Non-pedunculated Polyps Research Articles

Cold versus hot snare endoscopic mucosal resection for large (≥15 mm) flat non-pedunculated colorectal polyps: a randomised controlled trial

Background and aimsConventional hot snare endoscopic mucosal resection (H-EMR) is effective for the management of large (≥20 mm) non-pedunculated colon polyps (LNPCPs) however, electrocautery-related complications may incur significant morbidity. With...

Impact of margin thermal ablation after endoscopic mucosal resection of large (≥20 mm) non-pedunculated colonic polyps on long-term recurrence

Background and aimsThe efficacy of colorectal endoscopic mucosal resection (EMR) is limited by recurrence and the necessity for conservative surveillance. Margin thermal ablation (MTA) after EMR has reduced the incidence...

The Use of Clips to Prevent Post-Polypectomy Bleeding: A Clinical Review.

The goal of this clinical review is to provide an overview of the current literature regarding the utility of prophylactic clips in reducing postpolypectomy bleeding and to provide an expert statement regarding their appropriateness in clinical practice. Colonoscopy enables the identification and removal of premalignant and malignant lesions through polypectomy, yet complications including postpolypectomy bleeding (PPB) can arise. While various studies have explored applying clips prophylactically to prevent PPB, their effectiveness remains uncertain. A literature search conducted in PubMed and Embase identified 671 publications discussing clip use postpolypectomy; 67 were found to be relevant after screening, reporting outcomes related to PPB. Data related to clip utilization, polyp characteristics, and adverse events were extracted and discussed. The current literature suggests that prophylactic clipping is most beneficial for nonpedunculated polyps ≥20mm, especially those in the proximal colon. The utility of clipping smaller polyps and those in the distal colon remains less clear. Antithrombotic medication usage, particularly anticoagulants, has been linked to an increased risk of bleeding, prompting consideration for clip placement in this patient subgroup. While cost-effectiveness analyses may indicate potential savings, the decision to clip should be tailored to individual patient factors and polyp characteristics. Current research suggests that the application of prophylactic clips can be particularly beneficial in preventing delayed bleeding after removal of large nonpedunculated polyps, especially for those in the proximal colon and in patients on antithrombotic medications. In addition, for large pedunculated polyps prophylactic clipping is most effective at controlling immediate bleeding.

Prevalence of Endoscopically Curable Low-Risk Cancer Among Large (≥20 mm) Nonpedunculated Polyps in the Right Colon

Background and aimsEndoscopic submucosal dissection (ESD) is increasingly promoted for the treatment of all large non-pedunculated colorectal polyps (LNPCP), to cure potential low-risk cancers (superficial submucosal invasion without additional high-risk histopathological features). The effect of a universal en bloc strategy on oncological outcomes for the treatment of LNPCP in the right colon is unknown. We evaluated this in a large Western population. MethodsA prospective cohort of patients referred for endoscopic resection (ER) of LNPCP was analysed. Patients found to have cancer after ER and those referred directly to surgery were included. The primary outcome was to determine the proportion of right colon LNPCP with low-risk cancer. ResultsOver 180 months until June 2023, 3294 sporadic right colon LNPCP in 2956 patients were referred for ER at 7 sites (median size 30mm [IQR 15]). 63 (2.1%) patients were referred directly to surgery and cancer was proven in 56 (88.9%). 2851/2956 (96.4%) LNPCP underwent ER (median size 35mm [IQR 20]) of which 75 (2.6%) were cancers. The overall prevalence of cancer in the right colon was 4.4% (131/2956). Detailed histopathological analysis was possible in 115/131 (88%) cancers (71 after ER, 44 direct to surgery). After excluding missing histopathological data, 23/2940 (0.78%) sporadic right colon LNPCP were low-risk cancers. ConclusionsThe proportion of right colon LNPCP referred for ER containing low-risk cancer amenable to endoscopic cure was <1%, in a large, multicentre Western cohort. A universal ESD strategy for the management of right colon LNPCP is unlikely to yield improved patient outcomes given the minimal impact on oncological outcomes. Clinical TrialAustralian Colonic Endoscopic Resection (ACE) cohort: NCT01368289 (https://classic.clinicaltrials.gov/ct2/show/NCT01368289); NCT02000141 (https://classic.clinicaltrials.gov/ct2/show/NCT02000141)

