To discuss the rationale for the widespread application of endoscopic mucosal resection (EMR) rather than endoscopic submucosal dissection (ESD) in Western centers. In Western centers, EMR is the treatment of choice for most non-pedunculated colorectal adenomas >2 cm in size. EMR is sufficiently effective and safe to be performed without post-procedure hospitalization. Advances in EMR have led to reduced recurrence rates, and recent studies have demonstrated excellent outcomes with endoscopic treatment of recurrent adenomas. While studies from Asia have demonstrated lower recurrence rates with ESD, concern about the higher perforation risk and lengthy procedure time of ESD are two of the barriers preventing widespread adoption of ESD in the West. EMR is likely to continue as the dominant method for the treatment of large colorectal adenomas in Western centers until the limitations of ESD are overcome.
Adenoma ; Asia ; Colonic Polyps ; Colonoscopy ; Colorectal Neoplasms ; Hospitalization ; Methods ; Polyps* ; Recurrence

While perforations, postoperative fistulas, and leaks have traditionally led to surgical or interventional radiology consultation for management, the introduction of the over-the-scope clip has allowed increased therapeutic possibilities for endoscopists. While primarily limited to case reports and series, the over-the-scope clip successfully manages gastrointestinal bleeding, perforations, as well as postoperative leaks and fistulas. Retrospective studies have demonstrated a relatively high success rate and a low complication rate. Given the similarity to variceal banding equipment, the learning curve with the over-the-scope clip is rapid. However, given the higher risk of procedures involving the use of the over-the-scope clip, it is essential to obtain the scope in a stable position and grasp sufficient tissue with the cap using a grasping tool and/or suction. From our experience, while closure may be successful in lesions sized up to 3 cm, successful outcomes are obtained for lesions sized <1 cm. Ultimately, given the limited available data, prospective randomized trials are needed to better evaluate the utility of the over-the-scope clip in various clinical scenarios, including fistula and perforation management.

Background/Aims: Cold snare polypectomy (CSP) is an effective method of polyp removal for small colorectal polyps. However, the effect of submucosal injection in cold snare endoscopic mucosal resection (CS-EMR) for small polyps is unclear. Therefore, this study aimed to evaluate the effect of submucosal injection in CS-EMR for small polyps. Methods: Between 2018 and 2019, 100 consecutive small colorectal polyps (5–10 mm) were identified in 58 patients. The first 50 consecutive polyps were removed by CS-EMR, and the remaining 50 were removed by CSP. Demographic data, clinical data, endoscopic findings, procedure times, complication rates, and pathology data were collected. Results: No difference in the complete resection rate was observed between the CS-EMR and CSP groups. A total of 9 polyps showed post-polypectomy bleeding (7 had immediate bleeding, 1 had delayed bleeding, and 1 had both immediate and delayed bleeding). No difference in the bleeding rate was observed between the two groups. In multivariate analysis, warfarin (odds ratio [OR], 42.334; 95% confidence interval [CI], 1.006–1,781.758) and direct-acting oral anticoagulants (OR, 35.244; 95% CI, 3.853–322.397) showed a significantly increased risk of bleeding. Conclusions The effect of submucosal injection in CSP was not significant for small colorectal polyps.

Background/Aims: Cold snare polypectomy (CSP) is an effective method of polyp removal for small colorectal polyps. However, the effect of submucosal injection in cold snare endoscopic mucosal resection (CS-EMR) for small polyps is unclear. Therefore, this study aimed to evaluate the effect of submucosal injection in CS-EMR for small polyps. Methods: Between 2018 and 2019, 100 consecutive small colorectal polyps (5–10 mm) were identified in 58 patients. The first 50 consecutive polyps were removed by CS-EMR, and the remaining 50 were removed by CSP. Demographic data, clinical data, endoscopic findings, procedure times, complication rates, and pathology data were collected. Results: No difference in the complete resection rate was observed between the CS-EMR and CSP groups. A total of 9 polyps showed post-polypectomy bleeding (7 had immediate bleeding, 1 had delayed bleeding, and 1 had both immediate and delayed bleeding). No difference in the bleeding rate was observed between the two groups. In multivariate analysis, warfarin (odds ratio [OR], 42.334; 95% confidence interval [CI], 1.006–1,781.758) and direct-acting oral anticoagulants (OR, 35.244; 95% CI, 3.853–322.397) showed a significantly increased risk of bleeding. Conclusions The effect of submucosal injection in CSP was not significant for small colorectal polyps.

BACKGROUND/AIMS: Endoscopic mucosal resection with circumferential mucosal incision (CMI-EMR) may offer benefits comparable to those of endoscopic submucosal dissection (ESD), while requiring less technical proficiency than ESD. METHODS: We retrospectively compared the outcomes of CMI-EMR (n=34) and size-matched ESD (n=102), which were performed by a Korean endoscopist for colorectal epithelial lesions of 20–35 mm. Procedural parameters of CMI-EMRs performed by an American ESD novice (n=30) were compared with those performed by the Korean endoscopist. RESULTS: The lesion size was 22.3±3.9 mm and 22.9±2.4 mm in the CMI-EMR and size-matched ESD groups, respectively (p=0.730). The resection time was 12.7±7.0 minutes in the CMI-EMR group and 45.6±30.1 minutes in the ESD group (p<0.001). The en bloc resection rate was 94.1% in the CMI-EMR group and 100% in the ESD group (p=0.061). There were no differences in the en bloc resection and complication rates of CMI-EMRs between a Korean and an American endoscopist. CONCLUSIONS: For the treatment of moderate-size colorectal lesions, CMI-EMR showed a trend toward lower en bloc resection rate, but required shorter procedure time than ESD. CMI-EMR outcomes were similar when performed by a Korean ESD expert and an American ESD novice.
Colon ; Colorectal Neoplasms* ; Rectum ; Retrospective Studies

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.