Conventional Endoscopic Mucosal Resection Research Articles

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.

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.

Present situation of minimally invasive surgical treatment for early gastric cancer.

Minimally invasive surgery is a kind of surgical operation, which is performed by using professional surgical instruments and equipment to inactivate, resect, repair or reconstruct the pathological changes, deformities and wounds in human body through micro-trauma or micro-approach, in order to achieve the goal of treatment, its surgical effect is equivalent to the traditional open surgery, while avoiding the morbidity of conventional surgical wounds. In addition, it also has the advantages of less trauma, less blood loss during operation, less psychological burden and quick recovery on patients, and these minimally invasive techniques provide unique value for the examination and treatment of gastric cancer patients. Surgical minimally invasive surgical techniques have developed rapidly and offer numerous options for the treatment of early gastric cancer (EGC): endoscopic mucosal resection (EMR), underwater EMR (UEMR), endoscopic submucosal dissection (ESD), endoscopic full-thickness resection (EFTR), endoscopic submucosal excavation (ESE), submucosal tunnel endoscopic resection), laparoscopic and endoscopic cooperative surgery (LECS); Among them, EMR, EFTR and LECS technologies have a wide range of applications and different modifications have been derived from their respective surgical operations, such as band-assisted EMR (BA-EMR), conventional EMR (CEMR), over-the-scope clip-assisted EFTR, no-touch EFTR, the inverted LECS, closed LECS, and so on. These new and improved minimally invasive surgeries are more precise, specific and effective in treating different types of EGC.

Underwater versus conventional endoscopic mucosal resection for ≥10 mm sessile or flat colorectal polyps: A systematic review and meta-analysis.

Underwater endoscopic mucosal resection (UEMR) has been an emerging substitute for conventional EMR (CEMR). This systematic review and meta-analysis aimed at comparing the efficiency and safety of the two techniques for removing ≥10 mm sessile or flat colorectal polyps. PubMed, Cochrane Library and Embase databases were searched up to February 2023 to identify eligible studies that compared the outcomes of UEMR and CEMR. This meta-analysis was conducted on the en bloc resection rate, R0 resection rate, complete resection rate, procedure time, adverse events rate and recurrence rate. Nine studies involving 1,727 colorectal polyps were included: 881 were removed by UEMR, and 846 were removed by CEMR. UEMR was associated with a significant increase in en bloc resection rate [Odds ratio(OR) 1.69, 95% confidence interval(CI) 1.36-2.10, p<0.00001, I2 = 33%], R0 resection rate(OR 1.52, 95%CI 1.14-2.03, p = 0.004, I2 = 31%) and complete resection rate(OR 1.67, 95%CI 1.06-2.62, p = 0.03, I2 = 0%) as well as a significant reduction in procedure time(MD ‒4.27, 95%CI ‒7.41 to ‒1.13, p = 0.008, I2 = 90%) and recurrence rate(OR 0.52, 95%CI 0.33-0.83, p = 0.006, I2 = 6%). Both techniques were comparable in adverse events rate. UEMR can be a safe and efficient substitute for CEMR in removing ≥10 mm sessile or flat colorectal polyps. More studies verifying the advantages of UEMR over CEMR are needed to promote its application.

Outcomes of cold snare EMR of nonampullary duodenal adenomas ≥1 cm: a multicenter study

