Endoscopic Removal of Colorectal Lesions-Recommendations by the US Multi-Society Task Force on Colorectal Cancer

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.

Endoscopic Mucosal Resection and Endoscopic Submucosal Dissection

Up to 15% of colorectal polyps are amenable for conventional polypectomy. Advanced endoscopic resection techniques are introduced for the treatment of those polyps. They provide higher en bloc resection rates compared with conventional techniques, while helping patients to avoid the complications of surgery. Note that 20 mm is considered as the largest size of a polyp that can be resected by polypectomy or endoscopic mucosal resection (EMR) in an en bloc fashion. Endoscopic submucosal dissection (ESD) is recommended for polyps larger than 20 mm. Intramucosal carcinomas and carcinomas with limited submucosal invasion can also be resected with ESD. EMR is snare resection of a polyp following submucosal injection and elevation. ESD involves several steps such as marking, submucosal injection, incision, and dissection. Bleeding and perforation are the most common complications following advanced endoscopic procedures, which can be treated with coagulation and endoscopic clipping. En bloc resection rates range from 44.5 to 63% for EMR and from 87.9 to 96% for ESD. Recurrence rates following EMR and ESD are 7.4 to 17% and 0.9 to 2%, respectively. ESD is considered enough for the treatment of invasive carcinomas in the presence of submucosal invasion less than 1000 μm, absence of lymphovascular invasion, well-moderate histological differentiation, low-grade tumor budding, and negative resection margins.

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.

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.

Cold sub-mucosal injection versus traditional cold snare polypectomy for diminutive and small colorectal polyps: A systematic review and meta-analysis

BACKGROUND

The guidelines recommend conventional cold snare polypectomy (C-CSP) for diminutive and small colorectal polyps (≤ 10 mm). However, it remains unclear whether CSP with sub-mucosal injection (SI-CSP) achieves comparable efficacy to C-CSP for managing these lesions. This study compares SI-CSP with C-CSP for patients with diminutive and small colorectal polyps.

METHODS

An electronic literature search was conducted to retrieve articles comparing resection outcomes between SI-CSP and C-CSP in diminutive and small colorectal polyps (registration number INPLASY2023100096). Our primary outcomes of interest were the complete resection rate (CRR), complications (namely immediate bleeding, delayed bleeding and perforation) and polypectomy time. Mean differences with 95% confidence intervals (CI) were employed for continuous variables, while odds ratios (OR) with 95% CI were calculated for categorical variables. Data was analyzed using a random effects model and the I2 test was utilized to assess heterogeneity.

RESULTS

Eight studies involving 1470 patients with 2223 polyps were included in our analysis. The CRR was not significantly higher in the SI-CSP group, with an OR of 95% CI 0.50 (0.22, 1.15). The incidences of immediate bleeding (OR 95% CI 0.60 [0.26-1.40]) and delayed bleeding (OR 95% CI 0.88 [0.32-2.42]) did not differ significantly between the two groups. On average, the mean polypectomy time was 64.75 seconds shorter in the C-CSP group (95% CI, - 102.96 to - 26.53). Notably, no perforation events were reported in the included studies.

CONCLUSIONS

The use of SI-CSP was not superior to C-CSP in managing diminutive and small colorectal polyps and the procedure required significantly more time.

Approaches and considerations in the endoscopic treatment of T1 colorectal cancer

The detection of early colorectal cancer (CRC) is increasing through the implementation of screening programs. This increased detection enhances the likelihood of minimally invasive surgery and significantly lowers the risk of recurrence, thereby improving patient survival and reducing mortality rates. T1 CRC, the earliest stage, is treated endoscopically in cases with a low risk of lymph node metastasis (LNM). The advantages of endoscopic treatment compared with surgery include minimal invasiveness and limited tissue disruption, which reduce morbidity and mortality, preserve bowel function to avoid colectomy, accelerate recovery, and improve cost-effectiveness. However, T1 CRC has a risk of LNM. Thus, selection of the appropriate treatment between endoscopic treatment and surgery, while avoiding overtreatment, is challenging considering the potential for complete resection, LNM, and recurrence risk.

Risk factors for lymph node metastasis in T2 colorectal cancer: a systematic review and meta-analysis

BACKGROUND

Lymph node metastasis (LNM) occurs in 20-25% of patients with T2 colorectal cancer (CRC). Identification of risk factors for LNM in T2 CRC may help identify patients who are at low risk and thereby potential candidates for endoscopic full-thickness resection. We examined risk factors for LNM in T2 CRC with the goal of establishing further criteria of the indications for endoscopic resection.

METHODS

MEDLINE, CENTRAL, and EMBASE were systematically searched from inception to November 2023. Studies that investigated the association between the presence of LNM and the clinical and pathological factors of T2 CRC were included. Odds ratios (ORs) and 95% confidence intervals (CIs) were calculated. Certainty of evidence (CoE) was assessed using the GRADE approach.

RESULTS

Fourteen studies (8349 patients) were included. Overall, the proportion of LNM was 22%. The meta-analysis revealed that the presence of lymphovascular invasion (OR, 5.5; 95% CI 3.7-8.3; high CoE), high-grade tumor budding (OR, 2.4; 95% CI 1.5-3.7; moderate CoE), poor differentiation (OR, 2.2; 95% CI 1.8-2.7; moderate CoE), and female sex (OR, 1.3; 95% CI 1.1-1.7; high CoE) were associated with LNM in T2 CRC. Lymphatic invasion (OR, 5.0; 95% CI 3.3-7.6) was a stronger predictor of LNM than vascular invasion (OR, 2.4; 95% CI 2.1-2.8).

CONCLUSIONS

Lymphovascular invasion, high-grade tumor budding, poor differentiation, and female sex were risk factors for LNM in T2 CRC. Endoscopic resection of T2 CRC in patients with very low risk for LNM may become an alternative to conventional surgical resection.

TRIAL REGISTRATION

PROSPERO, CRD42022316545.

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.

