High-definition with i-Scan gives comparable accuracy for detecting colonic lesions by non-expert and expert endoscopists.

Background: Lesion detection rate during colonoscopy may be influenced by the endoscopist's experience. EPK-i system colonoscopy (i-Scan) can improve mucosal and vascular visualization for detecting lesions.

Aim: To compare mucosal lesions detection rate and the withdrawal time of the instrument among non-expert and expert endoscopists.

Methods: Colonoscopy records of all consecutive patients undergoing first HD+ with i-Scan- or SWL-equipped colonoscopy for colorectal cancer screening over a twelve-month period were evaluated, in a "post hoc" analysis.

Results: 542 colonoscopies (389 HD+ with i-Scan; 153 SWL): expert and non-expert endoscopists did respectively 272 and 117 HD+ with i-Scan and 83 and 70 SWL colonoscopies. Expert endoscopists did more i-Scan colonoscopies than non-experts (p=0.006). In the SWL procedures, the experts detected mucosal lesions in more colonoscopies than non-experts (61/22 vs. 23/47, p=0.0001) and found a significantly higher mean number of lesions (1.34 vs. 0.47; p=0.0001). Experts detected more or less the same mean number of lesions with both imaging techniques, while among non-experts detection with HD+ with i-Scan was significantly better than with SWL imaging (1.39 vs. 0.47; p=0.0001).

Conclusions: HD+ with i-Scan imaging enables less skilled endoscopists to achieve results comparable to those of experienced ones in detecting mucosal lesions.