Piecemeal cold snare polypectomy versus conventional endoscopic mucosal resection for large sessile serrated lesions: a retrospective comparison across two successive periods

Cold snare endoscopic mucosal resection versus standard hot technique for large flat nonpedunculated colonic lesions: a randomized controlled trial

BACKGROUNDS

 Cold snare EMR (CS-EMR) in large flat nonpedunculated colonic lesions (LFNPCLs) is an alternative to the standard EMR procedure with a better safety profile, but scientific evidence on its efficacy is unavailable. This study aimed to compare the recurrence rate between the two techniques at 6 months. Secondary aims were comparison of the safety profile and procedure-related outcomes.

METHODS

 This was a noninferiority, multicenter, open-label, randomized controlled trial of consecutive large (≥ 20 mm) LFNPCLs without suspicious features of submucosal invasion.

RESULTS

 229 patients were randomized to receive CS-EMR (n = 115) or EMR (n = 114). The median lesion size was 25 mm and 74.6 % were adenomas. The trial was stopped early by clinical consensus according to a safety monitoring board. At first surveillance colonoscopy (n = 220) the recurrence rate was significantly greater in the CS-EMR group than in the EMR group: 33.0 % vs. 16.2 % (P = 0.004) and 34.7 % vs. 14.8 % (P = 0.001) in the intention-to-treat and per-protocol analyses, respectively. According to the subgroup analysis, the recurrence rate was significantly greater after CS-EMR for LFNPCLs ≥ 30 mm (43.1 % vs. 18.2 %). There was no difference in the rate of adverse events. The use of clips was more common in the EMR group (52.6 % vs. 27.8 %).

CONCLUSIONS

 The recurrence rate of LFNPCLs after CS-EMR was significantly greater than after the standard hot technique. A similar safety profile was found between groups.

Margin thermal ablation eliminates size as a risk factor for recurrence after piecemeal endoscopic mucosal resection of large non-pedunculated colorectal polyps

BACKGROUND

Lesion size is an independent risk factor for recurrence following endoscopic mucosal resection of large (≥20 mm) non-pedunculated colorectal polyps. Post-resection margin thermal ablation (MTA) reduces the risk of recurrence. Its impact on the uncommon larger (≥40 mm) lesions is unknown.

OBJECTIVE

We sought to analyse the impact of MTA on ≥40 mm lesions in a large, prospective cohort.

DESIGN

A prospective cohort of patients with colorectal polyps ≥20 mm treated with piecemeal endoscopic mucosal resection in an expert tissue resection centre was divided into three phases: 'pre-MTA', July 2009-June 2012; 'MTA-adoption', July 2012-June 2017 and 'standardised-MTA', July 2017-July 2023. Recurrence was defined as adenomatous tissue endoscopically and/or histologically detected at the first surveillance colonoscopy. The primary outcome was the recurrence rate over the three time periods in three size groups: 20-39 mm, 40-59 mm and ≥60 mm.

RESULTS

Over 14 years until July 2023, 1872 sporadic colorectal polyps ≥20 mm in 1872 patients underwent endoscopic mucosal resection (median lesion size 35 mm (IQR 25-45mm)). Of these, 1349 patients underwent surveillance colonoscopy at a median of 6 months (IQR 4-8 months). The overall rates of recurrence in the pre-MTA, MTA-adoption and standardised-MTA phases were 13.5% (n=42/310), 12.6% (n=72/560) and 2.1% (n=10/479), respectively, (p≤0.001). When MTA was applied in the standardised-MTA phase, the rate of recurrence was the same among 20-39 mm (1.5% (3/205)), 40-59 mm (1.6% (3/190)) and ≥60 mm polyps (1.4% (1/73)) (p=1.00).

CONCLUSION

MTA negates the effect of size on the incidence of recurrence after piecemeal endoscopic mucosal resection of colorectal polyps ≥40 mm.

TRIAL REGISTRATION NUMBER

Australian Colonic Endoscopic Resection cohort (NCT01368289; NCT02000141).

Clinicopathological evaluation of the efficacy of endoscopic treatment for sessile serrated lesions comparing endoscopic mucosal resection, cold snare polypectomy, and underwater endoscopic mucosal resection

Objectives

Recently, various endoscopic treatments for colorectal polyps have been reported, including cold snare polypectomy (CSP) and underwater endoscopic mucosal resection (UEMR), in addition to EMR. However, a precise treatment strategy for sessile serrated lesions (SSL) has not been established. In this study, we analyzed the clinicopathological features of SSL resected by EMR, CSP, and UEMR to determine the most suitable treatment for SSL.

Methods

A total of 92 SSL resected via EMR (n = 11), CSP (n = 36), and UEMR (n = 45) were retrospectively enrolled between February 2021 and October 2022. To evaluate pathological findings, we examined SSL samples, which were stretched before formalin fixation and sectioned at 2-mm intervals. Primary outcomes were the R0 resection rate and thickness of submucosal (SM) tissue specimens for each treatment. In addition, we evaluated SSL with dysplasia (SSLD) and the inverted growth pattern which may affect the vertical margin.

Results

The R0 resection rate significantly differed among the three groups (EMR, 73%; CSP, 42%; UEMR, 87%, p = 0.001). The median thickness of SM tissue resected by CSP (0 µm) was significantly less than that by EMR (362 µm) and UEMR (325 µm; p < 0.001). All four SSLDs were diagnosed endoscopically. Five SSLs with inverted growth patterns were pathologically diagnosed. Of these, two SSLs with inverted growth patterns could not be diagnosed endoscopically.

Conclusions

UEMR is considered to be a suitable treatment option for SSL. CSP results were pathologically insufficient. Therefore, surveillance to evaluate local recurrence is important, and the results of further multicenter prospective studies should be referred.

Impact of margin thermal ablation after cold-forceps avulsion with snare-tip soft coagulation for nonlifting large nonpedunculated colorectal polyps

Nonlifting large nonpedunculated colorectal polyps (NL-LNPCPs) account for 15% of LNPCPs and are effectively managed by endoscopic mucosal resection (EMR) with adjunctive cold-forceps avulsion with adjuvant snare-tip soft coagulation (CAST). Recurrence rates >10% at surveillance colonoscopy are however a significant limitation. We aimed to compare the outcomes of CAST plus margin thermal ablation (MTA) versus CAST alone for NL-LNPCPs.Prospective observational data on consecutive patients with NL-LNPCPs treated by EMR and CAST at a single tertiary center were retrospectively evaluated. Two cohorts were established: the pre-MTA period (January 2012-June 2017) and the MTA period (July 2017-October 2023). The primary outcome was the residual/recurrent adenoma (RRA) rate at first surveillance colonoscopy (SC1). Secondary outcomes included the RRA rate at SC2 and adverse events.Over 142 months, 300 patients underwent EMR and CAST for LNPCP: 103 lesions pre-MTA and 197 with MTA. At SC1 and SC2, recurrence was lower in the MTA cohort compared with the pre-MTA cohort (5.0% vs. 18.8% and 0.8% vs. 10.0%, respectively; both P<0.001). Adverse events were similar between the two cohorts for deep mural injury types III-V (pre-MTA 2.9% vs. MTA 5.6%; P=0.29) and delayed bleeding (pre-MTA 8.7% vs. MTA 7.1%; P=0.49). On multivariate analysis, MTA was the only variable independently associated with a reduced likelihood of recurrence (odds ratio 0.20, 95%CI 0.07-0.54; P=0.001).For NL-LNPCPs, MTA in combination with CAST is safe and effective and reduces recurrence at SC1 in comparison with CAST alone.