The role of endoscopic ultrasonography for diagnosis of residual rectal neuroendocrine tumor

BACKGROUND

Endoscopic ultrasonography (EUS) is useful for assessing the depth and regional lymph node involvement in rectal neuroendocrine tumors (NETs). However, evidence regarding the effectiveness of EUS in identifying residual lesions in patients with incompletely resected NET is limited. We aimed to evaluate the efficacy of EUS in identifying residual rectal NETs and the clinical outcomes of salvage endoscopic treatment.

METHODS

We retrospectively reviewed the records of patients who were transferred to Chosun University Hospital and received salvage treatment for incompletely resected rectal NETs between January 2012 and October 2021.

RESULTS

This study included 68 incompletely resected rectal NET, of which 59 were margin-positive and 9 were margin-indeterminate. EUS detection (odds ratio (OR), 8.44; 95% confidence interval (CI), 1.18-41.35) and visual detection (OR, 7.00; 95% CI, 1.50-47.48) were associated with residual lesion in patients with incompletely resected NET. EUS detection of residual lesions showed a sensitivity of 94%, specificity of 71%, positive predictive value of 88%, negative predictive value of 83%, and accuracy of 87%. All patients underwent salvage treatment with band-ligation endoscopic mucosal resection (58.8%) and endoscopic submucosal dissection (41.2%). Residual NETs were diagnosed in 47 of 68 patients (69.1%), and no recurrence was noted during the follow-up period of 51.8 ± 22.9 months.

CONCLUSIONS

EUS is a more sensitive method than visual detection for evaluating residual rectal NETs. Salvage endoscopic treatment for incompletely resected NETs is safe and effective.

Effect of an online educational module incorporating real-time feedback on accuracy of polyp sizing in trainees: a randomized controlled trial

BACKGROUND

Although polyp size dictates surveillance intervals, endoscopists often estimate polyp size inaccurately. We hypothesized that an intervention providing didactic instruction and real-time feedback could significantly improve polyp size classification.

METHODS

We conducted a multicenter randomized controlled trial to evaluate the impact of different components of an online educational module on polyp sizing. Participants were randomized to control (no video, no feedback), video only, feedback only, or video + feedback. The primary outcome was accuracy of polyp size classification into clinically relevant categories (diminutive [1-5mm], small [6-9mm], large [≥10mm]). Secondary outcomes included accuracy of exact polyp size (inmm), learning curves, and directionality of inaccuracy (over- vs. underestimation).

RESULTS

36 trainees from five training programs provided 1360 polyp size assessments. The feedback only (80.1%, P=0.01) and video + feedback (78.9%, P=0.02) groups had higher accuracy of polyp size classification compared with controls (71.6%). There was no significant difference in accuracy between the video only group (74.4%) and controls (P=0.42). Groups receiving feedback had higher accuracy of exact polyp size (inmm) and higher peak learning curves. Polyps were more likely to be overestimated than underestimated, and 29.3% of size inaccuracies impacted recommended surveillance intervals.

CONCLUSIONS

Our online educational module significantly improved polyp size classification. Real-time feedback appeared to be a critical component in improving accuracy. This scalable and no-cost educational module could significantly decrease under- and overutilization of colonoscopy, improving patient outcomes while increasing colonoscopy access.

Enhanced multi-class pathology lesion detection in gastric neoplasms using deep learning-based approach and validation

This study developed a new convolutional neural network model to detect and classify gastric lesions as malignant, premalignant, and benign. We used 10,181 white-light endoscopy images from 2606 patients in an 8:1:1 ratio. Lesions were categorized as early gastric cancer (EGC), advanced gastric cancer (AGC), gastric dysplasia, benign gastric ulcer (BGU), benign polyp, and benign erosion. We assessed the lesion detection and classification model using six-class, cancer versus non-cancer, and neoplasm versus non-neoplasm categories, as well as T-stage estimation in cancer lesions (T1, T2-T4). The lesion detection rate was 95.22% (219/230 patients) on a per-patient basis: 100% for EGC, 97.22% for AGC, 96.49% for dysplasia, 75.00% for BGU, 97.22% for benign polyps, and 80.49% for benign erosion. The six-class category exhibited an accuracy of 73.43%, sensitivity of 80.90%, specificity of 83.32%, positive predictive value (PPV) of 73.68%, and negative predictive value (NPV) of 88.53%. The sensitivity and NPV were 78.62% and 88.57% for the cancer versus non-cancer category, and 83.26% and 89.80% for the neoplasm versus non-neoplasm category, respectively. The T stage estimation model achieved an accuracy of 85.17%, sensitivity of 88.68%, specificity of 79.81%, PPV of 87.04%, and NPV of 82.18%. The novel CNN-based model remarkably detected and classified malignant, premalignant, and benign gastric lesions and accurately estimated gastric cancer T-stages.

A simplified algorithm to evaluate the risk of submucosal invasive cancer in large (≥20 mm) nonpedunculated colonic polyps

BACKGROUND

Recognition of submucosal invasive cancer (SMIC) in large (≥20 mm) nonpedunculated colonic polyps (LNPCPs) informs selection of the optimal resection strategy. LNPCP location, morphology, and size influence the risk of SMIC; however, currently no meaningful application of this information has simplified the process to make it accessible and broadly applicable. We developed a decision-making algorithm to simplify the identification of LNPCP subtypes with increased risk of potential SMIC.

METHODS

Patients referred for LNPCP resection from September 2008 to November 2022 were enrolled. LNPCPs with SMIC were identified from endoscopic resection specimens, lesion biopsies, or surgical outcomes. Decision tree analysis of lesion characteristics identified in multivariable analysis was used to create a hierarchical classification of SMIC prevalence.

