Endoscopic Mucosal Resection Group Research Articles

Recurrence following successful eradication of neoplasia with endoscopic mucosal resection compared with endoscopic submucosal dissection in Barrett's esophagus: a retrospective comparison.

Endoscopic mucosal resection (EMR) and endoscopic submucosal dissection (ESD) are effective treatments for Barrett's neoplasia. However, little is known about recurrence rates following these techniques. We compared long-term neoplasia recurrence rates following EMR and ESD. This study included patients with Barrett's neoplasia (high grade dysplasia/adenocarcinoma) treated between July 2019 and December 2023 at a tertiary referral center in Canada. Outcomes were residual neoplasia at first follow-up, complete remission of neoplasia (CRN), and neoplasia recurrence following CRN. 157 patients were included (87 EMR, 70 ESD). Compared with EMR, the ESD group had larger lesions (median 2 vs. 3 cm, P<0.05), more adenocarcinoma (85.1% vs. 94.3%, P = 0.07), and deeper submucosal invasion (T1a: 71.6% vs. 75.8%; T1b-SM1: 25.7% vs. 6.1%; T1b≥SM2: 2.7% vs. 18.2%; P<0.05). Among 124 patients with follow-up (71 EMR, 53 ESD), 84.9% of ESD-treated patients had curative resections (i.e. R0 resection with low risk for lymph node metastasis), whereas 94.4% of EMR-treated patients had deep margin R0 resection of low risk lesions. At first follow-up, residual neoplasia (14.1% vs. 11.3%) and CRN (97.2% vs. 100%) were similar in the EMR and ESD groups, but neoplasia recurrence following CRN was significantly higher with EMR (13% vs. 1.9%, P<0.05), with cumulative probability of recurrence at 3 years of 18.3% vs. 4.2%, respectively. Neoplasia recurrence following CRN was significantly higher following EMR compared with ESD, suggesting that ESD may be superior to EMR in preventing neoplasia recurrence in Barrett's esophagus.

Treatment outcomes of endoscopic resection for nonampullary duodenal neuroendocrine tumors.

The incidence rate of duodenal neuroendocrine tumors has been increasing in recent years. Endoscopic resection [ER; endoscopic mucosal resection (EMR), endoscopic submucosal dissection (ESD)] is recommended for nonampullary duodenal neuroendocrine tumors (NAD-NETs) ≤10 mm in diameter that are confined to the submucosal layer and without lymph node or distant metastasis. However, the efficacy and safety of and indications for EMR/ESD remain unclear. Between November 2011 and April 2021, 12 NAD-NETs in 12 patients who underwent either EMR or ESD were analyzed retrospectively. The rates of en bloc resection, complete resection, pathologic complete resection, margin involvement, lymphovascular invasion, perineural invasion, complications and prognosis were determined during follow-up (median observation period 53.0 months). EMR was performed for two tumors, and ESD was performed for ten tumors. En bloc resection was performed for both tumors (100%) in the EMR group, and complete resection was achieved in one case (50%). Pathological complete resection was achieved in one case (50%), while in the ESD group, these three rates were 90% (9/10), 80% (8/10), and 80% (8/10), respectively. Intraoperative perforation occurred in one patient (10%) during ESD treatment, with no intraoperative or delayed bleeding in either group. Recurrence and distant metastasis were not observed during the mean follow-up period of 53.0 months (range, 18-131 months). For NAD-NETs that measure ≤10 mm in size, are confined to the submucosal layer and have neither suspicious lymph nodes nor distant metastasis, ER (EMR and ESD) may be a safe, effective, and feasible endoscopic technique for removing them.

Endoscopic Resections for Barrett's Neoplasia: A Long-Term, Single-Center Follow-Up Study.

Background and Objectives: Endoscopic mucosal resection (EMR) and endoscopic submucosal dissection (ESD) are both well-established and effective treatments for dysplasia and early cancer in Barrett's esophagus (BE). This study aims to compare the short- and long-term outcomes associated with these procedures in treating Barrett's neoplasia. Materials and Methods: This single-center retrospective cohort study included 95 patients, either EMR (n = 67) or ESD (n = 28), treated for Barrett's neoplasia at Sahlgrenska University Hospital between 2004 and 2019. The primary outcome was the complete (en-bloc) R0 resection rate. Secondary outcomes included the curative resection rate, additional endoscopic resections, adverse events, and overall survival. Results: The complete R0 resection rate was 62.5% for ESD compared to 16% for EMR (p < 0.001). The curative resection rate for ESD was 54% versus 16% for EMR (p < 0.001). During the follow-up, 22 out of 50 patients in the EMR group required additional endoscopic resections (AERs) compared to 3 out of 21 patients in the ESD group (p = 0.028). There were few adverse events associated with both EMR and ESD. In both the stratified Kaplan-Meier survival analysis (Log-rank test, Chi-square = 2.190, df = 1, p = 0.139) and the multivariate Cox proportional hazards model (hazard ratio of 0.988; 95% CI: 0.459 to 2.127; p = 0.975), the treatment group (EMR vs. ESD) did not significantly impact the survival outcomes. Conclusions: Both EMR and ESD are effective and safe treatments for BE neoplasia with few adverse events. ESD resulted in higher curative resection rates with fewer AERs, indicating its potential as a primary treatment modality. However, the survival analysis showed no difference between the methods, highlighting their comparable long-term outcomes.