Safety and Efficacy of Cold Compared With Hot Endoscopic Mucosal Resection of Large Nonpedunculated Colorectal Polyps: Systematic Review and Meta-Analysis

INTRODUCTION

Endoscopic mucosal resection (EMR) is traditionally performed using electrosurgical cautery (hot snare) to resect premalignant colorectal polyps. Recent data have suggested the superior safety of cold EMR (c-EMR), even for polyps ≥20 mm in size. We aimed to perform a systematic review and meta-analysis to assess the safety and efficacy of c-EMR compared with traditional (hot) EMR (h-EMR).

METHODS

We performed a comprehensive systematic review ending in December 2024. The primary outcome of interest was the odds of delayed bleeding for c-EMR compared with h-EMR of nonpedunculated colorectal polyps ≥20 mm in size. Odds ratios (ORs) with 95% confidence intervals (CIs) are reported. The secondary outcomes included early bleeding, perforation, and polyp recurrence. Publication bias was assessed using the classic fail-safe test. Forest plots were used to report the pooled effect estimates. Heterogeneity was assessed using I2 .

RESULTS

Our systematic review identified 1,632 unique citations, a total of 3 randomized controlled trials and 4 nonrandomized comparative studies were identified and included in the primary analyses. Four additional cohort studies were included in the secondary analyses. On random-effects modeling, c-EMR was associated with a significantly lower risk of delayed bleeding (OR 0.25, 95% CI 0.11-0.57, P = 0.001, I2 = 0%), early bleeding (OR 0.34, 95% CI 0.2-0.6, P < 0.001, I2 = 0%), and perforation (OR 0.14, 95% CI 0.04-0.51, P = 0.003, I2 = 0%) than h-EMR. c-EMR was associated with a higher rate of recurrence (OR 1.81, 95% CI 1.01-3.25, P = 0.045, I2 = 72%).

DISCUSSION

c-EMR has a superior safety profile to h-EMR for nonpedunculated colorectal polyps ≥20 mm in size, but strategies to manage the higher odds of recurrence remain essential.

Endoscopic approach to large non-pedunculated colorectal polyps

Large non-pedunculated colorectal polyps ≥20 mm (LNPCPs) constitute approximately 1% of all colorectal polyps and present a spectrum of risks, including overt and covert submucosal invasive cancer (T1 colorectal cancer (CRC)). Importantly, a curative resection may be achieved for LNPCPs with superficial T1 CRC (T1a or T1b <1000 µm into submucosa), if an enbloc R0 excision (clear margins) with favourable histology is achieved (ie, absence of high-grade tumour budding, lympho-vascular invasion, and poor differentiation). Thus, while consensus recommendations advocate for endoscopic resection as the primary treatment option for LNPCPs, thorough optical assessment is imperative for selecting the most suitable ER strategy. In this review, we highlight the critical components of optical evaluation that assist in predicting the risk of T1 CRC, including morphology (Paris and LST classifications), surface pit/vascular pattern (JNET and Kudo classifications), and lesion location. Different resection modalities, including endoscopic submucosal dissection and endoscopic mucosal resection are discussed, along with important considerations that may influence the resection strategy of choice, such as access to the LNPCP and submucosal fibrosis.

Safety and efficacy of underwater EMR for 10- to 20-mm colorectal serrated lesions (SEA CLEAR study)

BACKGROUND AND AIMS

Colorectal serrated lesions (SLs) are precursors of colorectal carcinoma via the serrated neoplasia pathway. However, the success rate of endoscopic resection of large SLs is low. Therefore, this study aimed to determine the safety and efficacy of underwater EMR (UEMR) for SLs sized 10 to 20 mm.

METHODS

This 2-center, prospective, observational study included patients with at least 1 SL sized 10 to 20 mm. We resected the SLs by UEMR and performed tattooing at the resection site. Surveillance colonoscopy was performed 12 months postoperatively to evaluate local recurrence. The primary outcome was the complete resection rate of UEMR, which was defined as en bloc resection with no serrated tissue in the 4 marginal biopsy samples and histologically negative margins.

RESULTS

UEMR was performed for 65 SLs in 58 patients, with a median lesion size of 14 mm. The en bloc, R0 resection, and complete resection rates were 87.7% (57 of 65), 61.5% (40 of 65), and 60.0% (39 of 65), respectively. Adverse events included 1 (1.5%) immediate bleeding and 1 (1.5%) delayed perforation. Surveillance colonoscopy was performed in 50 patients with 57 scars, and the rates of identification for tattoos and scars were 94.7% (54 of 57) and 100% (57 of 57), respectively. The recurrence rate was 5.3% (3 of 57), and all 3 recurrent lesions were completely resected endoscopically.

CONCLUSIONS

This 2-center prospective study demonstrated that UEMR for SLs sized 10 to 20 mm was comparable to previous conventional EMR outcomes.

The Interpretation of Magnifying Endoscopy for the Diagnosis of Colorectal Lesions

BACKGROUND

Accurate endoscopic diagnosis is crucial for determining the appropriate treatment strategy for colorectal lesions, which may include cold snare polypectomy, endoscopic mucosal resection, or endoscopic submucosal dissection.

SUMMARY

While white light imaging (WLI) serves as the basic and initial method for endoscopic diagnosis, additional techniques such as narrow band imaging (NBI), blue laser/light imaging (BLI), and magnified observation of pit patterns are necessary when WLI results are inconclusive. These advanced diagnostic methods enable precise differentiation of lesions such as adenoma, T1 cancer, and sessile serrated lesion. Furthermore, recent advancements in endoscopic systems have enhanced image clarity and detail, thereby improving diagnostic accuracy.

KEY MESSAGES

This review provides an in-depth discussion on how magnified endoscopy, utilizing the Japan NBI Expert Team (JNET) classification with NBI/BLI and pit pattern classification with chromoendoscopy, aids in the accurate diagnosis of colorectal lesions.

Optimizing duodenal tissue acquisition for mechanistic studies of duodenal ablation in type 2 diabetes

Background and study aims

Histological analysis of regular duodenal biopsies to study morphologic changes after duodenal ablation for type 2 diabetes (T2D) and metabolic syndrome is hampered by variability in tissue orientation. We designed an optimized tissue acquisition protocol using duodenal cold snare resections to create tissue microarrays (TMAs) and to allow for single-cell RNA sequencing (scRNA-seq).

Patients and methods

The open-label DIRECT study included patients undergoing an upper gastrointestinal interventional endoscopy for non-duodenal indications. All underwent one ot two single-piece duodenal cold snare resections. Endpoints were safety, adequate histological orientation of specimen and TMA, and tissue dissociation quality for scRNA-seq. The optimized tissue acquisition protocol was validated in a duodenal ablation study, EMINENT-2.

Results

In DIRECT, nine patients were included in whom a total of 16 cold snare resections were obtained. No severe adverse events (SAEs) occurred. Eighty percent of specimens and corresponding TMAs showed optimal tissue orientation. Further improvement was achieved by reducing tissue damage during endoscopic retrieval and improving histologic evaluation by eliminating ink use and pinning the tissue on cork. High-quality tissue dissociation scores for scRNA-seq were achieved in 13 of 18 samples (72%). In EMINENT-2, 38 cold snares were obtained without SAEs, histopathologic analysis showed good orientation in all samples, and dissociation scores for scRNA-seq were qualified in 35/38 (92%) samples.

Conclusions

Duodenal cold snare resection is safe and can provide high-quality tissue for optimally oriented TMAs and high-quality tissue dissociation scores for scRNA-seq (Clinicaltrials.gov, NCT06333093, NCT05984238). This approach will allow mechanistic studies about the effects of duodenal ablation on metabolic syndrome and T2D.

Efficacy and Safety of Cold Versus Hot Snare Endoscopic Mucosal Resection in Colorectal Polyp Removal: A Systematic Review and Meta-Analysis

BACKGROUND

Cold snare endoscopic mucosal resection (C-EMR) is hypothesized to offer a safety advantage over hot snare endoscopic mucosal resection (H-EMR). The primary objective of this meta-analysis is to evaluate the effectiveness and safety of C-EMR versus H-EMR for the management of colorectal lesions.