RESULTS

2451 LNPCPs were analyzed: 1289 (52.6%) were flat, 1043 (42.6%) nodular, and 118 (4.8%) depressed. SMIC was confirmed in 273 of the LNPCPs (11.1%). It was associated with depressed and nodular vs. flat morphology (odds ratios [ORs] 35.7 [95%CI 22.6-56.5] and 3.5 [95%CI 2.6-4.9], respectively; P<0.001); rectosigmoid vs. proximal location (OR 3.2 [95%CI 2.5-4.1]; P<0.001); nongranular vs. granular appearance (OR 2.4 [95%CI 1.9-3.1]; P<0.001); and size (OR 1.12 per 10-mm increase [95%CI 1.05-1.19]; P<0.001). Decision tree analysis targeting SMIC identified eight terminal nodes: SMIC prevalence was 62% in depressed LNPCPs, 19% in nodular rectosigmoid LNPCPs, and 20% in nodular proximal colon nongranular LNPCPs.

CONCLUSIONS

This decision-making algorithm simplifies identification of LNPCPs with an increased risk of potential SMIC. When combined with surface optical evaluation, it facilitates accurate lesion characterization and resection choices.

A new clinical model for predicting lymph node metastasis in T1 colorectal cancer

PURPOSE

Lymph node metastasis (LNM) is a crucial factor that determines the prognosis of T1 colorectal cancer (CRC) patients. We aimed to develop a practical prediction model for LNM in T1 CRC.

METHODS

We conducted a retrospective analysis of data from 825 patients with T1 CRC who underwent radical resection at a single center in China. All enrolled patients were randomly divided into a training set and a validation set at a ratio of 7:3 using R software. Risk factors for LNM were identified through multivariate logistic regression analyses. Subsequently, a prediction model was developed using the selected variables.

RESULTS

The lymph node metastasis (LNM) rate was 10.1% in the training cohort and 9.3% in the validation cohort. In the training set, risk factors for LNM in T1 CRC were identified, including depressed endoscopic gross appearance, sex, submucosal invasion combined with tumor grade (DSI-TG), lymphovascular invasion (LVI), and tumor budding. LVI emerged as the most potent predictor for LNM. The prediction model based on these factors exhibited good discrimination ability in the validation sets (AUC: 79.3%). Compared to current guidelines, the model could potentially reduce over-surgery by 48.9%. Interestingly, we observed that sex had a differential impact on LNM between early-onset and late-onset CRC patients.

CONCLUSIONS

We developed a clinical prediction model for LNM in T1 CRC using five factors that are easily accessible in clinical practice. The model has better predictive performance and practicality than the current guidelines and can assist clinicians in making treatment decisions for T1 CRC patients.

A novel low-power pure-cut hot snare polypectomy for 10-14 mm colorectal adenomas: An ex vivo and a clinical prospective feasibility study (SHARP trial)

BACKGROUND AND AIM

Hot snare polypectomy using blend or coagulation current is widely used; however, it causes deeper tissue heat injury, leading to adverse events. We hypothesized that hot polypectomy using low-power pure cut current (PureCut, effect 1 10 W) could reduce deeper tissue heat injury. We conducted animal experiments to evaluate the deeper tissue heat injury and conducted a prospective clinical study to examine its cutting ability.

METHODS

In a porcine rectum, hot polypectomy using Blend current (EndoCut, effect 3 40 W) and low-power pure cut current was performed. The deepest part of heat destruction and thickness of the non-burned submucosal layer were evaluated histologically. Based on the results, we performed low-power pure cut current hot polypectomy for 10-14 mm adenoma. The primary endpoint was complete resection defined as one-piece resection with negative for adenoma in quadrant biopsies from the defect margin.

RESULTS

In experiments, all low-power pure-cut resections were limited within the submucosal layer whereas blend current resections coagulated the muscular layer in 13% (3/23). The remaining submucosal layer was thicker in low-power pure cut current than in blend current resections. In the clinical study, low-power pure-cut hot polypectomy removed all 100 enrolled polyps. For 98 pathologically neoplastic polyps, complete resection was achieved in 84 (85.7%, 95% confidence interval, 77-92%). The lower limit of the 95% confidence interval was not more than 15% below the pre-defined threshold of 86.6%. No severe adverse events occurred.

CONCLUSIONS

A novel low-power pure-cut hot polypectomy may be feasible for adenoma measuring 10-14 mm. (UMIN000037678).

Cold Snare Polypectomy in Small (<10 mm) Pedunculated Colorectal Polyps: A Systematic Review and Meta-analysis

INTRODUCTION

Endoscopic removal techniques for colorectal polyps include cold snare polypectomy (CSP) and hot snare polypectomy (HSP). Although HSP is recommended for pedunculated polyps (PPs) larger than 10 mm, data regarding use of CSP for PPs <10 mm continues to emerge. We aimed to investigate outcomes of these techniques in small (<10 mm) pedunculated colorectal polyps.

METHODS

Multiple databases were searched till June 2022 to identify studies involving the removal of small PPs with CSP and HSP. Random effects model was used to calculate outcomes and 95% CI. Primary outcome was the pooled rate of successful en-bloc resection. Secondary outcomes were immediate and delayed bleeding with CSP and HSP as well as prophylactic and post resection clip placement.

RESULTS

Six studies including 1025 patients (1111 polyps with a mean size 4 to 8.5 mm) were analyzed. 116 and 995 polyps were removed with HSP and CSP, respectively. The overall pooled rate of successful en-bloc resection with CSP was 99.7% (CI 99.1-99.9; I2 0%). Pooled immediate and delayed bleeding after CSP was 49.8% (CI 46.8-52.91; I2 98%) and 0% (CI 0.00-0.00; I2 0%), respectively. Delayed bleeding was higher with HSP, relative risk 0.05 (CI 0.01-0.43; I2 0%), P =0.006, whereas immediate bleeding was higher with CSP, relative risk 7.89 (CI 4.36-14.29; I2 0%), P <0.00001. Pooled rates of prophylactic clip placement and post-procedure clip placement (to control immediate bleeding) were 55.3% and 47.2%, respectively. Finally, right colon polyp location significantly correlated with frequency of immediate bleeding.

CONCLUSION

Our analysis shows that CSP is safe and effective for resection of small PPs.