Endoscopic submucosal dissection versus endoscopic mucosal resection for the treatment of rectal lesions involving the dentate line

BackgroundThe ideal treatment of epithelial neoplastic rectal lesions involving the dentate line is a controversial issue. Piecemeal endoscopic mucosal resection (EMR) is the most commonly used resection technique, but it is associated with high recurrence rates. Endoscopic submucosal dissection (ESD) has been shown to be safe and effective for the treatment of rectal lesions, but evidence is lacking concerning its application close to the dentate line. The aim of our study is to compare ESD and EMR for the treatment of epithelial rectal lesions involving the dentate line.MethodsWe identified all cases of endoscopic resections of rectal lesions involving the dentate line performed in two German high-volume centers between 2010 and 2022. Periinterventional and follow-up data were collected and retrospectively analyzed.ResultsWe identified 68 ESDs and 62 EMRs meeting our inclusion criteria. ESD showed a significant advantage in en bloc resection rates (89.7% vs. 9.7%; P = 0.001) and complete resection rates (72.1% vs. 9.7%; P = 0.001). The overall curative resection rate was similar between both groups (ESD: 92.6%, EMR: 83.9%; P = 0.324), whereas in the subgroup of low-risk adenocarcinomas ESD was curative in 100% of the cases vs. 14% in the EMR group (P = 0.002). There was one local recurrence after ESD (1,5%) vs. 16 (25.8%) after EMR (P < 0.0001), and the EMR patients required an average of three further interventions.ConclusionESD is superior to EMR for the treatment of epithelial rectal lesions involving the dentate line and should be considered the treatment of choice.

Low-power pure-cut hot snare polypectomy for colorectal polyps 10-14mm in size: a multicenter retrospective study.

Hot snare excision using electrocautery is widely used for large colorectal polyps (>10mm); however, adverse events occur due to deep thermal injury. Colorectal polyps measuring 10-14mm rarely include invasive cancer. Therefore, less invasive therapeutic options for this size category are demanding. We have developed hot snare polypectomy with low-power pure-cut current (LPPC HSP), which is expected to contribute to less deep thermal damage and lower risk of adverse events. This study aimed to evaluate the efficacy and safety of LPPC HSP for 10-14mm colorectal polyps, compared with conventional endoscopic mucosal resection (EMR). In this multicenter, retrospective, observational study, clinical outcomes of EMR and LPPC HSP for 10-14mm nonpedunculated colorectal polyps between January 2021 and March 2022 were compared using propensity score matching. We identified 203 EMR and 208 LPPC HSP cases. After propensity score matching, the baseline characteristics between the groups were comparable, with 120 pairs. The en bloc and R0 resection rates were not significantly different between EMR and LPPC HSP groups (95.8% vs 97.5%, P=0.72; 90.0% vs 91.7%, P=0.82). The rates of delayed bleeding and perforation did not differ between the groups. Compared with conventional EMR, LPPC HSP showed a similar resection ability without an increase in adverse events. These results suggest that LPPC HSP is a safe and effective treatment for 10-14mm nonpedunculated colorectal polyps.

Therapeutic efficacy analysis of endoscopic combined with serological diagnosis strategy and endoscopic in G1 and G2 gastric neuroendocrine neoplasms