Long-term adenoma recurrence and development of colorectal cancer following endoscopic mucosal resection in large non-pedunculated colonic polyps ≥4 cm

ObjectivesData of long-term follow up for large non pedunculated colorectal polyps (LNPCPs) ≥4 cm removed with piecemeal wide field endoscopic mucosal resection (PWF-EMR) are limited. We primarily evaluated the recurrence rates and secondarily the rates of post colonoscopic polypectomy colorectal cancer (PCPCRC) on a long-term basis. MethodsWe retrospectively reviewed a prospectively-stored electronic database of all patients who underwent PWF-EMR for LNPCPs at the Venizeleion General Hospital, between 2009 and 2020. Eligible patients were those with LNPCPs ≥4 cm, deemed completely removed by endoscopic means and followed-up for a minimum of 36 months with at least two surveillance colonoscopies, the first one (SC1) (4–6) months after the initial PWF-EMR procedure and the second one (SC2) after (12–18) months. In 2023, all cases were checked for PCPCRC development. ResultsResidual/early recurrent tissue was detected in 44 (31 %) cases among the 142 (82 males, 60 females) assessed during SC1. Late recurrent tissue was detected in 9 (6.6 %) cases among the 137 surveyed during SC2. Investigation did not reveal any case of PCPCRC . ConclusionsThis historical cohort shows that the PWF-EMR for LNPCPs ≥4 cm is a safe and definitive removal method while it is not associated with the appearance of PCPCRC.

Effect of optical diagnosis training on recognition and treatment of submucosal invasive colorectal cancer in community hospitals: a prospective multicenter intervention study.

Recognition of submucosal invasive colorectal cancer (T1 CRC) is difficult, with sensitivities of 35 %-60 % in Western countries. We evaluated the real-life effects of training in the OPTICAL model, a recently developed structured and validated prediction model, in Dutch community hospitals. In this prospective multicenter study (OPTICAL II), 383 endoscopists from 40 hospitals were invited to follow an e-learning program on the OPTICAL model, to increase sensitivity in detecting T1 CRC in nonpedunculated polyps. Real-life recognition of T1 CRC was then evaluated in 25 hospitals. Endoscopic and pathologic reports of T1 CRCs detected during the next year were collected retrospectively, with endoscopists unaware of this evaluation. Sensitivity for T1 CRC recognition, R0 resection rate, and treatment modality were compared for trained vs. untrained endoscopists. 1 year after e-learning, 528 nonpedunculated T1 CRCs were recorded for endoscopies performed by 251 endoscopists (118 [47 %] trained). Median T1 CRC size was 20 mm. Lesions were mainly located in the distal colorectum (66 %). Trained endoscopists recognized T1 CRCs more frequently than untrained endoscopists (sensitivity 74 % vs. 62 %; mixed model analysis odds ratio [OR] 2.90, 95 %CI 1.54-5.45). R0 resection rate was higher for T1 CRCs detected by trained endoscopists (69 % vs. 56 %; OR 1.73, 95 %CI 1.03-2.91). Training in optical recognition of T1 CRCs in community hospitals was associated with increased recognition of T1 CRCs, leading to higher en bloc and R0 resection rates. This may be an important step toward more organ-preserving strategies.

Safety and efficacy of low-power pure-cut hot snare polypectomy for small nonpedunculated colorectal polyps compared with conventional resection methods: A propensity score matching analysis.

Cold snare polypectomy (CSP) is widely performed for small colorectal polyps. However, small colorectal polyps sometimes include high-grade adenomas or carcinomas that require endoscopic resection with electrocautery. This study aimed to evaluate the efficacy and safety of a novel resection technique, hot snare polypectomy with low-power pure-cut current (LPPC-HSP) for small colorectal polyps, compared with CSP and conventional endoscopic mucosal resection (EMR). Records of patients who underwent CSP, EMR, or LPPC-HSP for nonpedunculated colorectal polyps less than 10 mm between April 2021 and March 2022 were retrospectively evaluated. We analyzed and compared the treatment outcomes of CSP and EMR with those of LPPC-HSP using propensity score matching. After propensity score matching of 396 pairs, an analysis of CSP and LPPC-HSP indicated that LPPC-HSP had a significantly higher R0 resection rate (84% vs. 68%; p < 0.01). Delayed bleeding was observed in only two cases treated with CSP before matching. Perforation was not observed with either treatment. After propensity score matching of 176 pairs, an analysis of EMR and LPPC-HSP indicated that their en bloc and R0 resection rates were not significantly different (99.4% vs. 100%, p = 1.00; 79% vs. 81%, p = 0.79). Delayed bleeding and perforation were not observed with either treatment. The safety of LPPC-HSP was comparable to that of CSP. The treatment outcomes of LPPC-HSP were comparable to those of conventional EMR for small polyps. These results suggest that this technique is a safe and effective treatment for nonpedunculated polyps less than 10 mm.