Cold Snare Polypectomy With or Without Submucosal Injection for Endoscopic Resection of Colorectal Polyps: A Meta-Analysis of Randomized Controlled Trials

BACKGROUND AND AIMS

The impact of submucosal injection during cold snare polypectomy (CSP) remains uncertain. We conducted an evidence-based comparison of conventional CSP (C-CSP) and CSP with submucosal injection (SI-CSP) for colorectal polyp resection.

METHODS

PubMed, Embase, and the Cochrane Library databases were searched for randomized controlled trials (RCTs) comparing C-CSP with SI-CSP. Major outcomes included the rates of complete resection, en bloc resection, polyp retrieval, and adverse events, as well as the duration of polypectomy. Data were analyzed by using a random-effects model.

RESULTS

A total of seven RCTs were included. Complete resection rates for all polyps (RR 0.98; 95% CI 0.93-1.03), polyps ≤ 10 mm (RR 0.99; 95% CI 0.96-1.02) and polyps > 10 mm (RR 0.92; 95% CI 0.69-1.12) were not substantially different between C-CSP and SI-CSP groups. En bloc resection rate (RR 0.93; 95% CI 0.79-1.09) and polyp retrieval rate (RR 1.00; 95% CI 0.99-1.01) were also not significantly different between the two groups. The SI-CSP group required a prolonged polypectomy time than the C-CSP group (SMD - 0.89; 95% CI -1.29 to -0.49). Adverse events were rare in both groups.

CONCLUSIONS

SI-CSP is not an optimal substitute for CSP in the resection of colorectal polyps, particularly diminutive and small polyps.

Audit of hemostatic clip use after colorectal polyp resection in an academic endoscopy unit

Background and study aims Prophylactic closure of endoscopic resection defects reduces delayed hemorrhage after resection of non-pedunculated colorectal lesions ≥ 20 mm that are located proximal to the splenic flexure and removed by electrocautery. The risk of delayed hemorrhage after cold (without electrocautery) resection is much lower, and prophylactic clip closure after cold resection is generally unnecessary. The aim of this study was to audit clip use after colorectal polyp resection in routine outpatient colonoscopies at two outpatient centers within an academic medical center. Patients referred for resection of known lesions were excluded. Patients and methods Retrospective chart analysis was performed as part of a quality review of physician adherence to screening and post-polypectomy surveillance intervals. Results Among 3784 total lesions resected cold by 29 physicians, clips were placed after cold resection on 41.7% of 12 lesions ≥ 20 mm, 19.3% of 207 lesions 10 to 19 mm in size, and 2.8% of 3565 lesions 1 to 9 mm in size. Three physicians placed clips after cold resection of lesions 1 to 9 mm in 18.8%, 25.5%, and 45.0% of cases. These physicians accounted for 8.1% of 1- to 9-mm resections, but 69.7% of clips placed in this size range. Electrocautery was used for 3.1% of all resections. Clip placement overall after cold resection (3.9%) was much lower than after resection with electrocautery (71.1%), but 62.4% of all clips placed were after cold resection. Conclusions Audits of clip use in an endoscopy practice can reveal surprising findings, including high and variable rates of unnecessary use after cold resection. Audit can potentially reduce unnecessary costs, carbon emissions, and plastic waste.

HOT VERSUS COLD SNARE FOR COLORECTAL POLYPECTOMIES SIZED UP TO 10MM: A SYSTEMATIC REVIEW AND META-ANALYSIS OF RANDOMIZED CONTROLLED TRIALS

BACKGROUND

Colorectal cancer is the third most common cancer, and prevention relies on screening programs with resection complete resection of neoplastic lesions.

OBJECTIVE

We aimed to evaluate the best snare polypectomy technique for colorectal lesions up to 10 mm, focusing on complete resection rate, and adverse events.

METHODS

A comprehensive search using electronic databases was conducted to identify randomized controlled trials comparing hot versus cold snare resection for polyps sized up to 10 mm, and following PRISMA guidelines, a meta-analysis was performed. Outcomes included complete resection rate, en bloc resection rate, polypectomy, procedure times, immediate, delayed bleeding, and perforation.

RESULTS

Nineteen RCTs involving 8720 patients and 17588 polyps were included. Hot snare polypectomy showed a higher complete resection rate (RD, 0.02; 95%CI [+0.00,0.04]; P=0.03; I 2=63%), but also a higher rate of delayed bleeding (RD 0.00; 95%CI [0.00, 0.01]; P=0.01; I 2=0%), and severe delayed bleeding (RD 0.00; 95%CI [0.00, 0.00]; P=0.04; I 2=0%). Cold Snare was associated with shorter polypectomy time (MD -46.89 seconds; 95%CI [-62.99, -30.79]; P<0.00001; I 2=90%) and shorter total colonoscopy time (MD -7.17 minutes; 95%CI [-9.10, -5.25]; P<0.00001; I 2=41%). No significant differences were observed in en bloc resection rate or immediate bleeding.

CONCLUSION

Hot snare polypectomy presents a slightly higher complete resection rate, but, as it is associated with a longer procedure time and a higher rate of delayed bleeding compared to Cold Snare, it cannot be recommended as the gold standard approach. Individual analysis and personal experience should be considered when selecting the best approach.

Recurrence rate after piecemeal endoscopic mucosal resection of <20 mm non-pedunculated colorectal lesions: should we worry about the risk?

INTRODUCTION

There is scarce data focused on recurrence neoplasia rate (RR) after piecemeal endoscopic mucosal resection (pEMR) of 10-19 mm non-pedunculated colorectal lesions (NPL). We aimed to analyze the RR after pEMR of 10-19 mm NPL, identify risk factors for its development and compare it with RR after pEMR of ≥ 20 mm NPL.

METHODS

Retrospective cohort-study including all ≥10 mm NPL resected by pEMR in our center between 2018-2022 with an early repeat colonoscopy (ERC). RR was defined as recurrence neoplasia identified in the ERC EMR scar with virtual chromoendoscopy or histological confirmation.

