EditorialUpdate on Colonoscopic Imaging and Projections for the Future
Section snippets
Increasing Detection: Exposing Hidden Mucosa
A wide angle (≥170°) of view has been compared with a standard (140°) angle in 3 randomized trials.5, 6, 7 The only benefit observed was that some operators can withdraw faster without decreasing adenoma detection. The theoretical gain in mucosal exposure with 170° is about 5% compared with 140° when the scope is withdrawn along a centering line,8 but manipulation of the scope tip likely compensates for this gain.
Hooded colonoscopy has been evaluated in 10 randomized trials.1, 9, 10, 11, 12, 13
Increasing Detection: Highlighting Flat Lesions
Pan-colonic chromoendoscopy increases the detection of small flat adenomas4 but is considered too time consuming to be used for routine colonoscopy.
Electronic highlighting of flat lesions has been attempted with narrow band imaging (NBI) and postimaging processing methods including Fuji Intelligent Chromo Endoscopy (FICE) (Fujinon, Wayne, NJ) and I-Scan from Pentax (Montvale, NJ). There are too few data with I-Scan to make an assessment.20 A single randomized trial with FICE was negative.21
In Vivo Histologic Assessment
Accurate in vivo assessment of histology (Table 1) could play several clinically meaningful roles. First, removal of small distal colon hyperplastic polyps could be avoided, eliminating costs and risks. Second, small precancerous polyps could be resected and discarded without pathologic assessment. The resect and discard approach reduces pathology costs, and postpolypectomy surveillance colonoscopy intervals would be based on endoscopic assessment of histology. Finally, identification of cancer
Projections for the Future
The true prevalence of adenomas in the average-risk screening population is greater than 50%, as defined by high-level adenoma detectors.27, 28 These levels of detection probably can be achieved by any colonoscopist using modern bowel preparation methods and meticulous technique with white-light and HD colonoscopes. The greatest future gains in detection are likely to come via quality improvement programs that reduce variable performance with white-light colonoscopy. Thus, the potential gains
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Cited by (24)
Quality indicators for colonoscopy
2015, Gastrointestinal EndoscopyCitation Excerpt :Finally, technical adjuncts to imaging can be considered.179 Electronic chromoendoscopy (Olympus narrow-band imaging, Fujinon Intelligent Chromo Endoscopy, Pentax i-scan) has been ineffective in improving detection, but the investigators were typically endoscopists with high ADRs.179 One study suggested that narrow-band imaging induced a learning effect that improved white-light detection in endoscopists with low ADRs.180
Standard forward-viewing colonoscopy versus full-spectrum endoscopy: An international, multicentre, randomised, tandem colonoscopy trial
2014, The Lancet OncologyCitation Excerpt :Additionally, new colonoscope technologies have been tested for their ability to better detect flat or subtle lesions, or to improve visualisation of the mucosa behind colonic folds (eg, with cap-fitted or retroscopic colonoscopes) where adenomas might be hidden. Until now, these technological changes have been minimally effective or impractical for improvement of adenoma detection.29,30 Nowadays, standard forward-viewing colonoscopes visualise the colon from the flexible tip of the instrument, with an angle of view up to 170°.
Optimal withdrawal and examination in colonoscopy
2013, Gastroenterology Clinics of North AmericaManagement of small and diminutive polyps
2013, Techniques in Gastrointestinal EndoscopyQuality indicators for colorectal cancer screening for colonoscopy
2013, Techniques in Gastrointestinal EndoscopyCitation Excerpt :Both programs produced gains in polyp detection across the all endoscopists in their institutions. Finally, endoscopic technology, including chromoendoscopy, narrow band imaging and cap-fitted colonoscopy, may improve detection [113-116]. Endoscopists, regardless of specialty, who cannot improve their detection rates to reach recommended ADR thresholds through education and technical measures should have their colonoscopy privileges removed, as current evidence indicates that low-level detection may endanger patient care [11].
Conflicts of interest The author discloses the following: Dr Rex is on the speaker's bureau of Olympus America Inc and the scientific advisory board of Avantis Medical Systems.