Colorectal polypectomy and endoscopic mucosal resection: European Society of Gastrointestinal Endoscopy (ESGE) Guideline - Update 2024.

1: ESGE recommends cold snare polypectomy (CSP), to include a clear margin of normal tissue (1-2 mm) surrounding the polyp, for the removal of diminutive polyps (≤ 5 mm).Strong recommendation, high quality of evidence. 2: ESGE recommends against the use of cold biopsy forceps excision because of its high rate of incomplete resection.Strong recommendation, moderate quality of evidence. 3: ESGE recommends CSP, to include a clear margin of normal tissue (1-2 mm) surrounding the polyp, for the removal of small polyps (6-9 mm).Strong recommendation, high quality of evidence. 4: ESGE recommends hot snare polypectomy for the removal of nonpedunculated adenomatous polyps of 10-19 mm in size.Strong recommendation, high quality of evidence. 5: ESGE recommends conventional (diathermy-based) endoscopic mucosal resection (EMR) for large (≥ 20 mm) nonpedunculated adenomatous polyps (LNPCPs).Strong recommendation, high quality of evidence. 6: ESGE suggests that underwater EMR can be considered an alternative to conventional hot EMR for the treatment of adenomatous LNPCPs.Weak recommendation, moderate quality of evidence. 7: Endoscopic submucosal dissection (ESD) may also be suggested as an alternative for removal of LNPCPs of ≥ 20 mm in selected cases and in high-volume centers.Weak recommendation, low quality evidence. 8: ESGE recommends that, after piecemeal EMR of LNPCPs by hot snare, the resection margins should be treated by thermal ablation using snare-tip soft coagulation to prevent adenoma recurrence.Strong recommendation, high quality of evidence. 9: ESGE recommends (piecemeal) cold snare polypectomy or cold EMR for SSLs of all sizes without suspected dysplasia.Strong recommendation, moderate quality of evidence. 10: ESGE recommends prophylactic endoscopic clip closure of the mucosal defect after EMR of LNPCPs in the right colon to reduce to reduce the risk of delayed bleeding.Strong recommendation, high quality of evidence. 11: ESGE recommends that en bloc resection techniques, such as en bloc EMR, ESD, endoscopic intermuscular dissection, endoscopic full-thickness resection, or surgery should be the techniques of choice in cases with suspected superficial invasive carcinoma, which otherwise cannot be removed en bloc by standard polypectomy or EMR.Strong recommendation, moderate quality of evidence.

Cold endoscopic mucosal resection versus cold snare polypectomy for colorectal lesions: a systematic review and meta-analysis of randomized controlled trials.

Cold resection of colorectal lesions is widely performed because of its safety and effectiveness; however, it remains uncertain whether adding submucosal injection could improve the efficacy and safety. We aimed to compare cold endoscopic mucosal resection (C-EMR) versus cold snare polypectomy (CSP) for colorectal lesions. We performed a systematic review of randomized controlled trials (RCTs) identified from PubMed, Cochrane Library, and Embase. The primary outcome was complete resection. Secondary outcomes were procedure time, en bloc resection, and adverse events (AEs). Prespecified subgroup analyses based on the size and morphology of the polyps were performed. The random-effects model was used to calculate the pooled risk ratio (RR) and mean difference, with corresponding 95%CIs, for dichotomous and continuous variables, respectively. Heterogeneity was assessed using the Cochran Q test and I 2 statistics. 7 RCTs were included, comprising 1556 patients, with 2287 polyps analyzed. C-EMR and CSP had similar risk ratios for complete resection (RR 1.02, 95%CI 0.98-1.07), en bloc resection (RR 1.08, 95%CI 0.82-1.41), and AEs (RR 0.74, 95%CI 0.41-1.32). C-EMR had a longer procedure time (mean difference 42.1 seconds, 95%CI 14.5-69.7 seconds). In stratified subgroup analyses, the risk was not statistically different between C-EMR and CSP for complete resection in polyps<10 mm or ≥10 mm, or for complete resection, en bloc resection, and AEs in the two groups among nonpedunculated polyps. The findings of this meta-analysis suggest that C-EMR has similar efficacy and safety to CSP, but significantly increases the procedure time. CRD42023439605.