Objective: To investigate the endoscopic combined serological diagnosis strategy for G1 and G2 gastric neuroendocrine neoplasms (G-NENs), and to evaluate the safety, short-term, and long-term efficacy of two endoscopic treatment procedures: endoscopic mucosal resection (EMR) and endoscopic submucosal dissection (ESD). Methods: This study retrospectively analyzed the clinical data of 100 consecutive patients with G-NENs who were hospitalized at the Cancer Hospital of the Chinese Academy of Medical Sciences from January 2011 to October 2023. These patients underwent endoscopic treatment, and propensity score matching (PSM) was used to compare clinicopathological characteristics, as well as short-term and long-term efficacy of lesions in the EMR group and ESD group before and after treatment. Results: Among the 100 patients with G-NENs, the median age was 54 years old. Before surgery, 29 cases underwent endoscopic combined serological examination, and 24 of them (82.2%) had abnormally elevated plasma chromogranin A. The combined diagnostic strategy for autoimmune atrophic gastritis (AIG) achieved a diagnostic accuracy of 100%(22/22). A total of 235 G-NEN lesions were included, with 84 in the ESD group and 151 in the EMR group. The median size of the lesions in the ESD group (5.0 mm) was significantly larger than that in the EMR group (2.0 mm, P＜0.001). Additionally, the ESD group had significantly more lesions with pathological grade G2[23.8%(20/84) vs. 1.3%(2/151), P＜0.001], infiltration depth reaching the submucosal layer [78.6%(66/84) vs. 51.0%(77/151), P＜0.001], and more T2 stage compared to the EMR group[15.5%(13/84) vs. 0.7%(1/151), P＜0.001]. After PSM, 49 pairs of lesions were successfully matched between the two groups. Following PSM, there were no significant differences in the en bloc resection rate [100.0%(49/49) vs. 100.0%(49/49)], complete resection rate [93.9%(46/49) vs. 100.0%(49/49)], and complication rate [0(0/49) vs. 4.1%(2/49)] between the two groups. During the follow-up period, no recurrence or distant metastasis was observed in any of the lesions in both groups. Conclusions: The combination of endoscopy and serology diagnostic strategy has the potential to enhance the accuracy of diagnosing G1 and G2 stage G-NENs and their background mucosa. Endoscopic resection surgery (EMR, ESD) is a proven and safe treatment approach for G1 and G2 stage G-NENs.

Rates of Recurrent Intestinal Metaplasia and Dysplasia After Successful Endoscopic Therapy of Barrett's Neoplasia by Endoscopic Mucosal Resection vs Endoscopic Submucosal Dissection and Ablation: A Large North American Multicenter Cohort.

Endoscopic eradication therapy (EET) combining endoscopic resection (ER) with endoscopic mucosal resection (EMR) or endoscopic submucosal dissection (ESD) followed by ablation is the standard of care for the treatment of dysplastic Barrett's esophagus (BE). We have previously shown comparable rates of complete remission of intestinal metaplasia (CRIM) with both approaches. However, data comparing recurrence after CRIM are lacking. We compared rates of recurrence after CRIM with both techniques in a multicenter cohort. Patients undergoing EET achieving CRIM at 3 academic institutions were included. Demographic and clinical data were abstracted. Outcomes included rates and predictors of any BE and dysplastic BE recurrence in the 2 groups. Cox-proportional hazards models and inverse probability treatment weighting (IPTW) analysis were used for analysis. A total of 621 patients (514 EMR and 107 ESD) achieving CRIM were included in the recurrence analysis. The incidence of any BE (15.7, 5.7 per 100 patient-years) and dysplastic BE recurrence (7.3, 5.3 per 100 patient-years) were comparable in the EMR and ESD groups, respectively. On multivariable analyses, the chances of BE recurrence were not influenced by ER technique (hazard ratio 0.87; 95% confidence interval 0.51-1.49; P = 0.62), which was also confirmed by IPTW analysis (ESD vs EMR: hazard ratio 0.98; 95% confidence interval 0.56-1.73; P = 0.94). BE length, lesion size, and history of cigarette smoking were independent predictors of BE recurrence. Patients with BE dysplasia/neoplasia achieving CRIM, initially treated with EMR/ablation, had comparable recurrence rates to ESD/ablation. Randomized trials are needed to confirm these outcomes between the 2 ER techniques.

Efficacy and safety of precutting endoscopic mucosal resection versus endoscopic submucosal dissection for non-ampullary superficial duodenal lesions

BackgroundEndoscopic treatments for non-ampullary superficial duodenal lesions (NASDLs) are yet to be standardized. Endoscopic submucosal dissection (ESD) for NASDLs demands advanced techniques and a long procedure time to prevent perforation and bleeding. Precutting endoscopic mucosal resection (EMR) is a technical modification of ESD that overcomes the limitations of ESD. This study aimed to compare the efficacy and safety of precutting EMR versus ESD for NASDLs. MethodsWe conducted a retrospective analysis of patients with NASDLs treated with either precutting EMR or ESD from January 2015 to March 2023. ResultsA total of 90 patients with NASDLs were analyzed, with 44 patients in the precutting EMR group and 46 patients in the ESD group. The endoscopic procedure achieved satisfactory outcomes in both groups, with en block resection rate of 100.0 %. The R0 resection rates in the precutting EMR and ESD groups were 95.5 % and 93.5 %, respectively. No delayed perforation occurred postoperatively in either group. There were no significant differences between the two groups in age, gender, lesion location, layer of lesion origin, macroscopic type, and lesion size. The procedure time was significantly shorter in the precutting EMR group than in the ESD group (22.9 ± 7.1 min vs 36.0 ± 10.6 min, p<0.001). The intraoperative perforation rate was significantly lower in the precutting EMR group compared to ESD group (4.5% vs 19.6 %, p = 0.030). ConclusionsPrecutting EMR is comparable to ESD for NASDLs, demonstrating a lower intraoperative perforation rate and shorter procedure time compared to ESD.

