A novel colonoscope with extra-wide field of view optics increases polyp detection rates compared to the standard instrument: Results from a prospective model-based trial

Aims Colonoscopy is considered the gold standard for colorectal cancer screening but lesions can be missed, resulting in interval cancers in a significant number of patients. Polyps hidden behind haustral folds or in tight flexures are particularly difficult to visualize with current forward-viewing instruments. This prospective study evaluated lesion detection rate and performance of a novel colonoscope with 230-degree (partially retrograde) extra-wide field of view compared to the standard 170-degree colonoscope in a colon model.

Methods A 3D-printed silicon model of a colon was specifically commissioned for this study from Lazarus 3D, Albany, OR. The model has a length of 62cm, simulates ascending, transverse and descending colon segments, and includes 12 sessile polyps between 4mm and 7.5mm in size, placed throughout the colon, with several polyps located on the proximal side of haustral folds. Endoscopist were recruited during a GI conference and instructed to perform back-to-back examinations of the colon model, first inserting a standard colonoscope (SC; EC38-i20cL, 170- degree forward-viewing optics, Pentax Medical) immediately followed by a second exam using the new 230-degree extra-wide field of view colonoscope (EFOV; EC38-i20cLW, Pentax Medical). Participants were instructed to identify polyps during a timed 4-minute withdrawal and to then place a snare around the most distal polyp. A standardized survey was used to record the operator's impression of endoscope/snare handling, optical performance and maneuverability, using a 5-point Likert scale for all assessments.

Results Twenty-nine experienced endoscopists participated in this trial; 90% of them had performed>1000 colonoscopies during their careers. Using the standard colonoscope, an average of 5.3 polyps were detected, compared to 9.6 polyps when using the EFOV colonoscope (p<0.001). The median difference in the number of polyps detected by the same endoscopist between SC and EFOV was 4; range 1-8 (p-value of Wilcoxon signed-rank test:<0.001). Five of 29 (17.2%) operators detected all 12 polyps with the EFOV scope, while no operator detected all polyps with the SC. The success rate of placing a snare was 100% for both endoscopes with similar timings (mean of 14 sec vs 15 sec for SC and EFOV, respectively). The handling, optical performance and maneuverability of the EFOV colonoscope compared to the SC was rated as equally good or better by all endoscopists.

Conclusions Use of a novel colonoscope with a 230-degree (partially retrograde) extra-wide field of view resulted in a significant improvement in polyp detection rates compared to a standard colonoscope in this non-randomized model-based trial, with favorable performance and usability ratings for the EFOV instrument. Clinical studies are required to confirm these encouraging preliminary results.

Publication History

Article published online:
15 April 2024