A132 A COLON-SPECIFIC SELECTIVE RESECTION ALGORITHM FOR LARGE NON-PEDUNCULATED POLYPS OPTIMIZES EFFICIENCY WITH HIGH TECHNICAL AND CLINICAL SUCCESS: A PROSPECTIVE COHORT STUDY

Abstract Background Endoscopic resection is now the first line treatment strategy for most large (≥20 mm) non-pedunculated colonic polyps (LNPCPs); which includes endoscopic mucosal resection (EMR), cold snare resection (CSR), and endoscopic submucosal dissection (ESD). A selective resection algorithm incorporating EMR and ESD is cost effective and optimizes oncologic outcomes in the rectum. However, a focused evaluation for colonic lesions has not been described. Aims Assess the performance of a colon-specific selective resection algorithm for LNPCPs. Methods Consecutive patients ampersand:003E 18 years of age who underwent endoscopic resection for a LNPCP were enrolled in a prospective single center observation cohort study (clinicaltrials.gov ID: NCT05402696). Modality selection was determined by optical evaluation using the Paris and the Japan NBI Expert Team (JNET) classifications: 1) JNET I – CSR; 2) JNET IIA – EMR; 3) JNET IIB or Paris 0-IIC morphology – en bloc resection (EMR/ESD); 4) JNET III – referral to surgery/multi-disciplinary team review. Algorithm performance was evaluated by technical success (all neoplastic tissue removed at index procedure), procedure-related adverse events, referral to surgery, and recurrence at first surveillance colonoscopy (SC1). Results From 06/2022-09/2023, 230 patients underwent 244 procedures for 295 lesions. Median age was 67 years (IQR 61-74 years) and 127 (55.2%) were male. Median lesion size was 30mm (IQR 20-40mm). Cancer was identified in 12 (4.1%) LNPCPs. Based on pre-resection optical evaluation, 204 (69.2%), 86 (29.2%) and 5 (1.7%) LNPCPs underwent EMR, CSR and ESD, respectively. Technical success was 97.1%, 100.0% and 100.0% for EMR, CSR and ESD, respectively (p=0.245). Procedure duration was significantly shorter for CSR (10 min; IQR 8-15 min) compared to EMR (15 min; IQR 10-25 min) and ESD (30 min; IQR 30-60 min) (P ampersand:003C 0.001). There was no significant difference in intra-procedural perforation, clinically significant post-endoscopic resection bleeding, delayed perforation or serositis, with overall frequencies of 3.4%, 5.2%, 0% and 0.4% respectively. Surgery was performed for 15 lesions (11 submucosal invasive cancer (SMIC); 3 synchronous SMIC; 1 technical failure). Of LNPCPs completing SC1, there was 1 recurrence (1.2%) in the CSR group (p=0.366), which was successfully managed endoscopically. Conclusions A colon-specific selective resection algorithm optimizes procedural efficiency and the risk-benefit profiles of EMR, CSR and ESD for LNPCPs. Funding Agencies None

Establishment of standards for the referral of large nonpedunculated colorectal polyps: an international expert consensus using a modified Delphi process