RESULTS

A total of 444 NPL were assessed, 124 (27.9%) with 10-19 mm. In the ERC, performed a median of 6 months after pEMR, RR was significantly lower for 10-19 mm NPL compared to ≥ 20 mm NPL (13/124 vs 68/320, p = 0.005). In subgroup analysis, RR after pEMR of 15-19 mm NPL was significantly higher compared to 10-14 mm NPL (13/98 vs 0, p = 0.041) but not significantly different compared to ≥ 20 mm NPL (13/98 vs 68/320, p = 0.073). In multivariable analysis, size of NPL (HR 1.501, 95% CI 1.012-2.227, p = 0.044) was the only independent risk factor identified for RR for 10-19 mm NPL.

CONCLUSION

Although the early RR after pEMR of 10-19 mm NPL is significantly lower compared to ≥ 20 mm NPL, it is non-negligible (10.5%) and appears to be the highest among 15-19 mm NPL. The size of the lesion was the only independent risk factor for RR. Our findings should be accounted in the selection of the most appropriate post-polypectomy endoscopic surveillance.

A non-aligned translation with a neoplastic classifier regularization to include vascular NBI patterns in standard colonoscopies

Polyp vascular patterns are key to categorizing colorectal cancer malignancy. These patterns are typically observed in situ from specialized narrow-band images (NBI). Nonetheless, such vascular characterization is lost from standard colonoscopies (the primary attention mechanism). Besides, even for NBI observations, the categorization remains biased for expert observations, reporting errors in classification from 59.5% to 84.2%. This work introduces an end-to-end computational strategy to enhance in situ standard colonoscopy observations, including vascular patterns typically observed from NBI mechanisms. These retrieved synthetic images are achieved by adjusting a deep representation under a non-aligned translation task from optical colonoscopy (OC) to NBI. The introduced scheme includes an architecture to discriminate enhanced neoplastic patterns achieving a remarkable separation into the embedding representation. The proposed approach was validated in a public dataset with a total of 76 sequences, including standard optical sequences and the respective NBI observations. The enhanced optical sequences were automatically classified among adenomas and hyperplastic samples achieving an F1-score of 0.86%. To measure the sensibility capability of the proposed approach, serrated samples were projected to the trained architecture. In this experiment, statistical differences from three classes with a ρ-value <0.05 were reported, following a Mann-Whitney U test. This work showed remarkable polyp discrimination results in enhancing OC sequences regarding typical NBI patterns. This method also learns polyp class distributions under the unpaired criteria (close to real practice), with the capability to separate serrated samples from adenomas and hyperplastic ones.

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.

Accuracy in Polyp Size Measurement Among Surgeons, Gastroenterologists, Trainees, and Experts: A Prospective Video-Based Study

INTRODUCTION

Polyp size determination plays an important role in endoscopic decision making and follow-up determination. However, there is a lack of knowledge of endoscopist accuracy for polyp sizing and efficacy of available tools for size measurement. Our aim was to compare the accuracy of visual assessment, snare, forceps, and virtual scale endoscope (VSE) in estimating polyp size among a diverse group of endoscopists.

METHODS

We conducted a prospective video-based study. One hundred twenty polyps measured and recorded along with all available measurement tools were randomized to visual assessment, snare, forceps, or VSE group. Eleven endoscopists conducted video-based measurement using the randomized measurement tool. Primary outcome was relative accuracy in polyp size measurement compared with caliper measurement immediately postresection.

RESULTS

One thousand three hundred twenty measurements were performed. VSE had statistically significantly higher relative accuracy when compared to forceps (79.3 vs 71.3%; P < 0.0001). Forceps had statistically significantly higher relative accuracy when compared to visual assessment (71.3 vs 63.6%; P = 0.0036). There was no statistically significant difference when comparing visual assessment and snare-based measurements (63.6 vs 62.8%; P = 0.797). Overall, 21.5% of polyps >5 mm were misclassified as ≤5 mm and 17.3% of polyps ≥10 mm were misclassified as <10 mm. VSE had the lowest percentage of polyps >5 mm misclassified as ≤5 mm (2.6%), polyps ≤5 mm misclassified as >5 mm (5.1%), and polyps <10 mm misclassified as ≥10 mm (1.7%).

DISCUSSION

Visual size estimation of polyps is inaccurate independently of training level, sex, and specialty. Size measurement accuracy can be improved using forceps and yields the highest relative accuracy when an adaptive scale technology is used.

Efficacy and Safety of Thermal Ablation after Endoscopic Mucosal Resection: A Systematic Review and Network Meta-Analysis

(1) Background: Large colonic polyps during colonoscopy can be managed by Endoscopic mucosal resection (EMR). To decrease the polyp recurrence rate, thermal ablation methods like argon plasma coagulation (APC) and snare tip soft coagulation (STSC) have been introduced. We performed this network meta-analysis to assess the efficacy and safety of these modalities. (2) Methods: We performed a comprehensive literature review, through 5 January 2024, of databases including Embase, PubMed, SciELO, KCI, Cochrane Central, and Web of Science. Using a random effects model, we conducted a frequentist approach network meta-analysis. The risk ratio (RR) with 95% confidence interval (CI) was calculated. Safety and efficacy endpoints including rates of recurrence, bleeding, perforation, and post polypectomy syndrome were compared. (3) Results: Our search yielded a total of 13 studies with 2686 patients. Compared to placebo, both APC (RR: 0.33 CI: 0.20-0.54, p < 0.01) and STSC (RR: 0.27, CI: 0.21-0.34, p < 0.01) showed decreased recurrence rates. On ranking, STSC showed the lowest recurrence rate, followed by APC and placebo. Regarding individual adverse events, there was no statistically significant difference between either of the thermal ablation methods and placebo. (4) Conclusions: We demonstrated the efficacy and safety of thermal ablation after EMR for decreasing recurrence of adenoma.