Endoscopic mucosal resection (EMR) with use of electrocautery (conventional EMR) has historically been used to remove large duodenal adenomas; however, use of electrocautery can predispose to adverse events including delayed bleeding and perforation. Cold snare EMR (cs-EMR) has been shown to be safe and effective for removal of colon polyps, but data regarding its use in the duodenum are limited. The aim of this study was to evaluate the efficacy and safety of cs-EMR for nonampullary duodenal adenomas≥1 cm. This was a multicenter retrospective study of patients with nonampullary duodenal adenomas≥1 cm who underwent cs-EMR from October 2014 to May 2023. Patients who received any form of thermal therapy were excluded. Primary outcomes were technical success and rate of recurrent adenoma. Secondary outcomes were adverse events and predictors of recurrence. A total of 125 patients underwent resection of 127 nonampullary duodenal adenomas with cs-EMR. Follow-up data were available in 89 cases (70.1%). The recurrent adenoma rate was 31.5% (n= 28). Adverse events occurred in 3.9% (n= 5), with 4 cases of immediate bleeding (3.1%) and 1 case of delayed bleeding (.8%). There were no cases of perforation. The presence of high-grade dysplasia was found to be an independent predictor of recurrence (odds ratio, 10.9 [95% confidence interval, 1.1-102.1]; P= .036). This retrospective multicenter study demonstrates that cs-EMR for nonampullary duodenal adenomas is safe and technically feasible with an acceptable recurrence rate. Future prospective studies are needed to directly compare outcomes of cs-EMR with conventional and underwater EMR.

Can underwater endoscopic mucosal resection be an alternative to conventional endoscopic mucosal resection for superficial non-ampullary duodenal epithelial tumors?

Underwater endoscopic mucosal resection (UEMR) is a simpler procedure for superficial non-ampullary duodenal epithelial tumors (SNADET) than conventional endoscopic mucosal resection (cEMR). This study aimed to evaluate whether cEMR can be substituted by UEMR for SNADET in terms of effectiveness, safety, and learning curve. A total of 157 consecutive patients with 203 SNADETs ≤20mm in diameter, including 107 lesions resected by cEMR and 96 lesions resected by UEMR, between January 2019 and May 2023, were retrospectively recruited. The treatment outcomes were compared between the cEMR and UEMR groups. The risk factors for incomplete resection by UEMR were analyzed using univariate and multivariate analyses. Lesions in the UEMR group were divided chronologically into five periods; thereafter, the en bloc resection rate and procedure time were compared. No significant differences existed between the cEMR and UEMR groups in the mean procedure time (3.9min vs. 3.6min, p=0.1380) or en bloc resection rate (91% vs. 94%, p=0.4138). No perforation was observed in either group. Tumor size was an independent risk factor for incomplete resection using UEMR (p<0.01). The history of biopsy was not associated with incomplete resection using UEMR. The en bloc resection rate of UEMR was 100% (20/20) in the first period and ranged from 90% to 100% over all periods. UEMR is safe and effective for SNADET ≤20mm, regardless of a history of biopsy, and is easy to learn. Thus, UEMR can serve as an alternative to cEMR.

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.

Conventional versus underwater endoscopic resection for superficial non-ampullary duodenal epithelial tumours.

Several endoscopic resection methods have been developed as less invasive treatments for superficial non-ampullary duodenal epithelial tumours. This study aimed to compare outcomes of conventional endoscopic mucosal resection and underwater endoscopic mucosal resection for superficial non-ampullary duodenal epithelial tumours, including resection depth and rate of the muscularis mucosa contained under the lesion. This single-centre retrospective cohort study conducted from January 2009 to December 2021 enrolled patients who underwent conventional endoscopic mucosal resection and underwater endoscopic mucosal resection for superficial non-ampullary duodenal epithelial tumours and investigated their clinicopathological outcomes using propensity score matching. Of the 285 superficial non-ampullary duodenal epithelial tumours, 98 conventional endoscopic mucosal resections and 187 underwater endoscopic mucosal resections were included. After propensity score matching, 64 conventional endoscopic mucosal resections and 64 underwater endoscopic mucosal resections were analysed. The R0 resection rate was significantly higher in underwater endoscopic mucosal resection cases than in conventional endoscopic mucosal resection cases (70.3% vs. 50.0%; P=0.030). In the multivariate analysis, a lesion diameter> 10mm (odds ratio 7.246; P=0.001), being in the 1st-50th treatment period (odds ratio 3.405; P=0.008), and undergoing conventional endoscopic mucosal resection (odds ratio 3.617; P=0.016) were associated with RX/R1 resection. Furthermore, in underwater endoscopic mucosal resection cases, the R0 rate was significantly higher for lesions diameter≤10mm than >10mm, and was significantly higher in the 51st-treatment period than in the 1st-50th period. Conventional endoscopic mucosal resection and underwater endoscopic mucosal resection cases showed no significant difference in resection depth and muscularis mucosa containing rate. Underwater endoscopic mucosal resection may be more acceptable than conventional endoscopic mucosal resection for superficial non-ampullary duodenal epithelial tumours ≤ 10mm. A steep early learning curve may be acquired for underwater endoscopic mucosal resection. Large multicentre prospective studies need to be conducted to confirm the effectiveness of underwater endoscopic mucosal resection.