Resection of colorectal polyps has been shown to decrease the incidence and mortality of colorectal cancer. Large nonpedunculated colorectal polyps are often referred to expert centers for endoscopic resection, which requires relevant information to be conveyed to the therapeutic endoscopist to allow for triage and planning of resection technique. The primary objective of this study was to establish minimum expected standards for the referral of large nonpedunculated colonic polyps for potential endoscopic resection. A Delphi method was used to establish consensus on minimum expected standards for the referral of large colorectal polyps among a panel of international endoscopy experts. The expert panel was recruited through purposive sampling, and 3 rounds of surveys were conducted to achieve consensus. Quantitative and qualitative data were analyzed for each round. A total of 24 international experts from diverse continents participated in the Delphi study, resulting in consensus on 19 statements related to the referral of large colorectal polyps. The identified factors, including patient demographic characteristics, relevant medications, lesion factors, photodocumentation, and the presence of a tattoo, were deemed important for conveying the necessary information to therapeutic endoscopists. The mean scores for the statements, which were scored on a scale of 1 to 10, ranged from 7.04 to 9.29, with high percentages of experts considering most statements as a very high priority. Subgroup analysis according to continent revealed some variations in consensus rates among experts from different regions. The identified consensus statements can aid in improving the triage and planning of resection techniques for large colorectal polyps, ultimately contributing to the reduction of colorectal cancer incidence and mortality.

P1065 Endoscopic Submucosal Dissection for High-Risk Colorectal Colitis-Associated Neoplasia in Inflammatory Bowel Disease: a Real-World Multicenter Study

Abstract Background Inflammatory bowel disease (IBD) patients have a 2-3-fold increased risk of developing colorectal cancer. High-risk colorectal colitis-associated neoplasia (HR-CAN), including non-polypoid lesions and large non-pedunculated colon polyps, are often not amenable to conventional resection techniques. Aim of this study was to evaluate effectiveness and safety of endoscopic submucosal dissection (ESD) of HR-CANs. Methods In this real-world, multicenter, retrospective study, we included consecutive IBD patients referred to nine Tertiary Italian Endoscopy Centers (January 2014 - April 2023) to undergo an ESD or a hybrid-ESD (hESD), for HR-CANs. The primary outcome was rate of en bloc, R0 resection and adverse events (AEs). The secondary outcome was rate of local recurrence, metachronous lesions, and post-dissection surgery. Results 96 HR-CANs (89.6% non-polypoid, 79.2% left-side colon, 34.8 mm ± 16.2 mm, 15.6% invasive pit-pattern) in 91 patients with colonic IBD (58.2% male, 60.8 ± 12.2 years, 83.4% ulcerative colitis, disease duration of 183 ± 104 months, 14.3% endoscopic activity) were included. ESD and hESD were performed in 82.3% and 17.7% of cases. The final histopathological diagnoses were serrated sessile lesions in 14.6%, low-grade dysplasia in 32.3%, high-grade dysplasia in 38.5%, adenocarcinoma in 14.6%. Overall, en bloc and R0 resection were achieved in 95.9% and 85.4% of cases. AEs occurred in 12.5% of cases, all managed endoscopically and conservatively. After a mean follow-up of 23.4 months, local recurrence and metachronous lesions occurred each in 3.1% (n=3) of cases. Post-dissection surgery was required in 11.5% (n=11) of cases (7 for histopathology, 2 for recurrences, 2 for refractory IBD). At univariate analysis the left site was identified as a predictor of higher rate of en bloc resection (OR 0.07; 0.007-0.77; p=0.02), while the female sex as a predictor of lower rate of AEs (OR 0.17; 0.03-0.81; p=0.02). Further, the invasive pit pattern was associated with higher rate of post-dissection surgery (OR 6.25; 1.6-24.3; p=0.008). Conclusion Our findings showed that ESD of HR-CANs, when performed in Tertiary Endoscopy Centers, was effective and safe in patients with colonic IBD. However, further prospective studies including a long-term follow-up are still required to highlight the impact of ESD for IBD patients’ dysplasia-free survival.

COLD SNARE POLYPECTOMY: A SAFE PROCEDURE FOR REMOVING SMALL NON-PEDUNCULATED COLORECTAL LESIONS.