Histopathologic vertical margin positivity in cold snare polypectomy and mucosal resection for sessile serrated lesions

Background and AimsEvidence regarding the status of the vertical margin of sessile serrated lesions (SSLs) resected using cold snare polypectomy (CSP) is lacking, and whether a histopathologically positive vertical margin is related to recurrence remains unclear. Therefore, this preliminary study aimed to clarify the rates of positive or unevaluable vertical and horizontal margins and the rate of muscularis mucosae resection in SSLs treated using CSP compared with those treated with endoscopic mucosal resection (EMR). MethodsHistological outcomes of patients treated with CSP or EMR for SSL were evaluated in this single-center observational study. The primary outcome was the incidence of histopathologically positive vertical margins in CSP and EMR. Furthermore, the comparisons were adjusted for confounding factors using propensity score matching. ResultsOverall, 82 patients with SSLs were included in the CSP and EMR groups after matching. The incidence of positive histological vertical margins in the CSP and EMR groups were 67.1% and 2.4%, respectively (p<0.001). Regarding the evaluation of the presence of muscularis mucosae, 29.3% and 98.8% of the patients in the CSP and EMR groups, respectively, had a complete muscularis mucosae resection (p<0.001). ConclusionsA rigorous histopathologic evaluation revealed that for SSLs, CSP more frequently leads to positive vertical margins than EMR.

Tip-in Versus Conventional Endoscopic Mucosal Resection for Colorectal Neoplasia: A Systematic Review and Meta-analysis.

Early-stage gastrointestinal neoplasms are frequently treated with conventional endoscopic mucosal resection (C-EMR). However, C-EMR frequently leads to incomplete resection of large colorectal lesions. Tip-in endoscopic mucosal resection (EMR), which was recently introduced for en bloc resection of colorectal neoplasms, minimizes slippage during the procedure. We conducted a systematic review and meta-analysis of published studies that compared Tip-in EMR with conventional EMR. We searched several electronic databases and included studies that reported on the primary outcomes of en bloc resection rate and complete resection rate, as well as secondary outcomes such as procedure time and procedure-related complications (including perforation and delayed bleeding rate). We used a random effects model to calculate odds ratios (ORs) with 95% CIs for dichotomous data and weighted mean differences with 95% CIs for continuous data. We also conducted several sensitivity analyses to assess the robustness of our findings. A total of 11 studies involving 1244 lesions (684 in the Tip-in EMR group and 560 in C-EMR group) were included in the meta-analysis. Our meta-analysis showed that compared with conventional EMR, Tip-in EMR significantly increased the en bloc resection rate in patients with colorectal neoplasia (OR=3.61; 95% CI, 2.09-6.23; P <0.00001; I2 =0%) and had a higher complete resection rate (OR=2.49; 95% CI, 1.65-3.76; P <0.0001; I2 =0%). However, the procedure time and rates of procedure-related complications did not differ significantly between the 2 groups. Tip-in EMR outperformed C-EMR for both the en bloc and complete resection of colorectal lesions with similar rates of procedural complications.

Immediate Results of Colonic Flat Epithelial Neoplasms Removal Using Diathermic Snare Endoscopic Mucosal Resection and Mucosectomy Combined with Dissection in the Submucosal Layer: Comparative Assessment