METHODS

A meta-analysis was performed to determine pooled odds ratios (ORs) for comparing outcomes between the C-EMR and H-EMR groups.

RESULTS

The pooled OR for complete resection rates were estimated at 0.70 (95% CI: 0.36-1.36, P =0.29) and en bloc rates were 0.24 (95% CI: 0.05-1.08, P =0.06) between C-EMR group and H-EMR group. The overall complete resection rate for C-EMR was 84%, and the en bloc resection rate was 57. Notably, C-EMR was associated with a significantly lower incidence of delayed bleeding. The recurrence rate of polyps was very low (2%) when treating sessile serrated polyp (SSP) lesions, but higher (23%) for non-SSP lesions. Subgroup analysis revealed minimal recurrence of polyps after using C-EMR for lesions between 10 to 20 mm and ≥20 mm.

CONCLUSIONS

This meta-analysis suggests that C-EMR could be a safer and equally effective alternative to H-EMR for resecting colorectal lesions. We recommend C-EMR as the preferred method for excising large colorectal lesions.

Efficacy of cold piecemeal EMR of medium to large adenomas compared with sessile serrated lesions

BACKGROUND AND AIMS

There is growing evidence for the role of cold piecemeal EMR (C-EMR) in the treatment of colorectal lesions ≥10 mm. However, it is unclear if C-EMR is equally efficacious for all histologic subtypes and sizes. This retrospective study compares the efficacy and safety of C-EMR in the resection of medium (10-19 mm) and large (≥20 mm) serrated and adenomatous lesions.

METHODS

A retrospective analysis was performed of Paris IIa colonic lesions resected by using a C-EMR technique over a 3.5-year period at our center.

RESULTS

C-EMR was performed for 242 lesions in 151 patients. Lesion size ranged between 10 and 50 mm, with a median size of 20 mm. Ninety-five polyps were adenomatous, with 147 sessile serrated lesions (SSLs). At 6-month surveillance colonoscopy, the combined recurrence rate was 6.2%. Adenomas ≥20 mm showed a higher rate of recurrence (16.1%) compared with large SSLs (4.1%), medium adenomas (3.0%), and medium SSLs (1.4%). There were no adverse events reported after C-EMR.

CONCLUSIONS

C-EMR seems to be less effective for the resection of large adenomas compared with medium adenomas or large SSLs. C-EMR is equally safe for all lesion sizes and histology.

Cold- versus hot-snare endoscopic mucosal resection of colorectal polyps: meta-analysis of randomized controlled trials

BACKGROUND AND AIMS

Interest in cold endoscopic mucosal resection (EMR) for colorectal polyps has been growing. We conducted a meta-analysis of randomized controlled trials to compare cold and hot EMR for colorectal polyps.

METHODS

We reviewed several databases from inception to October 6, 2024. Outcomes of interest were recurrent or residual neoplasia, en-bloc resection, incomplete resection, perforation, and intraprocedural and delayed bleeding. Pooled risk ratios (RRs) with 95% confidence intervals (CIs) were calculated by means of a random-effects model.

RESULTS

Rate of recurrent or residual neoplasia was significantly higher in the cold EMR group: RR, 2.03 (95% CI, 1.19-3.48). Rates of delayed bleeding RR, 0.42 (95% CI, 0.21-0.86) and perforation RR, 0.13 (95% CI, 0.03-0.59) were significantly lower with cold EMR. We found no significant difference in other outcomes between groups.

CONCLUSIONS

Cold EMR is associated with lower risk of delayed bleeding and perforation but higher risk of recurrent or residual neoplasia compared with hot EMR.

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

BACKGROUND AND AIMS

The 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 of recurrence at the first surveillance colonoscopy at 6 months (SC1). Whether this effect is durable to second surveillance colonoscopy (SC2) is unknown. We evaluated long-term surveillance outcomes in a cohort of LNPCPs that have undergone MTA.

METHODS

LNPCPs undergoing EMR and MTA from four academic endoscopy centres were prospectively recruited. EMR scars were evaluated at SC1 and in the absence of recurrence, SC2 colonoscopy was conducted in a further 12 months. A historical control arm was generated from LNPCPs that underwent EMR without MTA. The primary outcome was recurrence at SC2 in all LNPCPs with a recurrence-free scar at SC1.

RESULTS

1152 LNPCPs underwent EMR with complete MTA over 90 months until October 2022. 854 LNPCPs underwent SC1 with 29/854 (3.4%) LNPCPs demonstrating recurrence. 472 LNPCPs free of recurrence at SC1 underwent SC2. 260 LNPCPs with complete SC2 follow-up formed the control arm from January 2012 to May 2016. Recurrence at SC2 was significantly less in the MTA arm versus controls (1/472 (0.2%) vs 9/260 (3.5%); p<0.001)).

CONCLUSION

LNPCPs that have undergone successful EMR with MTA and are free of recurrence at SC1 are unlikely to develop recurrence in subsequent surveillance out to 2 years. Provided the colon is cleared of synchronous neoplasia, the next surveillance can be potentially extended to 3-5 years. Such an approach would reduce costs and enhance patient compliance.

Advances in Endoscopic Resection

This article provides an overview of recent advances in endoscopic resection techniques. It includes the brief overview of endoscopic submucosal dissection, regional differences in ESD indications, innovation of ESD techniques, and expansion to full-thickness resection. The article covers cold snare polypectomy for small polyps with tips, underwater endoscopic mucosal resection (U-EMR) for sessile lesions with tips and expanding role of U-EMR, and the key assistive techniques for ESD that have improved the safety and efficacy. Furthermore, it discusses the emerging field of endoscopic full-thickness resection including device-assisted and freehand exposure techniques.

International consensus on the management of large (≥20 mm) colorectal laterally spreading tumors: World Endoscopy Organization Delphi study

OBJECTIVES

There have been significant advances in the management of large (≥20 mm) laterally spreading tumors (LSTs) or nonpedunculated colorectal polyps; however, there is a lack of clear consensus on the management of these lesions with significant geographic variability especially between Eastern and Western paradigms. We aimed to provide an international consensus to better guide management and attempt to homogenize practices.

METHODS

Two experts in interventional endoscopy spearheaded an evidence-based Delphi study on behalf of the World Endoscopy Organization Colorectal Cancer Screening Committee. A steering committee comprising six members devised 51 statements, and 43 experts from 18 countries on six continents participated in a three-round voting process. The Grading of Recommendations, Assessment, Development and Evaluations tool was used to assess evidence quality and recommendation strength. Consensus was defined as ≥80% agreement (strongly agree or agree) on a 5-point Likert scale.

RESULTS

Forty-two statements reached consensus after three rounds of voting. Recommendations included: three statements on training and competency; 10 statements on preresection evaluation, including optical diagnosis, classification, and staging of LSTs; 14 statements on endoscopic resection indications and technique, including statements on en bloc and piecemeal resection decision-making; seven statements on postresection evaluation; and eight statements on postresection care.

CONCLUSIONS

An international expert consensus based on the current available evidence has been developed to guide the evaluation, resection, and follow-up of LSTs. This may provide guiding principles for the global management of these lesions and standardize current practices.

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

BACKGROUND AND AIMS

Conventional 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 a superior safety profile, cold snare EMR (C-EMR) of LNPCPs is an attractive alternative however evidence is lacking. We conducted a randomised trial to compare the efficacy and safety of C-EMR to H-EMR.

METHODS

Flat, 15-50 mm adenomatous LNPCPs were prospectively enrolled and randomly assigned to C-EMR or H-EMR with margin thermal ablation at a single tertiary centre. The primary outcome was endoscopically visible and/or histologically confirmed recurrence at 6 months surveillance colonoscopy. Secondary outcomes were clinically significant post-EMR bleeding (CSPEB), delayed perforation and technical success.