Polypectomy is an important treatment option for preventing colorectal cancer. Incomplete polyp resection (IPR) is re-cognized as a risk factor for interval cancer. The primary objective was to evaluate the complete polyp resection (CPR) rate for cold snare polypectomy (CSP) in small non-pedunculated polyps and, secondarily, specimen retrieval and complication rates. We prospectively evaluated 479 polyps <10 mm removed by CSP in 276 patients by an inexperienced endoscopist. A total of 476 polyps (99.4%) were resected en bloc. A negative margin (classified as CPR) was observed in 435 polyps (90.8%). An unclear or positive margin (classified as IPR) was observed in 43 cases (9.0%) and 1 case (0.2%), respectively, for an overall IPR rate of 9.2% (44/479). The IPR rate was 12.2% in the first half of cases and 5.9% in the second half (P=0.02). Dividing into tertiles, the IPR rate was 15.0% in the first tertile, 6.9% in the second tertile, and 5.7% in the third tertile (P=0.01). Dividing into quartiles, the IPR rate was 15.8% in the first quartile and 5.9% in the fourth quartile (P=0.03). The IPR rate was 6.3% for type 0-IIa lesions and 14.1% for type 0-Is lesions (P=0.01). For serrated and adenomatous lesions, the IPR rate was 9.2%. Specimen retrieval failed in 3.6% of cases. Immediate bleeding (>30 s) occurred in 1 case (0.2%), treated with argon plasma coagulation. No delayed bleeding or perforation occurred. CSP is a safe technique that provides good results for the resection of small non-pedunculated polyps, with a short learning curve.

A novel tool for case selection in endoscopic mucosal resection training.

As endoscopic mucosal resection (EMR) of large (≥ 20 mm) adenomatous nonpedunculated colonic polyps (LNPCPs) becomes widely practiced outside expert centers, appropriate training is necessary to avoid failed resection and inappropriate surgical referral. No EMR-specific tool guides case selection for endoscopists learning EMR. This study aimed to develop an EMR case selection score (EMR-CSS) to identify potentially challenging lesions for "EMR-naïve" endoscopists developing competency. Consecutive EMRs were recruited from a single center over 130 months. Lesion characteristics, intraprocedural data, and adverse events were recorded. Challenging lesions with intraprocedural bleeding (IPB), intraprocedural perforation (IPP), or unsuccessful resection were identified and predictive variables identified. Significant variables were used to form a numerical score and receiver operating characteristic curves were used to generate cutoff values. Of 1993 LNPCPs, 286 (14.4 %) were in challenging locations (anorectal junction, ileocecal valve, or appendiceal orifice), 368 (18.5 %) procedures were complicated by IPB and 77 (3.9 %) by IPP; 110 (5.5 %) procedures were unsuccessful. The composite end point of IPB, IPP, or unsuccessful EMR was present in 526 cases (26.4 %). Lesion size, challenging location, and sessile morphology were predictive of the composite outcome. A six-point score was generated with a cutoff value of 2 demonstrating 81 % sensitivity across the training and validation cohorts. The EMR-CSS is a novel case selection tool for conventional EMR training, which identifies a subset of adenomatous LNPCPs that can be successfully and safely attempted in early EMR training.

New Model to Predict Recurrence After Endoscopic Mucosal Resection of Non-pedunculated Colonic Polyps ≥ 20mm.

Polyp recurrence is common after endoscopic mucosal resection (EMR) of non-pedunculated colonic polyps ≥ 20mm. Two models haven been published for polyp recurrence prediction: Sydney EMR recurrence tool (SERT) and the size, morphology, colonic site, and access to target (SMSA) score. None of these models have been evaluated in a real-world United States (U.S.) cohort. We aimed to evaluate the external validity of these two models and develop a new model. Retrospective cohort study of patients with non-pedunculated polyps ≥ 20mm that underwent EMR between 1/1/2012 and 6/30/2020. Univariate and multivariate analysis were performed to identify predictors of polyp recurrence to build a new model. Receiver Operating Characteristic (ROC) curves for the new model, SERT and a modified version of SMSA were derived and compared. A total of 461 polyps from 461 unique patients were included for analysis. The average polyp size was 29.1 ± 12.4mm. Recurrence rate at first or second surveillance colonoscopy was 29.0% at a 15.6months median follow up (IQR 12.3-17.4). A model was created with 4 variables from index colonoscopy: size > 40mm, tubulovillous adenoma histology, right colon location and piecemeal resection. ROC curves showed that the Area Under the ROC (AUC) for the new model was 0.618, for SERT 0.538 and for mSMSA 0.550. SERT score and mSMSA have poor external validity to predict polyp recurrence after EMR of non-pedunculated polyps > 20mm. Our new model is simpler and performs better in this multiethnic, non-referral cohort from the U.S.

Endoscopic Mucosal Resection of Non-pedunculated Colorectal Polyps ≥20mm: Outcome in a Self-taught Skills Environment.