Aim: to compare the immediate outcomes of removing colonic flat epithelial neoplasms by using diathermic snare endoscopic mucosal resection (EMR) and mucosectomy with endoscopic submucosal dissection (ESD).Materials and methods. Ninety-six endoscopic procedures were conducted on the colon of 93 patients with flat epithelial neoplasms. The mean age of patients was 64.9 ± 10.7 years, with an age range of 39 to 88 years. The size range of epithelial neoplasms was 20 to 70 mm, with a median of 37.4 ± 14.8 mm. Only patients with benign epithelial neoplasms were included in the study since patients with suspected malignancy in laterally spreading tumors are indicated for ESD intervention to avoid fragmentary excision and risk of colorectal cancer progression due to possible positive resection margins. The patients were separated into two equally sized groups and treated with EMR and ESD methods.Results. Epithelial neoplasms in the ESD group had an average size of 41.6 ± 15 mm while those in the EMR group had an average size of 33.1 ± 13.5 mm. The ESD group had an average intervention time of 143.6 ± 102.9 min, whereas the EMR group had an average intervention time of 52.6 ± 34.4 min. Both groups (96 adenomas) had a total of 10 (10.4 %) patients who experienced colonic perforations during the intervention, with 4 (4.1 %) cases observed in the EMR group and 6 (6.2 %) in the ESD group. No statistically significant differences were identified in the occurrence of perforations during the operation (p = 0.7401). ESD resulted in an en bloc removal rate of 44/48 (91.6 %), whereas EMR only achieved a rate of 14/48 (29.1 %).Conclusion. Endoscopic mucosectomy with submucosal dissection (ESD), in contrast to endoscopic mucosal resection (EMR) with diathermic snare, provides a higher frequency of tumor removal en bloc, regardless of tumor size, but is characterized by a longer duration of intervention (p &lt; 0.0001). In the ESD group, there were twice as many intraoperative bleedings (p = 0.0061) due to the longer duration and technical complexity of the procedure. There were no statistically significant differences in the incidence of late complications between the groups (p = 0.9999). Local recurrence of adenoma developed in two patients (4.1 %) after pEMR, statistically significant differences were noted (p &lt; 0.0006).

Comparing efficacy and factors of postoperative bleeding in endoscopic mucosal resection vs coagulation for intestinal polyps.

This study aimed to assess the effectiveness of Endoscopic Mucosal Resection (EMR) and Argon Plasma Coagulation (APC) as therapeutic approaches for intestinal polyps in patients, and to examine the factors associated with postoperative bleeding. This study included 132 patients diagnosed with colorectal polyps (188 polyps) who underwent endoscopic surgery at our hospital between January 2022 and December 2022. Based on the surgical method employed, the patients were divided into 2 groups: EMR (68 cases, 97 polyps) and APC (64 cases, 91 polyps). Comparative analyses were conducted to assess the clinical efficacy, surgery-related indicators, and quality of life the 2 groups. Furthermore, an investigation was carried out to identify the factors associated with postoperative bleeding. The analysis revealed no statistically significant difference in the cure rate of flat and superficial raised polyps between the EMR group and the APC (P > .05). However, it was found that the EMR group exhibited a significantly higher cure rate for subpedunculated and raised-pedunculated polyps compared to the APC group (P < .05). The results of logistics analysis showed that patients with hypertension (OR = 2.876, 95% CI: 1.119-7.393), patients with diabetes (OR = 5.278, 95% CI: 1.388-20.064), patients with hyperlipidemia (OR = 2.594, 95% CI: 1.054-6.380), the polyps of right hemicolon (OR = 2.743, 95% CI: 1.003-7.504), rectal polyps (OR = 5.143, 95% CI: 1.728-7.504), pedunculated polyps (OR = 4.758, 95% CI: 1.322-17.129), adenomatous polyps (OR = 3.152, 95% CI: 1.018-9.757) were independent risk factors for postoperative bleeding in patients with colorectal polyps (P < .05). The findings suggest that for subpedunculated and pedunculated-raised polyps, EMR can be a suitable treatment approach. On the other hand, flat and superficial-raised polyps can be effectively managed with either EMR or APC. The presence of hypertension, diabetes, hyperlipidemia, polyps of the right hemicolon, rectal polyps, pedunculated polyps, and adenomatous polyps has been established as independent risk factors for postoperative bleeding in patients with colorectal polyps.

Hot snare polypectomy vs endoscopic mucosal resection using bipolar snare for intermediate size colorectal lesions: Propensity score matching.