RESULTS

177 LNPCPs in 177 patients were randomised to C-EMR arm (n=87) or H-EMR (n=90). Treatment groups were equivalent for technical success 86/87 (98.9%) C-EMR versus H-EMR 90/90 (100%); p=0.31. Recurrence was significantly greater in C-EMR (16/87, 18.4% vs 1/90, 1.1%; relative risk (RR) 16.6, 95% CI 2.24 to 122; p<0.001).Delayed perforation (1/90 (1.1%) vs 0; p=0.32) only occurred in the H-EMR group. CSPEB was significantly greater in the H-EMR arm (7/90 (7.8%) vs 1/87 (1.1%); RR 6.77, 95% CI 0.85 to 53.9; p=0.034).

CONCLUSION

Compared with H-EMR, C-EMR for flat, adenomatous LNPCPs, demonstrates superior safety with equivalent technical success. However, endoscopic recurrence is significantly greater for cold snare resection and is currently a limitation of the technique.

TRIAL REGISTRATION NUMBER

NCT04138030.

Cold Versus Hot Endoscopic Mucosal Resection for Sessile Serrated Colorectal Polyps ≥10 mm: A Systematic Review and Meta-analysis

INTRODUCTION

We performed a systematic review and meta-analysis studying the efficacy and safety of cold versus hot endoscopic mucosal resection (EMR) for resection of sessile serrated polyps (SSPs) ≥10 mm.

METHODS

Multiple databases were searched until January 2023 for studies reporting outcomes of cold versus hot EMR for SSPs ≥10 mm. The primary outcome was the residual SSP rate. Secondary outcomes included technical success rate, R0 resection rate, and adverse events. We used standard meta-analysis methods using the random-effects model, and I2 % was used to assess heterogeneity.

RESULTS

Thirteen studies were included in the final analysis. In all, 1896 SSPs were included with a mean polyp size of 23.7 mm (range, 15.9 to 33). A total of 1452 SSPs were followed up for a median follow-up duration of 15.3 months (range, 6 to 37). The pooled residual SSP rate for cold EMR was 4.5% (95% CI: 1.0-17.4), and 5.1% (95% CI: 2.4-10.4) for hot EMR ( P =0.9). The pooled rates of technical success, R0 resection, immediate bleeding, and perforation were comparable. Hot EMR was significantly associated with lower piecemeal resection (59.2% vs. 99.3%, P <0.001), higher en-bloc resection (41.4% vs. 1.4%, P <0.001), and delayed bleeding rate (4% vs. 0.7%, P =0.05) compared to cold EMR.

CONCLUSIONS

Cold EMR has similar efficacy compared to hot EMR for resection of SSP ≥ 10 mm, despite limitations in piecemeal R0 resection rate reporting. Although hot EMR was associated with a higher rate of en-bloc resection, it also showed an increased risk of delayed bleeding compared to cold EMR.

Dual Channel Endoscopic Mucosal Resection

Endoscopic mucosal resection (EMR) is the recommended technique for colon polypectomy for nonpedunculated lesions that are >20 mm in size not requiring excision. Dual-channel EMR (DC-EMR) uses an endoscope with two working channels to facilitate easier submucosal injection, snare resection, and clip closure of polypectomy defects. There is also promising early literature indicating that this endoscopic modality can reduce the overall learning curve present for single-channel colonoscopy EMR. This chapter will describe the steps and techniques required to perform DC-EMR, potential complications, recommended postprocedure surveillance, and future directions.

Cold Versus Hot Snare Endoscopic Resection of Large Nonpedunculated Colorectal Polyps: Randomized Controlled German CHRONICLE Trial

BACKGROUND & AIMS

Endoscopic mucosal resection (EMR) is standard therapy for nonpedunculated colorectal polyps ≥20 mm. It has been suggested recently that polyp resection without current (cold resection) may be superior to the standard technique using cutting/coagulation current (hot resection) by reducing adverse events (AEs), but evidence from a randomized trial is missing.

METHODS

In this randomized controlled multicentric trial involving 19 centers, nonpedunculated colorectal polyps ≥20 mm were randomly assigned to cold or hot EMR. The primary outcome was major AE (eg, perforation or postendoscopic bleeding). Among secondary outcomes, major AE subcategories, postpolypectomy syndrome, and residual adenoma were most relevant.

RESULTS

Between 2021 and 2023, there were 396 polyps in 363 patients (48.2% were female) enrolled for the intention-to-treat analysis. Major AEs occurred in 1.0% of the cold group and in 7.9% of the hot group (P = .001; odds ratio [OR], 0.12; 95% CI, 0.03-0.54). Rates for perforation and postendoscopic bleeding were significantly lower in the cold group, with 0% vs 3.9% (P = .007) and 1.0% vs 4.4% (P = .040). Postpolypectomy syndrome occurred with similar frequency (3.1% vs 4.4%; P = .490). After cold resection, residual adenoma was found more frequently, with 23.7% vs 13.8% (P = .020; OR, 1.94; 95% CI, 1.12-3.38). In multivariable analysis, lesion diameter of ≥4 cm was an independent predictor both for major AEs (OR, 3.37) and residual adenoma (OR, 2.47) and high-grade dysplasia/cancer for residual adenoma (OR, 2.92).

CONCLUSIONS

Cold resection of large, nonpedunculated colorectal polyps appears to be considerably safer than hot EMR; however, at the cost of a higher residual adenoma rate. Further studies have to confirm to what extent polyp size and histology can determine an individualized approach. German Clinical Trials Registry (Deutsches Register Klinischer Studien), Number DRKS00025170.

Selection of endoscopic resection technique for large colorectal lesion treatment

PURPOSE OF REVIEW

Large nonpedunculated colorectal polyps ≥ 20 mm (LNPCPs) comprise 1% of all colorectal lesions. LNPCPs are more likely to contain advanced histology such as high-grade dysplasia and submucosal invasive cancer (SMIC). Endoscopic resection is the first-line approach for management of these lesions. Endoscopic resection options include endoscopic mucosal resection (EMR), cold-snare EMR (EMR), endoscopic submucosal dissection (ESD) and endoscopic full-thickness resection (EFTR). This review aimed to critically evaluate current endoscopic resection techniques.

RECENT FINDINGS

Evidence-based selective resection algorithms should inform the most appropriate endoscopic resection technique. Most LNPCPs are removed by conventional EMR but there has been a trend toward C-EMR for endoscopic resection of LNPCPs. More high-quality trials are required to better define the limitations of C-EMR. Advances in our understanding of ESD technique, has clarified its role within the colorectum. More recently, the development of a full thickness resection device (FTRD) has allowed the curative endoscopic resection of select lesions.

SUMMARY

Endoscopic resection should be regarded as the principle approach for all LNPCPs. Underpinned by high-quality research, endoscopic resection has become more nuanced, leading to improved patient outcomes.

Cold Endoscopic Mucosal Resection (c-EMR) of Nonpedunculated Colorectal Polyps ≥20 mm: A Systematic Review and Meta-analysis

BACKGROUND

There is increasing evidence that cold endoscopic mucosal resection (c-EMR) can effectively treat large colorectal polyps. We aim to appraise the current literature and evaluate outcomes following c-EMR for nonpedunculated colonic polyps ≥20 mm.

METHODS

Major databases were searched. Primary outcomes included recurrence rate and adverse events. Meta-analysis was performed using a random-effects model.