Recurrences of advanced sessile and lateral spreading colorectal adenoma after endoscopic mucosal resection (EMR) thermal ablation versus no adjuvant therapy (RESPECT): a protocol of an international randomized controlled trial

BACKGROUND

Nowadays, large benign lateral spreading lesions (LSLs) and sessile polyps in the colorectum are mostly resected by endoscopic mucosal resection (EMR). A major drawback of EMR is the polyp recurrence rate of up to 20%. Snare tip soft coagulation (STSC) is considered an effective technique to reduce recurrence rates. However, clinical trials on STSC have mainly been conducted in expert referral centers. In these studies, polyp recurrence was assessed optically, and additional adjunctive techniques were excluded. In the current trial, we will evaluate the efficacy and safety of STSC in daily practice, by allowing adjunctive techniques during EMR and the use of both optical and histological polyp recurrence to assess recurrences during follow-up.

METHODS

The RESPECT study is a multicenter, parallel-group, international single blinded randomized controlled superiority trial performed in the Netherlands and Germany. A total of 306 patients undergoing piecemeal EMR for LSLs or sessile colorectal polyps sized 20-60 mm will be randomized during the procedure after endoscopic complete polyp resection to the intervention or control group. Post-EMR defects allocated to the intervention group will be treated with thermal ablation with STSC of the entire resection margin. Primary outcome will be polyp recurrence by optical and histological confirmation at the first surveillance colonoscopy after 6 months. Secondary outcomes include technical success and complication rates.

DISCUSSION

The RESPECT study will evaluate if STSC is effective in reducing recurrence rates after piecemeal EMR of large colorectal lesions in daily clinical practice performed by expert and non-expert endoscopists. Moreover, endoscopists will be allowed to use adjunctive techniques to remove remaining adenomatous tissue during the procedure. Finally, adenomatous polyp recurrence during follow-up will be defined by histologic identification.

TRIAL REGISTRATION

ClinicalTrials.gov NCT05121805. Registered on 16 November 2021. Start recruitment: 17 March 2022. Planned completion of recruitment: 31 April 2025.

Engineering tumor-colonizing E. coli Nissle 1917 for detection and treatment of colorectal neoplasia

Bioengineered probiotics enable new opportunities to improve colorectal cancer (CRC) screening, prevention and treatment. Here, first, we demonstrate selective colonization of colorectal adenomas after oral delivery of probiotic E. coli Nissle 1917 (EcN) to a genetically-engineered murine model of CRC predisposition and orthotopic models of CRC. We next undertake an interventional, double-blind, dual-centre, prospective clinical trial, in which CRC patients take either placebo or EcN for two weeks prior to resection of neoplastic and adjacent normal colorectal tissue (ACTRN12619000210178). We detect enrichment of EcN in tumor samples over normal tissue from probiotic-treated patients (primary outcome of the trial). Next, we develop early CRC intervention strategies. To detect lesions, we engineer EcN to produce a small molecule, salicylate. Oral delivery of this strain results in increased levels of salicylate in the urine of adenoma-bearing mice, in comparison to healthy controls. To assess therapeutic potential, we engineer EcN to locally release a cytokine, GM-CSF, and blocking nanobodies against PD-L1 and CTLA-4 at the neoplastic site, and demonstrate that oral delivery of this strain reduces adenoma burden by ~50%. Together, these results support the use of EcN as an orally-deliverable platform to detect disease and treat CRC through the production of screening and therapeutic molecules.

Through-the-scope clip retention rates and performance in a porcine model

Background and study aims Limited comparative data exist to guide optimal through-the-scope (TTS) clip selection. The aim of this study was to compare the efficacy, retention, and safety of three industry-leading TTS clips on tissue that mimics common clinical scenarios. Methods A survival study involving six domestic pigs was undertaken. Three commonly used clip models were selected: Assurance (STERIS, Mentor, Ohio, United States), Resolution (Boston Scientific, Boston, Massachusetts, United States), and SureClip (Micro-Tech, Ann Arbor, Michigan, United States). To mimic clinical practice, the following scenarios were assessed: (1) normal mucosa; (2) cold snare resection; and (3) hot mucosal resection simulating fibrotic ulcers. Deployment of clips was randomized to target sites. Repeat endoscopy was performed 2 weeks following placement. Endoscopists rated the ease of use of clip placement on a Likert scale of 1 to 5. Results Fifty-four clips (18 Assurance, 18 Resolution, and 18 SureClip) were placed in six pigs. Mucosal healing was noted at all sites on follow up. Overall retention was nine of 18 (50.0%) SureClip, 10 of 18 (55.6%) Assurance, and 13 of 18 (72.2%) Resolution ( P =0.369). There was no difference in clip retention on normal and cold snare resection sites; however, clip retention was significantly higher for Resolution clips on fibrotic ulcers (50.0% versus 0% for Assurance and 0% SureClip, P =0.03). No adverse events were reported. Ease of use was equivalent across all models. Conclusions All clips were equivalent in efficacy and safety with successful clip deployment and mucosal healing. Overall retention rate was low for fibrotic tissue, with an improved retention rate observed with Resolution clips.

Use of artificial intelligence in the management of T1 colorectal cancer: a new tool in the arsenal or is deep learning out of its depth?

The field of artificial intelligence is rapidly evolving, and there has been an interest in its use to predict the risk of lymph node metastasis in T1 colorectal cancer. Accurately predicting lymph node invasion may result in fewer patients undergoing unnecessary surgeries; conversely, inadequate assessments will result in suboptimal oncological outcomes. This narrative review aims to summarize the current literature on deep learning for predicting the probability of lymph node metastasis in T1 colorectal cancer, highlighting areas of potential application and barriers that may limit its generalizability and clinical utility.

Low delayed bleeding and high complete closure rate of mucosal defects with the novel through-the-scope dual-action tissue clip after endoscopic resection of large nonpedunculated colorectal lesions (with video)

BACKGROUND AND AIMS

Complete closure after endoscopic resection of large nonpedunculated colorectal lesions (LNPCLs) can reduce delayed bleeding but is challenging with conventional through-the-scope (TTS) clips alone. The novel dual-action tissue (DAT) clip has clip arms that open and close independently of each other, facilitating tissue approximation. We aimed to evaluate the rate of complete closure and delayed bleeding with the DAT clip after endoscopic resection of LNPCLs.