Endoscopic resection (ER) with bipolar snare, in which the electric current only passes through the tissue between the device's two electrodes, is a prominent method used to prevent perforation due to electricity potentially. ER using bipolar snare with or without submucosal injection enabled safe resection of colorectal lesions measuring 10-15 mm in an ex vivo porcine model. ER with bipolar snare is expected to have good treatment outcomes in 10-15 mm colorectal lesions, with high safety even without submucosal injection. However, no clinical reports have compared treatment outcomes with and without submucosal injection. To compare the treatment outcomes of bipolar polypectomy with hot snare polypectomy (HSP) to those with endoscopic mucosal resection (EMR). In this single-centre retrospective study, we enrolled 10-15 mm nonpedunculated colorectal lesions (565 Lesions in 463 patients) diagnosed as type 2A based on the Japan Narrow-band Imaging Expert Team classification, resected by either HSP or EMR between January 2018 and June 2021 at the National Cancer Center Hospital East. Lesions were divided into HSP and EMR groups, and propensity score matching was performed. In the matched cohort, en bloc and R0 resection rates and adverse events were compared between the two groups. Of the 565 lesions in 463 patients, 117 lesions each in the HSP and EMR groups were selected after propensity score matching. In the original cohort, there was a significant difference in antithrombotic drug use (P < 0.05), lesion size (P < 0.01), location (P < 0.01), and macroscopic type (P < 0.05) between the HSP and EMR groups. In the matched cohort, the en bloc resection rates were comparable between both groups [93.2% (109/117) vs 92.3% (108/117), P = 0.81], and there was no significant difference in the R0 resection rate [77.8% (91/117) vs 80.3% (94/117), P = 0.64]. The incidence of delayed bleeding was similar in both groups [1.7% (2/117)]. Perforation occurred in the EMR group [0.9% (1/117)] but not in the HSP group. Using bipolar snare, ER of nonpedunculated 10-15 mm colorectal lesions may be performed safely and effectively, even without submucosal injection.

Conventional endoscopic mucosal resection versus modified endoscopic mucosal resection for duodenal neuroendocrine tumor.

As the incidence of duodenal neuroendocrine tumors (DNET) is steadily increasing, the role of endoscopic treatment for appropriate lesions is becoming more significant. We aimed to compare the outcomes according to lesion size and endoscopic mucosal resection (EMR) techniques for DNET treatment. Patients who underwent endoscopic treatment for DNET between June 2000 and December 2019 were included. The clinicopathologic features and treatment outcomes were investigated by reviewing medical records. Overall, 104 cases underwent endoscopic resection for nonampullary DNET, including conventional EMR (n = 57), cap-assisted EMR (EMR-C, n = 19), and precut EMR (EMR-P, n = 28). The en bloc resection rates (100% vs. 94.7% vs. 96.4%) and histologic complete resection rates (45.6% vs. 52.6% vs. 57.1%) were not significantly different between the EMR, EMR-C, and EMR-P groups. The histologic complete resection rates were significantly higher in lesions < 10mm than in lesions ≥ 10mm (69.8% vs. 38.9%, P = 0.013). In lesions < 10mm, perforation occurred more frequently in the modified EMR group than in the conventional EMR group (13.2% vs. 0.0%, P = 0.007). During the median follow-up period of 88.0months, the recurrence-free survival (92.2% vs. 94.4% vs. 92.1%) and overall survival (98.0% vs. 88.1% vs. 100.0%) rates did not show significant differences between the EMR, EMR-C, and EMR-P groups. Conventional EMR and modified EMR are feasible and effective for the treatment of nonampullary DNET sized < 10mm and limited to mucosal and submucosal layer. Additionally, endoscopists should be aware of the high risk of perforation in modified EMR.

354. THE PARADIGM OF INACCURACIES IN STAGING EARLY OESOPHAGEAL ADENOCARCINOMA

Abstract The clinical value of multiple staging investigations for high-grade dysplasia (HGD) or early adenocarcinoma of the oesophagus (EOC) is unclear. A single centre prospective cohort of patients treated for EOC between 2000 and 2019 was analysed. This coincided with a transition period from oesophagectomy to endoscopic mucosal resection (EMR) as the treatment of choice for early cancers. All patients were staged with computed tomography (CT), endoscopic ultrasound (EUS), and 2-deoxy-2-[18F]fluoro-d-glucose (FDG) positron emission tomography (PET)-CT. The aim of this study was to assess the accuracy of these investigations and impact on clinical management. 297 patients with HGD or EOC were included (EMRn = 184; oesophagectomy n = 113 [preceded by EMRn = 23]). Staging patterns for both groups were similar throughout staging modalities (CT, EUS, PET-CT), showing low overall accuracy. In the EMR group, over-staging that might have changed management occurred in 10 patients (3.6%)for T-staging (T2) and 14 patients (5.0%)for positive lymph node-staging (LNM). In the oesophagectomy alone group LNM identified following surgery was rare (8.9%) and staging sensitivity for these surgically treated patients was low (CT 12.5%, EUS 12.5%, PET-CT 0.0%). Overall, PET-CT and EUS changed decision-making in less than 1%of patients with a clear CT and low risk histology criteria on EMR specimen. Staging accuracy is low in EOC and the addition of EUS and PET-CT does not change patient decision making significantly. Histology obtained from EMR specimens contain important predicting factors that do change patient management, proving to be an excellent staging tool rather than imaging techniques, hence, EUS and PET-CT should only be used selectively in patients being assessed for EOC.