Underwater Endoscopic Mucosal Resection Versus Conventional Endoscopic Mucosal Resection for Superficial Non-ampullary Duodenal Epithelial Tumors ≤20mm: A Systematic Review With Meta-analysis.

Underwater endoscopic mucosal resection (UEMR) is increasingly applied in the treatment of superficial non-ampullary duodenal epithelial tumors (SNADETs). This meta-analysis aimed to assess the efficacy and safety of UEMR for SNADETs ≤20mm in comparison with conventional endoscopic mucosal resection (CEMR). The following electronic databases were searched from 2012 until November 20, 2021: PubMed, Embase, Scopus, Web of Science databases, and Cochrane Library. The primary outcomes were the rates of en bloc resection and complete (R0) resection, and the secondary outcomes were procedure time, adverse events (delayed bleeding and delayed perforation), and recurrence rate. A total of 6 studies with 679 lesions (331 underwent UEMR and 348 CEMR) were included in this study. The pooled analysis showed that UMER achieves a similar en bloc resection rate (87.6 vs. 89.9%; odds ratio [OR], 1.29; 95% confidence interval [CI], 0.45 to 3.73; P =0.64; I2 =74%), a similar R0 resection rate (67.3 vs. 73.6%; OR, 1.11; 95% CI, 0.55 to 2.23; P =0.78; I2 =59%), a shorter procedure time (min) (mean difference [MD], -4.05, 95% CI: -6.40 to -1.71; P =0.0007; I2 =70%) compared with CEMR. There were no significant differences in the rates of delayed bleeding, delayed perforation, and recurrence (2.4 vs. 1.7%, 0 vs. 0.6%, 2.2 vs. 4.4%, respectively). This meta-analysis demonstrated that UEMR appears to be an effective and safe alternative to CEMR for SNADETs ≤20mm.

Underwater versus conventional endoscopic mucosal resection for colorectal lesions: An updated meta-analysis of randomized controlled trials.

Background and study aims Colorectal malignancy is a leading cause of death. Conventional endoscopic mucosal resection (CEMR) is a strategy used to resect precancerous lesions that involves injecting fluid beneath a polyp to create a gap for resection. Underwater endoscopic mucosal resection (UEMR) is a newer method that forgoes injection, instead filling the intestinal cavity with water to facilitate polyp resection. Our aim was to compare the safety and efficacy of these approaches by synthesizing the most contemporary evidence. Methods PubMed, Embase, and Cochrane libraries were searched from inception through November 11, 2022 for randomized controlled trials (RCTs) comparing UEMR and CEMR for resection of colorectal lesions. The primary outcome was the rate of en bloc resection and secondary outcomes included recurrence, procedure time, and adverse events (AEs). Results A total of 2539 studies were identified through our systematic literature search. After screening, seven RCTs with a total of 1581 polyps were included. UEMR was associated with significantly increased rates of en bloc resection (RR 1.18 [1.03, 1.35]; I 2 = 76.6%) versus conventional approaches. No significant differences were found in procedure time, recurrence, or AEs. Conclusions UEMR is a promising effective technique for removal of colorectal lesions. The most contemporary literature indicates that it improves en bloc resection rate without increasing procedure time, recurrence, or AEs (PROSPERO ID CRD42022374935).

