Optivista : I-SCAN OE for Optical Diagnosis of Small Colon Polyps

The benefit of colonoscopy screening is based on the detection and removal of polyps neoplastic. However, the vast majority of found polyps do not harbor any risk of non-cancer neoplastic. The resection evaluation and histopathology of these polyps are associated with costs while the contribution to cancer prevention is limited. A new technique (Pentax Optivista) based on visual diagnosis of polyps has been introduced to reduce the costs associated with over-screening, and seems to be more efficient than the Pentax iScan technique. This research project aims to evaluate the new Optivista system compared to the iScan for his optical biopsy performance and interval agreement monitoring with pathology. This is a prospective clinical trial for which participants are recruited directly from the colonoscopy clinic. The Participants will be randomized to be diagnosed by either Optivista or Pentax iScan. Endoscope withdrawal will be done in iScan 1 mode for patients randomized to iSan and in Optivista OE2 mode for patients randomized to Optivista. For all polyps detected during the procedure, their size, location and morphology will be recorded according to the Paris classification after which all polyps will be resected per standard practices and sent for histopathologic evaluation. Polyps that are between 1-10mm in size (diminutive and small polyps), there will be further assessed according to WASP, NICE, SANO and SIMPLE classifications using white light imaging and using an image-enhancing endoscopy technology that enhances visualisation of the polyp surface and vascular patterns. Concordance between optical diagnosis and pathology monitoring according to recommendations will be presented as proportions with a 95% CI. The features optical polyp diagnostic test for overall diminutive (1-5mm) polyps and by location in the colon (proximal, distal, colon and rectosigmoid segments) will be presented. For outcome measures secondary factors, including factors that may influence the optical diagnosis, proportional estimates with a 95% confidence interval (CI) will be presented. Concordance between strategies is examined using a marginal homogeneity test (Stuart-Maxwell test). For the comparison of proportions, a chi square test or a Fisher's exact two-sided test will be used, as appropriate.