Endoscopic characterization of small colonic polyps: baseline performance of experienced endoscopists is no different to that of medical students

Precision endoscopy in colorectal polyps' characterization and planning of endoscopic therapy

Precision endoscopy in the management of colorectal polyps and early colorectal cancer has emerged as the standard of care. It includes optical characterization of polyps and estimation of submucosal invasion depth of large nonpedunculated colorectal polyps to select the appropriate endoscopic resection modality. Over time, several imaging modalities have been implemented in endoscopic practice to improve optical performance. Among these, image-enhanced endoscopy systems and magnification endoscopy represent now well-established tools. New advanced technologies, such as endocytoscopy and confocal laser endomicroscopy, have recently shown promising results in predicting the histology of colorectal polyps. In recent years, artificial intelligence has continued to enhance endoscopic performance in the characterization of colorectal polyps, overcoming the limitations of other imaging modes. In this review we retrace the path of precision endoscopy, analyzing the yield of various endoscopic imaging techniques in personalizing management of colorectal polyps and early colorectal cancer.

Mucosal imaging in colon polyps: New advances and what the future may hold

An expanding range of advanced mucosal imaging technologies have been developed with the goal of improving the detection and characterization of lesions in the gastrointestinal tract. Many technologies have targeted colorectal neoplasia given the potential for intervention prior to the development of invasive cancer in the setting of widespread surveillance programs. Improvement in adenoma detection reduces miss rates and prevents interval cancer development. Advanced imaging technologies aim to enhance detection without significantly increasing procedural time. Accurate polyp characterisation guides resection techniques for larger polyps, as well as providing the platform for the “resect and discard” and “do not resect” strategies for small and diminutive polyps. This review aims to collate and summarise the evidence regarding these technologies to guide colonoscopic practice in both interventional and non-interventional endoscopists.

Video clips compared with high-definition still images for characterization of colorectal neoplastic lesions: a randomized comparative prospective study

Background and study aims  Accurate real-time characterization of colorectal neoplastic lesions (CNLs) during colonoscopy is important for deciding appropriate treatment. No studies have evaluated whether still images or video clips are better for characterization. We compared histological predictions and size estimations of CNLs between two groups of gastroenterologists: one viewing still images and the other viewing video clips. Materials and methods  Participants were shown 20 CNLs as either 3-5 still images or a video clip. Three endoscopy experts obtained the images using high-definition white light and virtual chromoendoscopy without magnification. Stratified randomization was performed according to experience. For each lesion, participants assessed the size and histological subtype according to the CONECCT classification (hyperplastic polyp [IH], sessile serrated lesion [IS], adenoma [IIA], high-risk adenoma or superficial adenocarcinoma [IIC], or deeply invasive adenocarcinoma [III]). The correct histological status and size were defined by the pathology reports or combined criteria between histology and expert opinion for high-risk adenoma or superficial adenocarcinoma (CONECCT IIC). Results  332 participants were randomized and 233 performed the characterization. Participants comprised 118 residents, 75 gastroenterologists, and 40 endoscopy experts; 47.6 % were shown still images and 52.4 % viewed video clips. There was no statistically significant difference between the two groups in histological prediction, our primary end point. However, the lesion size was better assessed using still images than video clips ( P  = 0.03). Conclusions  Video clips did not improve the histological prediction of CNLs compared with still images. Size was better assessed using still images.

Training methods in optical diagnosis and characterization of colorectal polyps: a systematic review and meta-analysis

Background and study aims  Correct optical diagnosis of colorectal polyps is crucial to implement a resect and discard strategy. Training methods have been proposed to reach recommended optical diagnosis thresholds. The aim of our study was to present a systematic review and meta-analysis on optical diagnosis training. Methods  PubMed/Medline and Cochrane databases were searched between 1980 and October 2019 for studies reporting outcomes on optical diagnosis training of colorectal polyps. The primary outcome was optical diagnosis accuracy compared to histological analysis pre-training and post-training intervention. Subgroup analyses of experienced/trainee endoscopists, training methods, and small/diminutive polyps were included. Results  Overall, 16 studies met inclusion criteria, analyzing the impact of training on 179 endoscopists. Pre-training accuracy was 70.3 % (6416/9131 correct diagnoses) whereas post-training accuracy was 81.6 % (7416/9213 correct diagnoses) (risk ratio [RR] 1.17; 95 % confidence interval [CI]: 1.09-1.24, P  < 0.001). In experienced endoscopists, accuracy improved from 69.8 % (3771/5403 correct diagnoses) to 82.4 % (4521/5485 correct diagnoses) (RR 1.20; 95 % CI: 1.11-1.29, P  < 0.001). Among trainees, accuracy improved from 69.6 % (2645/3803 correct diagnoses) to 78.8 % (2995/3803 correct diagnoses) (RR 1.14; 95 % CI 1.06-1.24, P  < 0.001). In the small/diminutive polyp subgroup, accuracy improved from 68.1 % (3549/5214 correct diagnoses) to 77.1 % (4022/5214 correct diagnoses) in (RR 1.16 95 % CI 1.08-1.24 P  < 0.001). On meta-regression analysis, the improvement in accuracy did not differ between computerized vs. didactic training approaches for experienced ( P  = 0.792) and trainee endoscopists ( P  = 0.312). Conclusions  Optical diagnosis training is effective in improving accuracy of histology prediction in colorectal polyps. Didactic and computer-based training show comparable effectiveness in improving diagnostic accuracy.