METHODS

This was a multicenter prospective cohort study of all patients who underwent defect closure with the DAT clip after EMR or endoscopic submucosal dissection (ESD) of LNPCLs ≥20 mm from July 2022 to May 2023. Delayed bleeding was defined as a bleeding event requiring hospitalization, blood transfusion, or any intervention within 30 days after the procedure. Complete closure was defined as apposition of mucosal defect margins without visible submucosal areas <3 mm along the closure line.

RESULTS

One hundred seven patients (median age, 64 years; 42.5% women) underwent EMR (n = 63) or ESD (n = 44) of LNPCLs (median size, 40 mm; 74.8% right-sided colon) followed by defect closure. Complete closure was achieved in 96.3% (n = 103) with a mean of 1.4 ± .6 DAT clips and 2.9 ± 1.8 TTS clips. Delayed bleeding occurred in 1 patient (.9%) without requiring additional interventions.

CONCLUSIONS

The use of the DAT clip in conjunction with TTS clips achieved high complete defect closure after endoscopic resection of large LNPCLs and was associated with a .9% delayed bleeding rate. Future comparative trials and formal cost-analyses are needed to validate these findings. (Clinical trial registration number: NCT05852457.).

Safety and efficacy of physician-administered balanced-sedation for the endoscopic mucosal resection of large non-pedunculated colorectal polyps

Background and study aims Because of concerns about peri-procedural adverse events (AEs), guidelines recommend anesthetist-managed sedation (AMS) for long and complex endoscopic procedures. The safety and efficacy of physician-administered balanced sedation (PA-BS) for endoscopic mucosal resection (EMR) of large non-pedunculated colorectal polyps (LNPCPs) ≥20 mm is unknown. Patients and methods We compared PA-BS with AMS in a retrospective study of prospectively collected data from consecutive patients referred for management of LNPCPs (NCT01368289; NCT02000141). A per-patient propensity analysis was performed following a 1:2 nearest-neighbor (Greedy-type) match, based on age, gender, Charlson comorbidity index, and lesion size. The primary outcome was any peri-procedural AE, which included hypotension, hypertension, tachycardia, bradycardia, hypoxia, and new arrhythmia. Secondary outcomes were unplanned admissions, 28-day re-presentation, technical success, and recurrence. Results Between January 2016 and June 2020, 700 patients underwent EMR for LNPCPs, of whom 638 received PA-BS. Among them, the median age was 70 years (interquartile range [IQR] 62-76 years), size 35 mm (IQR 25-45 mm), and duration 35 minutes (IQR 25-60 minutes). Peri-procedural AEs occurred in 149 (23.4%), most commonly bradycardia (116; 18.2%). Only five (0.8%) required an unplanned sedation-related admission due to AEs (2 hypotension, 1 arrhythmia, 1 bradycardia, 1 hypoxia), with a median inpatient stay of 1 day (IQR 1-3 days). After propensity-score matching, there were no differences between PA-BS and AMS in peri-procedural AEs, unplanned admissions, 28-day re-presentation rates, technical success or recurrence. Conclusions Physician-administered balanced sedation for the EMR of LNPCPs is safe. Peri-procedural AEs are infrequent, transient, rarely require admission (<1%), and are experienced in similar frequencies to those receiving anesthetist-managed sedation.

Effectiveness and safety of thin vs. thick cold snare polypectomy of small colorectal polyps: Systematic review and meta-analysis

Background and study aims Cold-snare polypectomy (CSP) is considered the standard of care for resection of colorectal polyps ≤10 mm. Data on the efficacy of CSP performed with thin-wire snares compared0 with thick-wire snares are conflicting. We performed a meta-analysis comparing complete resection (CR) and adverse event rates of CSP using thin-wire and thick-wire snares. Patients and methods Comparative studies of adult patients with ≧1 colorectal polyp(s) ≦10 mm who underwent CSP with thin-wire or thick-wire snares were included. We collected data on study, patient, polyp, and snare characteristics. The primary outcome was CR rate. Secondary outcomes were polyp retrieval rate, intraprocedural bleeding, delayed post-polypectomy bleeding, deep mural injury or perforation, patient discomfort, total sedation, and procedure time. We used random-effects models to calculate risk ratios for outcomes. We performed risk of bias assessments, rated the certainty of evidence, and assessed publication bias for all studies. Results We included four randomized controlled trials (RCTs) and two observational studies including 1316 patients with 1679 polyps (826 thin-wire CSPs and 853 thick-wire CSPs). There was no significant difference between thin-wire CSP (92.1%) and thick-wire CSP (87.7%) for RCTs (risk ratio [RR] 1.05, 95% confidence interval [CI] 0.94-1.16) or observational studies (78.1% versus 79.6%, RR 1.03, 95% CI 0.99-1.08). There were no significant differences in polyp retrieval rate or intraprocedural bleeding. There were no cases of delayed bleeding or perforation. Conclusions We found no differences in CR rates for CSP between thin-wire and thick-wire snares. CSP, regardless of snare type, is safe and effective for resection of small colorectal polyps.

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.

Colon polyps: updates in classification and management

PURPOSE OF REVIEW

Colon polyps are potential precursors to colorectal cancer (CRC), which remains one of the most common causes of cancer-associated death. The proper identification and management of these colorectal polyps is an important quality measure for colonoscopy outcomes. Here, we review colon polyp epidemiology, their natural history, and updates in endoscopic classification and management.

RECENT FINDINGS

Colon polyps that form from not only the adenoma, but also the serrated polyp pathway have significant risk for future progression to CRC. Therefore, correct identification and management of sessile serrated lesions can improve the quality of screening colonoscopy. Malignant polyp recognition continues to be heavily reliant on well established endoscopic classification systems and plays an important role in intraprocedural management decisions. Hot snare remains the gold standard for pedunculated polyp resection. Nonpedunculated noninvasive lesions can be effectively removed by large forceps if diminutive, but cold snare is preferred for colon polyps 3-20 mm in diameter. Larger lesions at least 20 mm require endoscopic mucosal resection. Polyps with the endoscopic appearance of submucosal invasion require surgical referral or advanced endoscopic resection in select cases. Advances in artificial intelligence may revolutionize endoscopic polyp classification and improve both patient and cost-related outcomes of colonoscopy.

