Full Spectrum vs. Standard Forward-viewing Colonoscopy

We changed the anticipated number of subjects enrollment for study: NCT02117674 from 120 to 200 based on the following sample size estimation:

Tandem colonoscopies studies results, show that novel endoscopic technologies detect about 20% more adenomas than those conventional colonoscopy does (missed adenomas). Since FUSE colonoscopy cannot be considered as a perfect examination, we hypothesize that conventional colonoscopy will detect one third of the missed adenomas that FUSE detects in a similar setting. Therefore a sample size of 120 adenomas achieves 80% power to detect an odds ratio of 3.0 using a two-sided McNemar test with a significance level of 0.05. The odds ratio is equivalent to a difference between two paired proportions of 14% which occurs when the proportion of detected missed adenomas during FUSE is 21% and the proportion of missed adenomas during conventional colonoscopy is 7%. During one year period before the study initiation, our colonoscopy performance quality data show that we detect a mean number of adenomas per patient equal of 0.7 in a population similar to the one recruited in our study. Therefore, 172 patients overall will be required to detect 120 adenomas. Given the uncertainty of our estimation and in order to cope with patients exclusions, withdrawals and unexpected incomplete colonoscopies, we decided to recruit 200 patients.

A more extensive description regarding the investigators study is provided in the following fields.

• standard forward-viewing colonoscopy (Procedure), also known as conventional colonoscopy: examination of the colon with a conventional colonoscope
• full-spectrum colonoscopy (Procedure), also known as fuse endoscopy: examination of the colon with full-spectrum colonoscope
• right colon retroflexion (Procedure), also known as retroflexion: examination of the right colon with scope retroflexion (both with conventional and fuse scope)

Primary outcomes

• polyp detection rate [one week]: per colon segment and for the entire colon

Secondary outcomes

• colonoscopy completion [one week]: colonoscopy completion rate
• procedure time [one week]: intubation and withdrawal time
• adverse events [one week]: adverse events rate
• endoscopist's satisfaction [one week]: endoscopist's satisfaction quantified using a scale from 0 (not satisfied) to 10 (completely satisfied)
• feasibility of the retroflexion in the right colon by trainee [one week]: feasibility of retroflexion in the right colon by trainee, meaning if the trainee managed to perform the right colon retroflexion or not
• feasibility of retroflexion in the right colon by the consultant [one week]: feasibility of retroflexion in the right colon by the consultant, meaning if the consultant managed to perform the right colon retroflexion or not
• patients' satisfaction [one week]: patients' satisfaction, quantified using a scale from 0 (not satisfied at all) to 10 (completely satisfied)

Sex: All, ages: 18 Years to 80 Years

Inclusion Criteria:

* adults undergoing elective screening or surveillance colonoscopy
* symptomatic adults with indication for colonoscopy

Exclusion Criteria:

* age over 80 years
* poor overall health (ASA III, IV)
* recent abdominal surgery
* presence of abdominal wall hernias
* active colitis
* multiple right colon diverticula
* previous bowel resection
* inflammatory bowel disease
* polyposis syndromes

• Hewett DG, Rex DK. Miss rate of right-sided colon examination during colonoscopy defined by retroflexion: an observational study. Gastrointest Endosc. 2011 Aug;74(2):246-52. doi: 10.1016/j.gie.2011.04.005. Epub 2011 Jun 15. PMID 21679946
• Gralnek IM, Segol O, Suissa A, Siersema PD, Carr-Locke DL, Halpern Z, Santo E, Domanov S. A prospective cohort study evaluating a novel colonoscopy platform featuring full-spectrum endoscopy. Endoscopy. 2013 Sep;45(9):697-702. doi: 10.1055/s-0033-1344395. Epub 2013 Aug 12. PMID 23939509
• Results publication: Papanikolaou IS, Apostolopoulos P, Tziatzios G, Vlachou E, Sioulas AD, Polymeros D, Karameris A, Panayiotides I, Alexandrakis G, Dimitriadis GD, Triantafyllou K. Lower adenoma miss rate with FUSE vs. conventional colonoscopy with proximal retroflexion: a randomized back-to-back trial. Endoscopy. 2017 May;49(5):468-475. doi: 10.1055/s-0042-124415. Epub 2017 Jan 20. PMID 28107765

• KONSTANTINOS TRIANTAFYLLOU, Prof, Study director, Hepatogastroenterology Unit, 2nd Department of Internal Medicine and Research Unit, Attikon University General Hospital, University of Athens, Greece
• GEORGE ALEXANDRAKIS, Dr, Study director, 417 NIMTS VETERANS HOSPITAL