RESULTS

Nine articles were included in the final analysis, which included 817 patients and 1077 colorectal polyps. Average polyp size was 28.8 (±5.1) mm. The pooled recurrence rate of polyps of any histology at 4 to 6 months was 21.0% (95% CI: 9.0%-32.0%, P <0.001, I2 =97.3, P <0.001). Subgroup analysis showed that recurrence was 10% for proximal lesions (95% CI: 0.0%-20.0%, P =0.054, I2 =93.7%, P =0.054) and 9% for distal lesions (95% CI: 2.0%-21.0%, P =0.114, I2 =95.8%, P =0.114). Furthermore, subgroup analysis showed that recurrence was 12% for adenoma (95% CI: 4.0%-19.0%, P =0.003, I2 =98.0%, P =0.003), and 3% for sessile serrated polyps (95% CI: 1.0%-5.0%, P =0.002, I2 =34.4%, P =0.002). Post-polypectomy bleeding occurred in 1% (n=8/817) of patients, whereas abdominal pain occurred in 0.2% (n=2/817) of patients.

CONCLUSIONS

C-EMR for nonpedunculated colorectal polyps ≥20 mm shows an excellent safety profile with a very low rate of delayed bleeding as well as significantly less recurrence for sessile serrated polyps than adenomas.

Endoscopic Resection of Neoplasia in the Lower GI Tract: A Clinical Algorithm

Background

Colorectal cancer is a highly prevalent malignancy and a significant driver of cancer mortality and health-related expenditure worldwide. Polyp removal reduces the incidence and mortality of colorectal cancer. In 2024, endoscopists have an array of resection modalities at their disposal. Each technique requires a unique skillset and has individual advantages and limitations. Consequently, resection in the colorectum requires an evidence-based algorithm approach that considers these factors.

Summary

A literature review of endoscopic resection for colonic neoplasia was conducted. Best supporting scientific evidence was summarized for the endoscopic resection of diminutive polyps, large ≥20 mm lesions and polyps containing invasive cancer. Factors including resection modality, complications and lesion selection were explored to inform an algorithm approach to colorectal resection.

Key Messages

Endoscopic resection in the colorectum is not a one-size-fits-all approach. Detailed understanding of polyp size, location, morphology and predicted histology are critical factors that inform appropriate endoscopic resection practice.

Large non-pedunculated colorectal polyp management: The elephant in the room

Minimally invasive innovations have transformed coloproctology. Specific to colorectal cancer (CRC), there has been a shift towards less invasive surgical techniques and use of endoscopic resection as an alternative for low risk T1 CRC. The role of endoscopic resection is however much more extensive: It is now considered the first line management strategy for most large (≥ 20 mm) non-pedunculated colorectal polyps, the majority of which are benign. This is due to the well-established efficacy, safety, and cost-effectiveness of endoscopic techniques compared to surgery. Multiple endoscopic modalities now exist with distinct risk-benefit profiles and their outcomes are further improved by site-specific technical modifications, auxiliary techniques, and adverse event mitigation strategies. Endoscopic capacity continues to evolve with emerging endoscopic techniques and expanding applications, particularly in the confines of a multi-disciplinary setting.

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.

Precision endoscopy in colorectal polyps' characterization and planning of endoscopic therapy

Precision endoscopy in the management of colorectal polyps and early colorectal cancer has emerged as the standard of care. It includes optical characterization of polyps and estimation of submucosal invasion depth of large nonpedunculated colorectal polyps to select the appropriate endoscopic resection modality. Over time, several imaging modalities have been implemented in endoscopic practice to improve optical performance. Among these, image-enhanced endoscopy systems and magnification endoscopy represent now well-established tools. New advanced technologies, such as endocytoscopy and confocal laser endomicroscopy, have recently shown promising results in predicting the histology of colorectal polyps. In recent years, artificial intelligence has continued to enhance endoscopic performance in the characterization of colorectal polyps, overcoming the limitations of other imaging modes. In this review we retrace the path of precision endoscopy, analyzing the yield of various endoscopic imaging techniques in personalizing management of colorectal polyps and early colorectal cancer.

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

BACKGROUND

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.

METHODS

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.

RESULTS

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.

CONCLUSIONS

The findings of this meta-analysis suggest that C-EMR has similar efficacy and safety to CSP, but significantly increases the procedure time.

PROSPERO

CRD42023439605.

Comparison of cold snare polypectomy for sessile serrated lesions ≥10 mm between experienced and trainee endoscopists: A propensity score matching cohort study

Objectives

Previous studies of cold snare polypectomy (CSP) for sessile serrated lesions (SSLs) ≥10 mm were performed by experienced endoscopists, and therefore their skills might have significantly influenced results. In this study, we compared the efficacy and safety of CSP for SSLs ≥10 mm between experienced and trainee endoscopists.

Methods

In a 1:1 propensity score matched retrospective cohort study, we compared the complete resection rate, en-bloc resection rate, adverse event rate, and procedure time between experienced and trainee groups. Thirteen endoscopists performed CSP, and we defined the experienced group as endoscopists with board certification from the Japan Gastroenterological Endoscopy Society.

Results

We examined 616 lesions with SSLs ≥10 mm resected by CSP between February 2018 and May 2022. We excluded 61 lesions from the analysis because they had simultaneously undergone hot snare polypectomy (n = 57) or had been taken over by experienced endoscopists from trainees in the CSP procedure (n = 4). Finally, we identified 217 propensity score-matched pairs (n = 434). Between experienced and trainee groups, the results were complete resection rate (100 vs. 100%; p = 1.00), en-bloc resection rate (73.2 vs. 75.6%; p = 0.24), adverse event rate (3.2 vs. 2.8%; p = 0.77), or procedure time (6.2 vs. 5.9 min; p = 0.64).

Conclusions

We have demonstrated the safety and efficacy of CSP for SSLs ≥10 mm performed by experienced and trainee endoscopists.

Advantage of magnifying narrow-band imaging for the diagnosis of colorectal neoplasia associated with sessile serrated lesions

Objectives

This study aimed to extract endoscopic findings for diagnosing colorectal neoplasia associated with sessile serrated lesions (SSLs), which are of significant interest.

Methods

To compare the magnifying narrow-band imaging (NBI) findings with microscopic morphology, we classified SSLs into two groups: Group A SSLs included the majority of uniform SSLs and any dysplasia other than that classified as group B SSLs. Group B SSLs included SSLs with intramucosal and invasive carcinoma. We also quantitatively assessed visible vessels using ImageJ software.

Results

This study included 47 patients with 50 group B SSLs who underwent endoscopic resection between 2012 and 2020. The results were retrospectively compared with those of 237 patients with 311 group A SSLs that underwent endoscopic resection. Using conventional white-light endoscopy, significantly more group B SSLs had uneven shapes and some reddening compared to group A SSLs. The diagnostic odds ratios for group B SSLs were as follows: lesions with a diameter ≥10 mm, 9.76; uneven shape, 3.79; reddening, 15.46; and visible vessels with NBI, 11.32. Regarding visible vessels with NBI, the specificity and diagnostic accuracy for group B SSLs were 94.9% and 93.1%, respectively. The percentage of the vascular tonal area of NBI images was significantly larger for group B SSLs than for group A SSLs (3.97% vs. 0.29%; p < 0.01).

Conclusions

SSLs with reddening and/or a diameter ≥10 mm are suspected to contain cancerous components. Moreover, visible vessels observed using magnifying NBI can serve as objective indicators for diagnosing SSLs with cancerous components with a high degree of accuracy.

Endoscopic resection of large non-pedunculated colorectal polyps: current standards of treatment

Colorectal cancer is a significant public health concern, and large non-pedunculated colorectal polyps pose a substantial risk for malignancy and incomplete resection, which may lead to interval cancer. The choice of resection technique is influenced by various factors, including polyp size, morphology, location, submucosal invasion depth and endoscopist expertise. For non-cancerous superficial large non-pedunculated polyps, conventional hot or cold snare polypectomy, endoscopic mucosal resection and endoscopic submucosal dissection are common techniques for non-surgical therapeutic endoscopic resection of these polyps. This manuscript provides a comprehensive review of literature on current endoscopic resection techniques for large non-pedunculated colorectal polyps, emphasising indications, advantages, limitations and outcomes.

