Background/Aims: Colorectal polyps are removed to prevent progression to colorectal cancer. Polyp size is an important factor for risk stratification of malignant transformation. Endoscopic size estimation correlates poorly with pathological reports and several factors have been suggested to influence size estimation. We aimed to gain insight into the factors influencing endoscopic polyp size estimation. Methods: Images of polyps in an artificial model were obtained at 1, 3, and 5 cm from the colonoscope’s tip. Participants were asked to estimate the diameter and volume of each polyp. Results: Fifteen endoscopists from three large-volume centers participated in this study. With an intraclass correlation coefficient of 0.66 (95% confidence interval [CI], 0.62–0.71) for diameter and 0.56 (95% CI, 0.50–0.62) for volume. Polyp size estimated at 3 cm from the colonoscope’s tip yielded the best results. A lower distance between the tip and the polyp was associated with a larger estimated polyp size. Conclusions Correct endoscopic estimation of polyp size remains challenging. This finding can affect size estimation skills and future training programs for endoscopists.

Background/Aims: We aimed to study the effects of sedation on endoscopic ultrasound–guided tissue acquisition. Methods: We conducted a retrospective study evaluating the role of sedation in endoscopic ultrasound–guided tissue acquisition by comparing two groups: anesthesia care provider (ACP) sedation and endoscopist-directed conscious sedation (CS). Results: Technical success was achieved in 219/233 (94.0%) in the ACP group and 114/136 (83.8%) in the CS group (p=0.0086). In multivariate analysis, the difference in technical success between the two groups was not significant (adjusted odds ratio [aOR], 0.5; 95% confidence interval [CI], 0.234–1.069; p=0.0738). A successful diagnostic yield was present in 146/196 (74.5%) in the ACP group and 66/106 (62.3%) in the CS group, respectively (p=0.0274). In multivariate analysis, the difference in diagnostic yield between the two groups was not significant (aOR, 0.643; 95% CI, 0.356–1.159; p=0.142). A total of 33 adverse events (AEs) were observed. The incidence of AEs was significantly lower in the CS group (5/33 CS vs. 28/33 ACP; OR, 0.281; 95% CI, 0.095–0.833; p=0.022). Conclusions CS provided equivalent technical success and diagnostic yield for malignancy in endoscopic ultrasound–guided tissue acquisition. Increased AEs were associated with anesthesia for the endoscopic ultrasound–guided tissue acquisition.

Background/Aims: Endoscopic diagnosis of dysplasia or colitic cancer in patients with ulcerative colitis (UC) is more challenging than that of colorectal neoplasia in non-colitic patients. We aimed to evaluate the accuracy of the endo-scopic diagnosis of “nonpedunculated” dysplasia or colitic cancer in UC patients. Methods: Ten endoscopists from four countries were surveyed using photographs of 61 histologi-cally confirmed dysplastic or non-dysplastic lesions retrieved from the UC registry database of Asan Medical Center. The participants provided their assessment based on the given photographs and their intention to perform biopsy. Results: The overall diagnostic performance of the 10 participants is summarized as follows: sensitivity of 88.2% (95% confidence interval [CI], 84.3% to 91.5%), specificity of 34.8% (95% CI, 29.1% to 40.8%), positive predictive value of 63.0% (95% CI, 60.8% to 65.2%), negative predictive value of 70.2% (95% CI, 62.7% to 76.6%), and accuracy of 64.6% (95% CI, 60.7% to 68.4%). The interobserver agreement on the inten-tion to perform a biopsy was poor (Fleiss kappa=0.169). Of the three endoscopic characteristics of the lesions, includ-ing ulceration, distinctness of the borders, and pit patterns, only neoplastic pit patterns were significantly predictive of dysplasia (odds ratio, 3.710; 95% CI, 2.001 to 6.881). The diagnostic sensitivity and specificity of neoplastic pit patterns were 68.2% (95% CI, 63.0% to 73.2%) and 63.3% (95% CI,57.3% to 69.1%), respectively. Conclusions Diagnostic per-formance based on the endoscopist’s intention to perform a biopsy for nonpedunculated potentially dysplastic lesions in UC patients was suboptimal according to this survey-based study.