Endoscopic mucosal resection (EMR) of non-pedunculated colorectal polyps ≥20mm is technically demanding and should preferentially be performed by specialist endoscopists in referral centres. Little is known about the outcome in institutions establishing this competency. Here, we report the learning curve on 100 consecutive large non-pedunculated polyps resected by a single endoscopist with self-taught acquisition of skills. We analysed data on 100 non-supervised EMR procedures performed at our academic endoscopy centre (2016-2021), representing a single endoscopist's learning curve beginning with the first polyp ≥20 mm. The median polyp size was 30 mm (20-70mm), and 61% of all polyps were ≥30 mm. Predominant polyp morphology was 0-Is (34%) or 0-IIa (47%), and most polyps developed in the ascending colon (36%). In total, 20% of polyps showed high-grade intraepithelial neoplasia, and 8% included pT1 carcinoma. Adenoma recurrence rate after piecemeal resection was 21%. All but one recurrent adenoma were treated endoscopically. Deep mural injury, intra-procedural bleeding and post-procedural bleeding were detected and managed endoscopically in 3%, 21%, and 4% of procedures, respectively. Overall, surgery could be avoided in 91% of all and 98% of non- malignant polyps. Results for the first 50 polyps did not differ from results for the following polyps. Structured training is advisable to acquire advanced EMR skills. Our data show that autonomous acquisition of skills after finishing a training course represents an acceptable alternative with good results in the setting of an open error culture. Continuous review of outcome parameters and complication rate is mandatory during the learning process.

Incomplete resection rates of 4- to 20-mm non-pedunculated colorectal polyps when using wide-field cold snare resection with routine submucosal injection

Background and study aims Incomplete resection of 4- to 20-mm colorectal polyps occur frequently (> 10 %), putting patients at risk for post-colonoscopy colorectal cancer. We hypothesized that routine use of wide-field cold snare resection with submucosal injection (CSP-SI) might reduce incomplete resection rates (IRRs). Patients and methods Patients aged 45 to 80 years undergoing elective colonoscopies were enrolled in a prospective clinical study. All 4- to 20-mm non-pedunculated polyps were resected using CSP-SI. Post-polypectomy margin biopsies were obtained to determine IRRs through histopathology assessment. The primary outcome was IRR, defined as remnant polyp tissue found on margin biopsies. Secondary outcomes included technical success and complication rates. Results A total of 429 patients (median age 65 years, 47.1 % female, adenoma detection rate 40 %) with 204 non-pedunculated colorectal polyps 4 to 20 mm removed using CSP-SI were included in the final analysis. CSP-SI was technical successful in 97.5 % (199/204) of cases (5 conversion to hot snare polypectomy). IRR for CSP-SI was 3.8 % (7/183) (95 % confidence interval [CI] 2.7 %-5.5 %). IRR was 1.6 % (2/129), 16 % (4/25), and 3.4 % (1/29) for adenomas, serrated lesions, and hyperplastic polyps respectively. IRR was 2.3 % (2/87), 6.3 % (4/64), 4.0 % (6/151), and 3.1 % (1/32) for polyps 4 to 5 mm, 6 to 9 mm, < 10 mm, and 10 to 20 mm, respectively. There were no CSP-SI-related serious adverse events. Conclusions Use of CSP-SI results in lower IRRs compared to what has previously been reported in the literature for hot or cold snare polypectomy when not using wide-field cold snare resection with submucosal injection. CSP-SI showed an excellent safety and efficacy profile, however comparative studies to CSP without SI are required to confirm these results.

Endoscopic mucosal resection using cold snare versus hot snare in treatment for 10–19 mm non-pedunculated colorectal polyps: protocol of a non-inferiority randomised controlled study

IntroductionCold polypectomy has the advantages of simple operation, less time-consuming and fewer complications. Guidelines have recommended cold snare polypectomy (CSP) to resect small polyps sized ≤5 mm and sessile polyps...

Magnifying chromoendoscopy is a reliable method in the selection of rectal neoplasms for local excision.