Cold EMR vs. Hot EMR for the removal of sessile serrated polyps larger than 10 mm: a systematic review and meta-analysis

BACKGROUND

Endoscopic mucosal resection (EMR) appears to be a promising technique for the removal of sessile serrated polyps (SSPs) ≥ 10 mm. To assess the effectiveness and safety of EMR for removing SSPs ≥ 10 mm, we conducted this systematic review and meta-analysis.

METHODS

We conducted a thorough search of Embase, PubMed, Cochrane, and Web of Science databases for relevant studies reporting on EMR of SSPs ≥ 10 mm, up until December 2023. Our primary endpoints of interest were rates of technical success, residual SSPs, and adverse events (AE).

RESULTS

Our search identified 426 articles, of which 14 studies with 2262 SSPs were included for analysis. The rates of technical success, AEs, and residual SSPs were 100%, 2.0%, and 3.1%, respectively. Subgroup analysis showed that the technical success rates were the same for polyps 10-19 and 20 mm, and en-bloc and piecemeal resection. Residual SSPs rates were similar in en-bloc and piecemeal resection, but much lower in cold EMR (1.0% vs. 4.2%, P = 0.034). AEs rates were reduced in cold EMR compared to hot EMR (0% vs. 2.9%, P = 0.168), in polyps 10-19 mm compared to 20 mm (0% vs. 4.1%, P = 0.255), and in piecemeal resection compared to en-bloc (0% vs. 0.7%, P = 0.169).

CONCLUSIONS

EMR is an effective and safe technique for removing SSPs ≥ 10 mm. The therapeutic effect of cold EMR is superior to that of hot EMR, with a lower incidence of adverse effects.

PROSPERO REGISTRATION NUMBER

CRD42023388959.

AGA Clinical Practice Update on Appropriate and Tailored Polypectomy: Expert Review

DESCRIPTION

In this Clinical Practice Update (CPU), we provide guidance on the appropriate use of different polypectomy techniques. We focus on polyps <2 cm in size that are most commonly encountered by the practicing endoscopist, including use of classification systems to characterize polyps and various polypectomy methods. We review characteristics of polyps that require complex polypectomy techniques and provide guidance on which types of polyps require more advanced management by a therapeutic endoscopist or surgeon. This CPU does not provide a detailed review of complex polypectomy techniques, such as endoscopic submucosal dissection, which should only be performed by endoscopists with advanced training.

METHODS

This expert review was commissioned and approved by the American Gastroenterological Association (AGA) Institute CPU Committee and the AGA Governing Board to provide timely guidance on a topic of high clinical importance to the AGA membership, and underwent internal peer review by the CPU Committee and external peer review through standard procedures of Clinical Gastroenterology and Hepatology. These Best Practice Advice statements were drawn from a review of the published literature and from expert opinion. Because systematic reviews were not performed, these Best Practice Advice statements do not carry formal ratings regarding the quality of evidence or strength of the presented considerations. BEST PRACTICE ADVICE 1: A structured visual assessment using high-definition white light and/or electronic chromoendoscopy and with photodocumentation should be conducted for all polyps found during routine colonoscopy. Closely inspect colorectal polyps for features of submucosally invasive cancer. BEST PRACTICE ADVICE 2: Use cold snare polypectomy for polyps <10 mm in size. Cold forceps polypectomy can alternatively be used for 1- to 3-mm polyps where cold snare polypectomy is technically difficult. BEST PRACTICE ADVICE 3: Do not use hot forceps polypectomy. BEST PRACTICE ADVICE 4: Clinicians should be familiar with various techniques, such as cold and hot snare polypectomy and endoscopic mucosal resection, to ensure effective, safe, and optimal resection of intermediate-size polyps (10-19 mm). BEST PRACTICE ADVICE 5: Consider using lifting agents or underwater endoscopic mucosal resection for removal of sessile polyps 10-19 mm in size. BEST PRACTICE ADVICE 6: Serrated polyps should be resected using cold resection techniques. Submucosal injection may be helpful for polyps >10 mm if margins cannot be well delineated. BEST PRACTICE ADVICE 7: Use hot snare polypectomy to remove pedunculated lesions >10 mm in size. BEST PRACTICE ADVICE 8: Do not routinely use clips to close resection sites for polyps <20 mm. BEST PRACTICE ADVICE 9: Refer patients with polyps to endoscopic referral centers in the context of size ≥20 mm, challenging polypectomy location, or recurrent polyp at a prior polypectomy site. BEST PRACTICE ADVICE 10: Tattoo lesions that may need future localization at endoscopy or surgery. Tattoos should be placed in a location that will not interfere with subsequent attempts at endoscopic resection. BEST PRACTICE ADVICE 11: Refer patients with nonpedunculated polyps with clear evidence of submucosally invasive cancer for surgical evaluation. BEST PRACTICE ADVICE 12: Understand the endoscopy suite's electrosurgical generator settings appropriate for polypectomy or postpolypectomy thermal techniques.

Geometry of cold snare polypectomy and risk of incomplete resection

BACKGROUND

Cold snare polypectomy (CSP) is safer than and equally efficacious as hot snare polypectomy (HSP) for the removal of small (<10mm) colorectal polyps. The maximum polyp size that can be effectively managed by piecemeal CSP (p-CSP) without an excessive burden of recurrence is unknown.

METHODS

Resection error risks (RERs), defined as the estimated likelihood of incomplete removal of adenomatous tissue for a single snare resection pass, for CSP and HSP were calculated, based on an incomplete resection rate. Polyp area, snare size, estimated number of resections, and optimal resection defect area were modeled. Overall risk of incomplete resection (RIR) was defined as RIR=1 - (1 - p)n, where p is the RER and n the number of resections.

RESULTS

A 40-mm polyp has a four times greater area than a 20-mm polyp (314.16mm2 vs. 1256.64mm2), and requires three times more resections (11 vs. 33, respectively, assuming 8-mm piecemeal resection pieces for p-CSP). RIRs for a 40-mm polyp by HSP and p-CSP were 15.1%-23% and 40.74%-60.60% respectively.

CONCLUSION

RER is more important with p-CSP than with HSP. The number of resections, n, and consequently RIR increases with increasing polyp size. Given the overwhelming safety of CSP, specific techniques to minimize the RER should be studied and developed.

Endoscopic En Bloc Versus Piecemeal Resection of Large Nonpedunculated Colonic Adenomas : A Randomized Comparative Trial

BACKGROUND

Endoscopic resection of adenomas prevents colorectal cancer, but the optimal technique for larger lesions is controversial. Piecemeal endoscopic mucosal resection (EMR) has a low adverse event (AE) rate but a variable recurrence rate necessitating early follow-up. Endoscopic submucosal dissection (ESD) can reduce recurrence but may increase AEs.

OBJECTIVE

To compare ESD and EMR for large colonic adenomas.

DESIGN

Participant-masked, parallel-group, superiority, randomized controlled trial. (ClinicalTrials.gov: NCT03962868).

SETTING

Multicenter study involving 6 French referral centers from November 2019 to February 2021.

PARTICIPANTS

Patients with large (≥25 mm) benign colonic lesions referred for resection.

INTERVENTION

The patients were randomly assigned by computer 1:1 (stratification by lesion location and center) to ESD or EMR.

MEASUREMENTS

The primary end point was 6-month local recurrence (neoplastic tissue on endoscopic assessment and scar biopsy). The secondary end points were technical failure, en bloc R0 resection, and cumulative AEs.

RESULTS

In total, 360 patients were randomly assigned to ESD (n = 178) or EMR (n = 182). In the primary analysis set (n = 318 lesions in 318 patients), recurrence occurred after 1 of 161 ESDs (0.6%) and 8 of 157 EMRs (5.1%) (relative risk, 0.12 [95% CI, 0.01 to 0.96]). No recurrence occurred in R0-resected cases (90%) after ESD. The AEs occurred more often after ESD than EMR (35.6% vs. 24.5%, respectively; relative risk, 1.4 [CI, 1.0 to 2.0]).

