

First Posted (Actual)

July 22, 2020

Study Record Updates

Last Update Posted (Actual)

July 22, 2020

Last Update Submitted That Met QC Criteria

July 17, 2020

Last Verified

July 1, 2020

More Information

Terms related to this study

Other Study ID Numbers

  • 2020-00074

Plan for Individual participant data (IPD)

Plan to Share Individual Participant Data (IPD)?

Undecided

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

No

Studies a U.S. FDA-regulated device product

No

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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