Seeing better - Evidence based recommendations on optimizing colonoscopy adenoma detection rate

Table 1 Techniques that have demonstrated improve adenoma detection rate

	Evidence	Limitations	Comments
Adequate bowel preparation	RCT and meta-analysis		Split-dose may have a positive impact itself on ADR
			No significant differences from fair to excellent bowel preparation
Withdrawal time	Retrospective	Some contradictory data, maybe reflecting that it is an intermediate parameter	Withdrawal time needs to be productively spent
			Likely more impact on low ADR endoscopists
Repeat right colon exploration or retroflexion	Prospective	Unclear if retroflexion preferable to forward view
Additional observers	Prospective	Heterogeneity in the type of observer	Marginal benefit, especially helpful if observers experienced
High definition endoscopy	RCT and one meta-analysis	Discrete effect for ADR, more significant for flat and right colonic lesions. Heterogeneity of the studies	ESGE recommends its use if available in average-risk screening colonoscopies
Position changes	Prospective, randomized	Unclear if the benefit is from seeing the colon segments twice
Water exchange	RCT	Slight impact on ADR	Most helpful to detect right colonic lesions
		Procedure time may confound results

ADR: Adenoma detection rate; ESGE: European Society of Gastrointestinal Endoscopy; RCT: Retrospective cohort study.

Table 2 Techniques with limited evidence favouring an increase in adenoma detection rate

	Evidence	Limitations	Comments
G-Eye	RCT	Only one RCT in progress	More studies are required
Endocuff	RCT		Not FDA approved
L-Menthol	RCT	Only one study	Further RCT required
		Not available in many countries out of Japan
Indigo carmine	RCT, prospective	Only two studies	Further RCT required.
		Withdrawal times confound results
AM procedures	Retrospective	Only two studies

RCT: Retrospective cohort study.

Table 3 Techniques that are unlikely to increase the adenoma detection rate

	Evidence	Limitations	Comments
NBI	RCT and meta-analysis tandem colonoscopy studies		There may be a role in improving ADR for new NBI generation
FICE (modes 3 and 4)	RCT including tandem colonoscopy studies
i-scan	RCT including tandem colonoscopy studies
Hyoscine	RCT and meta-analysis
Water-immersion	RCT
Rank-position	Prospective and retrospective	Only two studies
Cap	RCT and meta-analysis

NBI: Narrow-band imaging; ADR: Adenoma detection rate; RCT: Retrospective cohort study.