LIMITATION

Procedures were performed under general anesthesia during hospitalization in accordance with the French health system.

CONCLUSION

Compared with EMR, ESD reduces the 6-month recurrence rate, obviating the need for systematic early follow-up colonoscopy at the cost of more AEs.

PRIMARY FUNDING SOURCE

French Ministry of Health.

Local recurrence rates after resection of large colorectal serrated lesions with or without margin thermal ablation

INTRODUCTION

Serrated lesions (SLs) including traditional serrated adenomas (TSA), large hyperplastic polyps (HP) and sessile serrated lesions (SSLs) are associated with high incomplete resection rates. Margin ablation combined with EMR (EMR-T) has become routine to reduce local recurrence while cold snare polypectomy (CSP) is becoming recognized as equally effective for large SLs. Our aim was to evaluate local recurrence rates (LRR) and the use of margin ablation in preventing recurrence in a retrospective cohort study.

METHODS

Patients undergoing resection of ≥15 mm colorectal SLs from 2010-2022 were identified through a pathology database and electronic medical records search. Hereditary CRC syndromes, first follow-up > 18 months or no follow-up, surgical resection were excluded. Primary outcome was LRRs (either histologic or visual) during the first 18-month follow-up. Secondary outcomes were LRRs according to size, and resection technique.

RESULTS

191 polyps in 170 patients were resected (59.8% women; mean age, 65 years). The mean size of polyps was 22.4 mm, with 107 (56.0%) ≥20 mm. 99 polyps were resected with EMR, 39 with EMR-T, and 26 with CSP. Mean first surveillance was 8.2 mo. Overall LRR was 18.8% (36/191) (16.8% for ≥20 mm, 17.9% for ≥30 mm). LRR was significantly lower after EMR-T when compared with EMR (5.1% vs. 23.2%; p = 0.013) or CSP (5.1% vs. 23.1%; p = 0.031). There was no difference in LRR between EMR without margin ablation and CSP (p = 0.987).

CONCLUSION

The local recurrence rate for SLs ≥15 mm is high with 18.8% overall recurrence. EMR with thermal ablation of the margins is superior to both no ablation and CSP in reducing LRRs.

A novel tool for case selection in endoscopic mucosal resection training

BACKGROUND

 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.

METHODS

 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.

RESULTS

 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.

CONCLUSIONS

 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.

Cold snare endoscopic mucosal resection for colon polyps: a systematic review and meta-analysis

BACKGROUND

 Cold snare endoscopic mucosal resection (CS-EMR) can reduce the risks associated with electrocautery during colon polyp resection. Data on efficacy are variable. This systematic review and meta-analysis aimed to estimate the pooled efficacy and safety rates of CS-EMR.

METHODS

 We conducted a comprehensive literature search of multiple databases, from inception to March 2023, for studies addressing outcomes of CS-EMR for colon polyps. The weighted pooled estimates with 95 %CIs were calculated using the random effects model. I2 statistics were used to evaluate heterogeneity.

RESULTS

 4137 articles were reviewed, and 16 studies, including 2592 polyps in 1922 patients (51.4 % female), were included. Overall, 54.4 % of polyps were adenomas, 45 % were sessile serrated lesions (SSLs), and 0.6 % were invasive carcinomas. Polyp recurrence after CS-EMR was 6.7 % (95 %CI 2.4 %-17.4 %, I2  = 94 %). The recurrence rate was 12.3 % (95 %CI 3.4 %-35.7 %, I2  = 94 %) for polyps ≥ 20 mm, 17.1 % (95 %CI 4.6 %-46.7 %, I2  = 93 %) for adenomas, and 5.7 % (95 %CI 3.2 %-9.9 %, I2  = 50 %) for SSLs. The pooled intraprocedural bleeding rate was 2.6 % (95 %CI 1.5 %-4.5 %, I2  = 51 %), the delayed bleeding rate was 1.5 % (95 %CI 0.8 %-2.7 %, I2  = 18 %), and no perforations or post-polypectomy syndromes were reported, with estimated rates of 0.6 % (95 %CI 0.3 %-1.3 %, I2  = 0 %) and 0.6 % (95 %CI 0.3 %-1.4 %, I2  = 0 %), respectively.

CONCLUSION

 CS-EMR demonstrated an excellent safety profile for colon polyps, with variable recurrence rates based on polyp size and histology. Large prospective studies are needed to validate these findings.

Cold snare resection for non-ampullary sporadic duodenal adenomas: systematic review and meta-analysis

Background and study aims The role of cold snare polypectomy (CSP) in curative resection of non-ampullary sporadic duodenal adenomas (NASDA) is debated. We conducted a systematic review and meta-analysis to investigate the efficacy and safety of CSP for NASDA. Patients and methods In this systematic review and meta-analysis, we identified published series of patients with CSP for NASDA by searching PubMed and Google Scholar, which resulted in six papers (205 lesions). The main outcome was the rate of local remission after repeated CSP, the secondary outcomes were rates of local remission at first control and rates for delayed bleeding and immediate perforations. We computed the weighted summary proportions under the fixed and random effects model. Results The pooled proportion of local remission after repeated CSP was 88% (95% confidence interval [CI] 57%-100%). The pooled proportion of local remission at first control was 81% (95% CI 55%-98%), the pooled proportion of delayed bleeding was 1% (95% CI 0%-4%) and the pooled proportion of immediate perforation was 0% (95% CI 0%-2%). Conclusions Our meta-analysis suggests that CSP should be considered as the first-line therapy for NASDA.

Endoscopic resection-related colorectal strictures: risk factors, management, and long-term outcomes

INTRODUCTION

Colorectal strictures related to endoscopic resection (ER) of large nonpedunculated colorectal polyps (LNPCPs) may be problematic. Data on prevalence, risk factors, and management are limited. We report a prospective study of colorectal strictures following ER and describe our approach to management.

METHODS

We analyzed prospectively collected data over 150 months, until June 2021, for patients who underwent ER for LNPCPs ≥ 40 mm. The ER defect size was graded as < 60 %, 60 %-89 %, or ≥ 90 % of the luminal circumference. Strictures were considered "severe" if patients experienced obstructive symptoms, "moderate" if an adult colonoscope could not pass the stenosis, or "mild" if there was resistance on successful passage. Primary outcomes included stricture prevalence, risk factors, and management.

RESULTS

916 LNPCPs ≥ 40 mm in 916 patients were included (median age 69 years, interquartile range 61-76 years, male sex 484 [52.8 %]). The primary resection modality was endoscopic mucosal resection in 859 (93.8 %). Risk of stricture formation with an ER defect ≥ 90 %, 60 %-89 %, and < 60 % was 74.2 % (23/31), 25.0 % (22/88), and 0.8 % (6 /797), respectively. Severe strictures only occurred with ER defects ≥ 90 % (22.6 %, 7/31). Defects < 60 % conferred low risk of only mild strictures (0.8 %, 6/797). Severe strictures required earlier (median 0.9 vs. 4.9 months; P = 0.01) and more frequent (median 3 vs. 2; P = 0.02) balloon dilations than moderate strictures.

CONCLUSION

Most patients with ER defects ≥ 90 % of luminal circumference developed strictures, many of which were severe and required early balloon dilation. There was minimal risk with ER defects < 60 %.

Pure Cut or Endocut for Biliary Sphincterotomy? A Multicenter Randomized Clinical Trial

INTRODUCTION

Adverse events (AE) after endoscopic retrograde cholangiopancreatography (ERCP) are not uncommon and post-ERCP acute pancreatitis (PEP) is the most important one. Thermal injury from biliary sphincterotomy may play an important role and trigger PEP or bleeding. Therefore, this study evaluated the outcomes of 2 electric current modes used during biliary sphincterotomy.