Is endoscopic mucosal resection-precutting superior to conventional methods for removing sessile colorectal polyps?

We reviewed a study that reported a comparative analysis of the effects of endoscopic mucosal resection (EMR) precutting and conventional EMR for removing non-pedunculated, 10-20 mm sized colorectal polyps. We identified some statistical deficiencies in this study. In addition, we believe that the differences between the treatments failed to achieve significance, and therefore, further analysis is required.

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.

Underwater versus conventional endoscopic mucosal resection for colorectal lesions: a systematic review and meta-analysis of randomized clinical trials.

Conventional endoscopic mucosal resection (CEMR) is the established method for the resection of non-pedunculated colorectal lesions (NPCRL) ≥ 10mm. In the last decade, underwater endoscopic mucosal resection (UEMR) has been introduced as a potential alternative. The aim of this systematic review with meta-analysis is to compare the recurrence and safety of UEMR and CEMR by analyzing only randomized controlled trials (RCTs). We systematically searched PubMed, Cochrane Library and EMBASE until April 2023. Studies met the following inclusion criteria: (1) RCTs, (2) comparing UEMR with CEMR, (3) NPCRL ≥ 10mm, and (4) reporting the outcomes of interest. Primary outcomes were recurrence and safety. Secondary outcomes were en bloc, R0, complete resection, clipping and adverse events per type. Five RCTs were included. UEMR was associated with a lower recurrence rate (OR: 0.56; 95% CI: 0.32-0.97). Thus, the RR of recurrence was 1.7 times higher in the CEMR group (95% CI, 1.04-2.77). There was no significant difference in the pooled safety analysis. UEMR showed better en bloc resection rates (OR: 1.54; 95% CI: 1.15-2.07), but subgroup analysis showed comparable rates in lesions ≥ 20mm. R0 resection was higher in UEMR (OR: 1.72; 95% CI: 1.23-2.41). Other outcomes were not different between the 2 groups. UEMR is as safe as CEMR, with a higher overall R0 rate and a higher en bloc resection rate for lesions < 20mm, leading to a lower overall recurrence rate. The results of this meta-analysis support the widespread use of UEMR.

Efficacy and Safety of Cold Snare Endoscopic Mucosal Resection (CS-EMR) for Nonampullary Duodenal Polyps: Systematic Review and Meta-Analysis.

There is an increasing interest in cold snare endoscopic mucosal resection (CS-EMR), and studies have shown its safety and efficacy for colonic polyps. This meta-analysis aims to assess the safety and efficacy of CS-EMR for the removal of duodenal adenomas. We conducted a comprehensive literature search of several databases, from inception through February 2023, for studies that addressed outcomes of CS-EMR for nonampullary duodenal adenomas. We used the random-effects model for the statistical analysis. The weighted pooled rates were used to summarize the technical success, polyp recurrence, bleeding, and perforation events. Cochran Q test and I2 statistics adjudicated heterogeneity. Six studies were included in the analysis. In all, 178 duodenal polyps were resected using CS-EMR. The pooled rates were 95.8% (95% CI 89.1-98.5%, I2=21.5%) for technical success and 21.2% (95% CI 8.5-43.6%, I2=78%) for polyp recurrence. With regards to CS-EMR safety, the pooled rates were 4.2% (95% CI 1.6-10.5%, I2=12%) for immediate bleeding, 3.4% (95% CI 1.5-7.6%, I2=0%) for delayed bleeding, 2.8% (95% CI 1.1-6.7%, I2=0%) for perforation, and 2% (95% CL 0.5-7.5%, I2=0%) for post-polypectomy syndrome. Rates were not significantly different for large adenomas. Three studies reported data on CS-EMR and conventional EMR. Compared with conventional EMR, CS-EMR had lower odds of delayed bleeding, OR 0.11 (CI 0.02-0.62, P value 0.012, I2=0%). Our findings suggest that CS-EMR is a safe and effective strategy for the resection of nonampullary duodenal adenomas, with an acceptable recurrence rate. Data from larger randomized controlled studies are needed to validate our findings.

