Endoscopic innovations to increase the adenoma detection rate during colonoscopy

Table 1 Endoscopic innovations to improve the adenoma detection during colonoscopy

Technique	Colonoscopy technology	Diagnostic yield	Clinical applicability
High definition	High definition monitor with more images per second and high resolution	Marginal increase in number of polyps and adenomas, mostly small, flat, right-sided lesions. approximation 3.5% increase in ADR	High quality images with reduced artifacts and more natural appearance
Narrow band imaging (NBI)	Narrow band filters increase blue (415 nm) and green (540 nm) wavelengths and enhance the visualization of mucosal blood vessels	Small increase in flat and small serrated lesions, but higher detection rates when combined with high definition	Possibly improving the detection of subtle lesions, but insufficient brightness and dark appearing bile and stool prohibit optimal pan-colonic use
Fujinon intelligent color enhancement	Computed spectral estimation technology enhances the visibility of mucosal and vascular details by narrowing the bandwidth of light	Very few randomized studies but polyp and adenoma detection seems similar compared to white light colonoscopy	Like with NBI, images are to dark to advice routine pan-colonic use
Autofluorescence imaging (AFI)	Tissue is exposured to light of short wavelength, which leads to the excitation of endogenous substances and the emission of autofluorescent light	AFI has lower adenoma miss rates (absolute difference of approximation 20%) when compared to white light colonoscopy, especially for flat and depressed lesions	Not advised for routine practice in colonoscopy due to low resolution images, few images per second and artifacts due to residual fecal fluids
Water-immersion colonoscopy	Infusion of water, combinated with air-insufflation, during insertion of the colonoscope. Water and remaining fecal content are removed during withdrawal	No difference in ADR between water-immersion and air-insufflated colonoscopy	Reduces pain scores, need for sedation and general intolerability, but only studied in highly experienced hands
Water-exchange colonoscopy	Water containing residual feces is removed and “exchanged” for clean water during insertion in lieu of air-insufflation	ADR is reported to be approximation 10% higher with water-exchange colonoscopy compared to standard air-insufflated colonoscopy	Provides extra cleansing of the mucosa but is more time consuming and is thus far only studied in highly experienced hands
Cap-assisted colonoscopy	Can be used to depress colonic folds to improve the visualization of proximal aspects of these folds	Contradicting results with approximation 10% higher detection rates for small polyps and adenomas in some studies, but no beneficial results in others	Easy to use, can assist during mucosectomies and facilitates introduction of the colonoscope, but probably has a limited effect on diagnostic yield
Retroflexion	Withdrawal in retroflexion is possible in the proximal colon due to the large diameter of this segment and may improve the visualization of the proximal aspects of folds	No additional diagnostic yield in the proximal colon and questionable in the rectum	Routine withdrawal in retroflexion is not recommended but may facilitate the removal of large sessile polyps
Third-eye retroscope	The retroscope is retroflexed 180 degrees after being advanced through the working channel and enhances the visualization behind folds	Limited number of studies, but polyp and adenoma detection are reported to be 15%-25% higher compared to standard colonoscopy	Increases diagnostic yield, but reduces suctioning capacity when in position and needs to be removed from working channel in case of polypectomy
Full spectrum endoscopy (FUSE)	Three imagers positioned at the front and both sides of the tip provide a 330 degrees view, which improve the visualization of the internal lining of flexures and proximal aspects of folds	One randomized tandem study thus far, which showed considerably lower miss rates for polyps (9.7% vs 43.%) and adenomas (7.5% vs 40.8%) compared to standard colonoscopy	Provides a comprehensive view while maintaining technical capabilities of standard colonoscopes. Requires little training

ADR: Adenoma detection rate.