METHODS

From October 2019 to August 2021, consecutive patients with native papilla undergoing ERCP with biliary sphincterotomy were randomized to either the pure cut or endocut after cannulation. The primary outcome was PEP incidence. Secondary outcomes included intraprocedural and delayed bleeding, infection, and perforation.

RESULTS

A total of 550 patients were randomized (272 pure cut and 278 endocut). The overall PEP rate was 4.0% and significantly higher in the endocut group (5.8% vs 2.2%, P = 0.034). Univariate analysis revealed >5 attempts ( P = 0.004) and endocut mode ( P = 0.034) as risk factors for PEP. Multivariate analysis revealed >5 attempts ( P = 0.005) and a trend for endocut mode as risk factors for PEP ( P = 0.052). Intraprocedural bleeding occurred more often with pure cut ( P = 0.018), but all cases were controlled endoscopically during the ERCP. Delayed bleeding was more frequent with endocut ( P = 0.047). There was no difference in perforation ( P = 1.0) or infection ( P = 0.4999) between the groups.

DISCUSSION

Endocut mode may increase thermal injury leading to higher rates of PEP and delayed bleeding, whereas pure cut is associated with increased intraprocedural bleeding without clinical repercussion. The electric current mode is not related to perforation or infection. Further RCT assessing the impact of electric current on AE with overlapping preventive measures such as rectal nonsteroidal anti-inflammatory drugs and hyperhydration are needed. The study was submitted to the Brazilian Clinical Trials Platform ( http://www.ensaiosclinicos.gov.br ) under the registry number RBR-5d27tn.

Sessile serrated lesions with dysplasia: is it possible to nip them in the bud?

The serrated neoplasia pathway constitutes an "alternative route" to colorectal cancer (CRC), and sessile serrated lesions with dysplasia (SSLDs) are an intermediate step between sessile serrated lesions (SSLs) and invasive CRC in this pathway. While SSLs show indolent growth before becoming dysplastic (> 10-15 years), SSLDs are considered to rapidly progress to either immunogenic microsatellite instable-high (MSI-H) CRC (presumably 75% of cases) or mesenchymal microsatellite stable (MSS) CRC. Their flat shapes and the relatively short window of this intermediate state make it difficult to detect and diagnose SSLDs; thus, these lesions are potent precursors of post-colonoscopy/interval cancers. Confusing terminology and the lack of longitudinal observation data of serrated polyps have hampered the accumulation of knowledge about SSLDs; however, a growing body of evidence has started to clarify their characteristics and biology. Together with recent efforts to incorporate terminology, histological studies of SSLDs have identified distinct dysplastic patterns and revealed alterations in the tumor microenvironment (TME). Molecular studies at the single-cell level have identified distinct gene alterations in both the epithelium and the TME. Mouse serrated tumor models have demonstrated the importance of TME in disease progression. Advances in colonoscopy provide clues to distinguish pre-malignant from non-malignant-SSLs. Recent progress in all aspects of the field has enhanced our understanding of the biology of SSLDs. The aim of this review article was to assess the current knowledge of SSLDs and highlight their clinical implications.

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.

[Interventional endoscopy in gastroenterology]

Essential innovations in interventional endoscopy have significantly broadened the treatment armamentarium in gastroenterology. The treatment and complication management of intraepithelial neoplasms and early forms of cancer are increasingly being primarily addressed endoscopically. In cases of endoluminal lesions with no risk of lymph node or distant metastases, endoscopic mucosal resection and endoscopic submucosal dissection have become established as standards. For broad-based adenomas, coagulation of the resection margins should be performed in the case of a piecemeal resection. Submucosal lesions can be reached and resected by tunneling techniques. Peroral endoscopic myotomy in cases of achalasia is a new treatment option for hypertensive and hypercontractile motility disorders. In addition, endoscopic myotomy for gastroparesis has shown very promising results. In this article, new resection techniques and so-called third space endoscopy are presented and critically discussed.

Cold resection for colorectal polyps: where we are and where we are going?

INTRODUCTION

Endoscopic resection of colonic precancerous lesions has been demonstrated to significantly decrease colorectal cancer (CRC) incidence and mortality. Among resection techniques, cold snare polypectomy (CSP) has been shown as a highly feasible, effective and safe option and is widely used in clinical practice, being regarded as the first-line technique for removal of small and diminutive colorectal polyps. On the other hand, conventional hot snare polypectomy (HSP) and endoscopic mucosal resection (EMR), namely the gold standard treatments for larger polyps, may be occasionally associated to complications due to electrocautery injury.

AREAS COVERED

To overcome these shortcomings of electrocautery-based resection techniques, in the last few years CSP has been increasingly assessed as a treatment option for additional indications, with a focus on nonpedunculated colorectal polyps ≥10 mm.

EXPERT OPINION

This review aims to present current and widened indications of CSP discussing the latest findings from the most remarkable studies, with an insight into technical issues, novelties and potential advances in the near future.

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

BACKGROUND

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.

AIM

To compare the treatment outcomes of bipolar polypectomy with hot snare polypectomy (HSP) to those with endoscopic mucosal resection (EMR).

METHODS

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.

RESULTS

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.

CONCLUSION

Using bipolar snare, ER of nonpedunculated 10–15 mm colorectal lesions may be performed safely and effectively, even without submucosal injection.

Curriculum for training in endoscopic mucosal resection in the colon: European Society of Gastrointestinal Endoscopy (ESGE) Position Statement

Endoscopic mucosal resection (EMR) is the standard of care for the complete removal of large (≥ 10 mm) nonpedunculated colorectal polyps (LNPCPs). Increased detection of LNPCPs owing to screening colonoscopy, plus high observed rates of incomplete resection and need for surgery call for a standardized approach to training in EMR. 1 : Trainees in EMR should have achieved basic competence in diagnostic colonoscopy, < 10-mm polypectomy, pedunculated polypectomy, and common methods of gastrointestinal endoscopic hemostasis. The role of formal training courses is emphasized. Training may then commence in vivo under the direct supervision of a trainer. 2 : Endoscopy units training endoscopists in EMR should have specific processes in place to support and facilitate training. 3: A trained EMR practitioner should have mastered theoretical knowledge including how to assess an LNPCP for risk of submucosal invasion, how to interpret the potential difficulty of a particular EMR procedure, how to decide whether to remove a particular LNPCP en bloc or piecemeal, whether the risks of electrosurgical energy can be avoided for a particular LNPCP, the different devices required for EMR, management of adverse events, and interpretation of reports provided by histopathologists. 4: Trained EMR practitioners should be familiar with the patient consent process for EMR. 5: The development of endoscopic non-technical skills (ENTS) and team interaction are important for trainees in EMR. 6: Differences in recommended technique exist between EMR performed with and without electrosurgical energy. Common to both is a standardized technique based upon dynamic injection, controlled and precise snare placement, safety checks prior to the application of tissue transection (cold snare) or electrosurgical energy (hot snare), and interpretation of the post-EMR resection defect. 7: A trained EMR practitioner must be able to manage adverse events associated with EMR including intraprocedural bleeding and perforation, and post-procedural bleeding. Delayed perforation should be avoided by correct interpretation of the post-EMR defect and treatment of deep mural injury. 8: A trained EMR practitioner must be able to communicate EMR procedural findings to patients and provide them with a plan in case of adverse events after discharge and a follow-up plan. 9: A trained EMR practitioner must be able to detect and interrogate a post-endoscopic resection scar for residual or recurrent adenoma and apply treatment if necessary. 10: Prior to independent practice, a minimum of 30 EMR procedures should be performed, culminating in a trainer-guided assessment of competency using a validated assessment tool, taking account of procedural difficulty (e. g. using the SMSA polyp score). 11: Trained practitioners should log their key performance indicators (KPIs) of polypectomy during independent practice. A guide for target KPIs is provided in this document.