A127 ENDOSCOPIC MUCOSAL RESECTION FOR DYSPLASTIC AND NEOPLASTIC BARRETT’S ESOPHAGUS: FINDINGS FROM A FOREGUT NEOPLASIA MULTIDISCIPLINARY DATABASE

Abstract Background Previously, Barrett’s esophagus with high grade dysplasia (HGD) or neoplasia was treated with esophagectomy, which is associated with a high postoperative morbidity and mortality rate. Recent guidelines support the use of endoscopic mucosal resection (EMR) for T1a esophageal adenocarcinoma (EAC) and potentially T1b EAC; however, data on long term outcomes of endoscopic treatment is lacking. We created a combined prospective and retrospective multidisciplinary database to monitor outcomes of patients with Barrett’s esophagus undergoing endoscopic treatment. Aims Our primary aim was to compare outcomes of EMR and esophagectomy in patients presenting with BE and HGD, and/or early EAC. Methods A collaboration of gastroenterologists, general surgeons and thoracic surgeons from the University of Alberta, Edmonton, Alberta, provided input on the development of the database. All patients referred to the Northern Alberta Endoscopic Ablation Program from 2009–2021 who received at least one endoscopic treatment were included. A sub-analysis of all patients with pathologic confirmation of HGD, and/or early EAC was conducted to compare outcomes of EMR and esophagectomy. Results A total of 212 patients have been entered into the database. The most common findings were HGD, low grade dysplasia (LGD), and adenocarcinoma, respectively. All patients (n=48) who had at least LGD reached complete eradication of dysplasia (CE-D) and 95.8% reached complete eradication of intestinal metaplasia (CE-IM). Of those patients that reached CE-D, 8.3% developed recurrence of dysplasia (n=4). In the sub-analysis, 74 patients (76.3%) received endoscopic therapy while 23 patients (23.7%) received endoscopic therapy then ultimately an esophagectomy. There were significantly more T1b lesions in the esophagectomy group compared to the EMR group ( p&amp;lt;0.0001). Of all the patients in the EMR group, only 5.4% (n=4) had treatment related complications. Of patients receiving an esophagectomy, 60.9% (n=14) experienced treatment related complications. The mean length of stay for patients in the EMR group was 1.03 +/- 0.2 days, compared to 16.5 +/- 11.8 days for esophagectomy ( p&amp;lt;0.0001). Conclusions EMR provides definitive and durable treatment for BE lesions classified as T1b or less severe, with fewer complications and a shorter length of hospital stay than esophagectomy. Funding Agencies Alberta Innovates Health Solutions

Prognosis of rectal neuroendocrine tumors after endoscopic resection: a single-center retrospective study.

The efficacy of endoscopic resection in patients with rectal neuroendocrine tumors (NETs) which are less than 20 mm in diameter remains unclear. This study aimed to investigate the efficacy and outcomes of different types of endoscopic resection in patients with NETs. We performed a retrospective analysis and follow-up on 98 patients who underwent endoscopic resection for rectal NETs between August 2010 and October 2019 at Guangdong Provincial People's Hospital, China. The lesions were preoperatively classified according to their endoscopic morphology and measured by endoscopic ultrasound. Patients were divided into modified endoscopic mucosal resection (EMR) and endoscopic submucosal dissection (ESD) groups depending on the endoscopic treatment they received. The en bloc resection rate, histopathological complete resection rate, and the complication rate of the 2 groups were evaluated after the operation. The risk factors for incomplete resection were also analyzed. The average diameter of the 98 NETs was 6.29±2.90 mm (range, 2-15 mm). The en bloc resection rate of the modified EMR and ESD treatment groups was 97.2% (35/36) and 100% (62/62), respectively. The histopathological complete resection rate was 86.1% (31/36) and 87.1% (54/62), respectively. No tumor recurrence or tumor-related death occurred. There were no statistically significant differences in the rate of histopathological complete resection, perforation, or delayed hemorrhage between the 2 groups (P>0.05). Multivariate analysis demonstrated that the depth of tumor invasion (P=0.007) and tumor diameter (P<0.001) were independent risk factors for histopathological complete resection. Modified EMR and ESD are safe and effective endoscopic approaches for the resection of rectal NETs ≤15 mm in diameter. Endoscopic resection requires a comprehensive preoperative evaluation of risk factors including the depth of tumor invasion and tumor diameter.