Safety and efficacy of underwater versus conventional endoscopic mucosal resection for colorectal polyps: Systematic review and meta-analysis of RCTs.

Background and study aims Conventional endoscopic mucosal resection (C-EMR) is limited by low en-bloc resection rates, especially for large (> 20 mm) lesions. Underwater EMR (U-EMR) has emerged as an alternative for colorectal polyps and is being shown to improve en-bloc resection rates. We conducted a systematic review and meta-analysis comparing the two techniques. Methods Multiple databases were searched through November 2022 for randomized controlled trials (RCTs) comparing outcomes of U-EMR and C-EMR for colorectal polyps. Meta-analysis was performed to determine pooled proportions and relative risks (RRs) of R0 and en-bloc resection, polyp recurrence, resection time, and adverse events. Results Seven RCTs with 1458 patients (U-EMR: 739, C-EMR: 719) were included. The pooled rate of en-bloc resection was significantly higher with U-EMR vs C-EMR, 70.17% (confidence interval [CI] 46.68-86.34) vs 58.14% (CI 31.59-80.68), respectively, RR 1.21 (CI 1.01-1.44). R0 resection rates were higher with U-EMR vs C-EMR, 58.1% (CI 29.75-81.9) vs 44.6% (CI 17.4-75.4), RR 1.25 (CI 0.99-1.6). For large polyps (> 20 mm), en-bloc resection rates were comparable between the two techniques, RR 1.24 (CI 0.83-1.84). Resection times were comparable between U-EMR and C-EMR, standardized mean difference -1.21 min (CI -2.57 to -0.16). Overall pooled rates of perforation, and immediate and delayed bleeding were comparable between U-EMR and C-EMR. Pooled rate of polyp recurrence at surveillance colonoscopy was significantly lower with U-EMR than with C-EMR, RR 0.62 (CI 0.41-0.94). Conclusions Colorectal U-EMR results in higher en-bloc resection and lower recurrence rates when compared to C-EMR. Both techniques have comparable resection times and safety profiles.

Endoscopic Management of Large Non-Pedunculated Colorectal Polyps.

Large non-pedunculated colorectal polyps ≥20 mm (LNPCPs) comprise approximately 1% of all colorectal polyps. LNPCPs more commonly contain high-grade dysplasia, covert and overt cancer. These lesions can be resected using several means, including conventional endoscopic mucosal resection (EMR), cold-snare EMR (C-EMR) and endoscopic submucosal dissection (ESD). This review aimed to provide a comprehensive, critical and objective analysis of ER techniques. Evidence-based, selective resection algorithms should be used when choosing the most appropriate technique to ensure the safe and effective removal of LNPCPs. Due to its enhanced safety and comparable efficacy, there has been a paradigm shift towards cold-snare polypectomy (CSP) for the removal of small polyps (<10 mm). This technique is now being applied to the management of LNPCPs; however, further research is required to define the optimal LNPCP subtypes to target and the viable upper size limit. Adjuvant techniques, such as thermal ablation of the resection margin, significantly reduce recurrence risk. Bleeding risk can be mitigated using through-the-scope clips to close defects in the right colon. Endoscopic surveillance is important to detect recurrence and synchronous lesions. Recurrence can be readily managed using an endoscopic approach.

Endoscopic mucosal resection: tips and tricks for gastrointestinal trainees.

Endoscopic mucosal resection (EMR) is a minimally invasive, specialized endoscopic technique that is useful in resecting superficial gastrointestinal lesions that are unable to be removed by standard polypectomy. This is typically accomplished using a submucosal injection that lifts the lesion away from the muscularis propria to allow for safe resection of the polyp, either via piecemeal or en bloc resection. Over the years, several techniques exist to perform EMR including conventional EMR or hot EMR, cold EMR and underwater EMR. Despite its established advantages and safety over conventional techniques such as surgery, the adoption of endoscopic resection (and thus the education and training of gastroenterology trainees) is lagging. The goal of this article is to offer a comprehensive review of the basic principles of colonic EMR. We review the concepts of optical diagnosis including the various polyp classification systems available to determine the polyp morphology and histology. We also discuss the technical aspects of performing colonic EMR. We also outline the common adverse events associated with EMR including bleeding, perforation, postpolypectomy syndrome, and residual or recurrent polyps, and discuss preventative measures that can be taken to mitigate adverse events. Lastly, we offer practical tips for trainees who want to undertake EMR in their clinical practice.