Adequate staging of early rectal neoplasms is essential for organ-preserving treatments, but magnetic resonance imaging (MRI) frequently overestimates the stage of those lesions. We aimed to compare the ability of magnifying chromoendoscopy and MRI to select patients with early rectal neoplasms for local excision. This retrospective study in a tertiary Western cancer center included consecutive patients evaluated by magnifying chromoendoscopy and MRI who underwent en bloc resection of nonpedunculated sessile polyps larger than 20mm, laterally spreading tumors (LSTs) [Formula: see text] 20mm, or depressed-type lesions of any size (Paris 0-IIc). Sensitivity, specificity, accuracy, and positive and negative predictive values of magnifying chromoendoscopy and MRI to determine which lesions were amenable to local excision (i.e., [Formula: see text] T1sm1) were calculated. Specificity of magnifying chromoendoscopy was 97.3% (95% CI 92.2-99.4), and accuracy was 92.7% (95% CI 86.7-96.6) for predicting invasion deeper than T1sm1 (not amenable to local excision). MRI had lower specificity (60.5%, 95% CI 43.4-76.0) and lower accuracy (58.3%, 95% CI 43.2-72.4). Magnifying chromoendoscopy incorrectly predicted invasion depth in 10.7% of the cases in which the MRI was correct, while magnifying chromoendoscopy provided a correct diagnosis in 90% of the cases in which the MRI was incorrect (p = 0.001). Overstaging occurred in 33.3% of the cases in which magnifying chromoendoscopy was incorrect and 75% of the cases in which MRI was incorrect. Magnifying chromoendoscopy is reliable for predicting invasion depth in early rectal neoplasms and selecting patients for local excision.

A97 LARGE NON-PEDUNCULATED COLONIC POLYP (LNPCP) OUTCOMES REFERRED FOR ENDOSCOPIC RESECTION IN BRITISH COLUMBIA: A QUALITY ASSURANCE INITIATIVE

Abstract Background Endoscopic resection techniques have become the primary treatment strategy for the vast majority of large (≥ 20mm) non-pedunculated colonic polyps (LNPCPs). Despite this, surgery is still commonly performed with evidence suggesting an increasing trend over time. There is limited Canadian data confirming the effectiveness and safety of an endoscopic management strategy for LNPCPs. Purpose To investigate clinical outcomes of patients referred for endoscopic management of a LNPCP. Method Retrospective single-centre analysis of patients referred to a single endoscopist for the management of LNPCPs within a tertiary referral practice. LNPCPs were further subdivided into non-complicated (NC-LNPCP) or complicated (C-LNPCP) defined as those involving the ileocecal valve, appendiceal orifice, circumferential or previously attempted. Performance outcomes were evaluated by the frequencies of technical success (removal of all polypoid tissue during index procedure) and need for colorectal surgery. Safety was evaluated by the frequencies of clinically significant intraprocedural bleeding (CSIPB), clinically significant post-endoscopic resection bleeding (CSPEB), intra-procedural perforation and delayed perforation. Recurrence (either endoscopic or histologic) was evaluated at first surveillance colonoscopy (SC1). Continuous variables were summarized using median (IQR). Categorical variables were summarized as frequencies (%). To test for association between categorical variables, the Pearson χ2 or the Fisher exact test were used, where appropriate. For continuous variables, the Mann-Whitney U test was used. A probability (p) value of &amp;lt;0.05 was considered statistically significant. Result(s) Between January 2021 to March 2022, 263 LNPCP were referred for endoscopic resection and 41 LNPCP were excluded (23 pedunculated, 14 optical evaluation suggestive of deeply invasive cancer, 4 other). 222 LNPCP (188 NC-LNPCP, 34 C-LNPCP) underwent endoscopic resection. Median size was 25mm (IQR 20-30mm) with the majority undergoing cold snare resection (115, 51.8%). Polyposis (Adenomatous or serrated) was present in 23 (12.6%) cases respectively. Technical success was 97.3%. Cancer was present in 5 (2%). Clinically significant bleeding (CSPEB) occurred in 2.7%, DMI IV in 1.8% and there were no delayed perforations. Recurrence occurred in 4 (3.5%) at SC1 and 11 (5%) required surgery due to technical failure, submucosal invasion on pathology and clinically significant bleeding. Image Conclusion(s) Endoscopic resection as the primary treatment strategy for LNPCPs offers a safe and effective alternative to surgery in British Columbia. Please acknowledge all funding agencies by checking the applicable boxes below None Disclosure of Interest None Declared