Prospective evaluation of the effectiveness of colonoscopic polyp resection

Background: Colon cancer incidence is on the rise and despite having undergone a colonoscopy to screen and remove all visible polyps as a preventive measure, nearly 1 in 110 patients will develop colon cancer within 3 years. The three main possible explanations for this are missing polyps, incompletely removed polyps, or rapidly growing tumors. Objective: To determine the proportion of colonic polyps ≤ 3 cm in size that show evidence of residual polyp tissue following colonoscopy and polypectomy. Methods: Patients who presented for colonoscopy at a community center were invited to participate in this study. Those who had confirmed adenoma were invited to repeat the procedure in 2 to 6 months with biopsies at the resection site to check for the presence of residual polyp tissue. Exclusion criteria included the absence of adenoma in the resected lesion, contraindication to polypectomy or follow-up colonoscopy, refusal to participate in follow-up examination, and other conditions increasing colon cancer risk. If polyps between 5 mm and 30 mm were found, the endoscopist resected them using the hot snare polypectomy technique or endoscopic mucosal resection (EMR). Results: Ninety-one patients completed the study protocol, with 105 lesions being studied. The second procedure was performed between 2 and 24 months. All analyzed lesions were adenoma, and three of them were associated with intramucosal adenocarcinoma. Others included 60 tubular lesions, 37 tubulovillous lesions, and 5 serrated lesions. Thirty-two lesions were flat and were removed by EMR; polypectomy was performed for 73 lesions. There was no residual tissue in the polypectomy group. The EMR group presented three cases of incomplete resection without adenocarcinomas. Conclusion: Our study showed that flat lesions might be an important cause of incomplete resection. In addition, we documented the complete resection of pedunculated lesions in all studied patients. This study provides more evidence to validate the empirical perception in the medical field that assumes the complete resection of pedunculated polyps. Therefore, we suggest that patients who undergo snare removal of pedunculated polyps should follow the regular protocol for colon cancer screening, with colonoscopy every 5 to 10 years. Meanwhile, the surveillance scheme should be reviewed for patients who undergo removal of flat lesions smaller than 30 mm.

Comparison of cold snare polypectomy and endoscopic mucosal resection for 3-10-mm colorectal polyps in end-stage renal disease patients.

Background:Patients with end-stage renal disease (ESRD) have a higher incidence of clinically relevant complications, such as bleeding and perforation after polyp resection, compared to patients without underlying diseases. Cold snare polypectomy (CSP) is increasingly used for the removal of small polyps and diminutive polyps due to its shorter procedure time and low risk of bleeding and perforation. However, there have been few studies on the effectiveness and safety of CSP in patients with ESRD. The aim of this study was to compare the efficacy and safety of CSP and endoscopic mucosal resection (EMR) in ESRD patients.Methods:This study was a retrospective study. We performed propensity score-matched analysis in patients with ESRD who underwent endoscopic resection for 3–10-mm-sized colorectal polyps at Seoul St. Mary's Hospital, from January 2014 to December 2019.Results:After 1:1 ratio matching, 406 polyps were included: 203 polyps were resected with CSP and 203 polyps with EMR. There was no difference between the CSP group and EMR group in incomplete resection rate (4.43% vs. 1.97%, P = 0.16). There were no differences between the CSP and EMR group for immediate bleeding (5.42% vs. 7.88%, P = 0.32) and delayed bleeding (0% vs. 0.49%, P = 1.00). No perforation occurred in either group.Conclusions:There were no differences between the CSP and EMR group in terms of efficacy and safety. CSP can be one of the standard methods for the removal of 3–10-mm-sized colorectal polyps in patients with ESRD.

Anchoring the snare tip is a feasible endoscopic mucosal resection method for small rectal neuroendocrine tumors

Small rectal neuroendocrine tumors (NETs) can be treated using cap-assisted endoscopic mucosal resection (EMR-C), which requires additional effort to apply a dedicated cap and snare. We aimed to evaluate the feasibility of a simpler modified endoscopic mucosal resection (EMR) technique, so-called anchored snare-tip EMR (ASEMR), for the treatment of small rectal NETs, comparing it with EMR-C. We retrospectively evaluated 45 ASEMR and 41 EMR-C procedures attempted on small suspected or established rectal NETs between July 2015 and May 2020. The mean (SD) lesion size was 5.4 (2.2) mm and 5.2 (1.7) mm in the ASEMR and EMR-C groups, respectively (p = 0.558). The en bloc resection rates of suspected or established rectal NETs were 95.6% (43/45) and 100%, respectively (p = 0.271). The rates of histologic complete resection of rectal NETs were 94.1% (32/34) and 88.2% (30/34), respectively (p = 0.673). The mean procedure time was significantly shorter in the ASEMR group than in the EMR-C group (3.12 [1.97] vs. 4.13 [1.59] min, p = 0.024). Delayed bleeding occurred in 6.7% (3/45) and 2.4% (1/41) of patients, respectively (p = 0.618). In conclusion, ASEMR was less time-consuming than EMR-C, and showed similar efficacy and safety profiles. ASEMR is a feasible treatment option for small rectal NETs.