Feasibility of underwater endoscopic mucosal resection for endoscopic management of gastric neoplasms in patients with familial adenomatous polyposis.

Underwater endoscopic mucosal resection (UEMR) has been developed as an effective endoscopic intervention for colon, rectum, and duodenum neoplasms. However, there are no comprehensive reports regarding the stomach, and its safety and efficacy are unknown. We aimed to examine the feasibility of UEMR for gastric neoplasms in patients with familial adenomatous polyposis (FAP). We retrospectively extracted data of patients with FAP who underwent endoscopic resection (ER) for gastric neoplasms at Osaka International Cancer Institute from February 2009 to December 2018. Elevated gastric neoplasms of ≤ 20mm in diameter were extracted, and conventional endoscopic mucosal resection (CEMR) and UEMR were compared. Furthermore, outcomes after ER until March 2020 were examined. 91 endoscopically resected gastric neoplasms were extracted from 31 patients with 26 pedigrees, and 12 neoplasms underwent CEMR and 25 neoplasms underwent UEMR was compared. The procedure time was shorter for UEMR than for CEMR. There was no significant difference between en bloc resection and R0 resection rates by EMR methods. CEMR and UEMR showed postoperative hemorrhage rates of 8% and 0%, respectively. Residual/local recurrent neoplasms were identified in four lesions (4%), but additional endoscopic intervention (three UEMR and one cauterization) resulted in a local cure. UEMR was feasible in gastric neoplasms of FAP patients, especially in elevated lesions and those of ≤ 20mm in diameter.

Cold snare EMR for the removal of large duodenal adenomas.

Large (≥15mm) duodenal adenomas (DAs) are premalignant and require removal. Existing endoscopic resection techniques are compromised by serious adverse events (SAEs), most notably postprocedural bleeding (PPB) and perforation. To ameliorate these problems, we sought to evaluate the novel technique of cold snare EMR (CS-EMR) against the emerging standard of conventional EMR with thermal ablation of the postresection margin (EMR-T) for the safe and effective removal of DAs. Consecutive patients were enrolled in a single tertiary center for CS-EMR and prospectively analyzed against a previously reported cohort of EMR-T from the same center. The primary outcome was rate of SAEs. Secondary outcomes were residual or recurrent adenoma at first surveillance endoscopy (SE1) at 6 months and technical success per lesion. Between October 2019 and July 2022, a total of 50 DAs≥15mm were removed via CS-EMR (median size, 30mm [interquartile range (IQR), 19-40mm]; mean ± standard deviation [SD] patient age, 70 ± 9.2 years) compared with 54 DAs via EMR-T (median size, 30mm [IQR, 19-40mm]; mean patient age, 68 ± 12.2 years). CS-EMR had a significantly lower rate of intraprocedural bleeding (2.0% vs 37%, P< .001) and PPB (4.0% vs 16.7%, P= .036). Two cases (4.0%) of immediate perforation occurred in CS-EMR; these were recognized immediately and closed with clips without sequelae. Total SAEs (16.0% vs 16.7%, P= 1) and technical success (100% vs 100%, P= 1) were identical. Recurrence at SE1 was significantly higher with CS-EMR (24.4% vs 2.3%, P= .002). CS-EMR reduces intraprocedural bleeding and PPB. However, it may increase the risk of immediate perforation and is associated with a significantly higher rate of recurrence at SE1. Further technical refinements are required to optimize endoscopic resection techniques for DAs. (Clinical trial registration number: NCT02306603.).