SUMMARY

Clinicians should be aware of the most recent updates in colon polyp classification and management to provide the best care to their patients initiating screening colonoscopy.

Cold snare polypectomy compared to cold forceps polypectomy for endoscopic resection of guideline defined diminutive polyps: A systematic review and meta-analysis of randomized trials

BACKGROUND

International guidelines recommend cold snare polypectomy (CSP) for polyps  < 10 mm in size. However, recent randomized clinical trials (RCTs) showed conflicting results for the use of cold forceps polypectomy (CFP) vs. CSP for the resection of diminutive colorectal polyps (DCPs) (≤ 5 mm), especially for polyps  ≤ 3 mm. Herein we compared CFP with CSP for patients with DCPs in this meta-analysis of RCTs.

METHODS

We systematically searched the Cochrane Library, PubMed and EMBASE databases from inception to November 24, 2022, (Registration number INPLASY2022110135). The primary endpoint was DCP complete resection rate. The secondary endpoints were mean polypectomy time, polyp retrieval rate and complications.

RESULTS

Seven RCTs involving 1023 DCPs were included. The complete resection rate (91.6% vs. 94.7%) for CFP was not significantly lower for polyps ≤ 5 mm (relative risk [RR] = 1.03; 95% confidence interval [CI]: 0.98-1.07). Sub-group analysis showed that the complete resection rate (88.7% vs. 92.4%) for CFP was not significantly lower for DCPs > 3 mm (RR = 1.04; 95% CI: 0.97-1.12). Another sub-group analysis showed that the complete resection rate (97.0% vs. 96.3%) was similar for polyps ≤ 3 mm for CFP vs. CSP (RR = 1.00; 95% CI: 0.98-1.03). The mean polypectomy time was not different between CFP and CSP (95% CI: -11.86-10.18). The polyp retrieval rate (100% vs. 96.9%) was not significantly higher for CFP (RR = 1.02; 95% CI: 0.98-1.07). There were no reported complications in the included studies. The overall study quality was moderate except for the removal of polyps ≤ 5 mm (low-quality evidence).

CONCLUSION

CFP was comparable to CSP for the resection of polyps ≤ 3 mm; however, caution should be taken for DCPs > 3 mm because of the low complete resection rate (< 90%).

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.

Frequency of endoscopic photodocumentation of large colorectal polyps

BACKGROUND AND AIMS

Colonoscopy quality affects colorectal cancer (CRC) incidence and mortality. The U.S. Multi-Society Task Force on Colorectal Cancer strongly recommends photodocumentation (PD) of lesions ≥10 mm in size (ie, large polyps [LPs]) pre-resection and suggests PD postresection to enhance the quality of colonoscopy. No studies have assessed the frequency of LP PD. We evaluated the frequency of and factors associated with PD of LPs.

METHODS

Reports from endoscopists performing ≥50 colonoscopies with LP resection between 2016 and 2021 were reviewed. The frequency of LP PD pre-resection and post-resection and factors associated with PD were collected. A composite score of 2 quality metrics (PD of completeness of examination and bowel preparation quality) was created. Endoscopists were divided into 2 tiers based on the frequency of the score on all included examinations: Tier 1, ≥95% of examinations; and Tier 2, <95% of examinations. Univariate and multivariate analyses were used to assess factors associated with PD.

RESULTS

A total of 1322 colonoscopies, 1693 LPs, and 25 endoscopists were included in this study. PD of LPs occurred in 1392 (82%) pre-resection and in 878 (52%) post-resection. Factors associated with pre-resection PD include endoscopist subspecialty (colorectal surgery vs gastroenterology: odds ratio [OR], .12; 95% confidence interval [CI], .04-.42); >1 LP on examination (2 vs 1 LP: OR, .41 [95% CI, .27-.61]; and ≥3 vs 1 LP: OR, .41 [95% CI, .24-.70]), and longer withdrawal time (OR, 1.02; 95% CI, 1.01-1.04).

CONCLUSIONS

We provide the first data on PD of LP pre-resection and post-resection, which can inform future benchmarking in this area. The implications of PD on metachronous advanced neoplasia need to be studied.

Impact of Submucosal Saline Injection During Cold Snare Polypectomy for Colorectal Polyps Sized 3-9 mm: A Multicenter Randomized Controlled Trial

INTRODUCTION

The role of submucosal injection during cold snare polypectomy (CSP) remains uncertain. In this study, we investigated the impact of submucosal saline injection during CSP for colorectal polyps sized 3-9 mm.

METHODS

This was a multicenter randomized controlled trial conducted in 6 Chinese centers between July and September 2020 (ChiCTR2000034423). Patients with nonpedunculated colorectal polyps sized 3-9 mm were randomized in a 1:1 ratio to either CSP with submucosal injection (SI-CSP) or conventional CSP (C-CSP). The primary outcome was the incomplete resection rate (IRR). Secondary outcomes included procedure time, intraprocedural bleeding, delayed bleeding, and perforation.

RESULTS

One hundred fifty patients with 234 polyps in the SI-CSP group and 150 patients with 216 polyps in the C-CSP group were included in the analysis. The IRR was not decreased in the SI-CSP group compared with that in the C-CSP group (1.7% vs 1.4%, P = 1.000). The median procedure time in the SI-CSP group was significantly longer than that in the C-CSP group (108 seconds vs 48 seconds, P < 0.001). The incidences of intraprocedural bleeding and delayed bleeding were not significantly different between the 2 groups ( P = 0.531 and P = 0.250, respectively). There was no perforation in either group.

DISCUSSION

Submucosal saline injection during CSP for colorectal polyps sized 3-9 mm did not decrease the IRR or reduce adverse events but prolonged the procedure time.

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).

Varied Trainee Competence in Cold Snare Polypectomy: Results of the COMPLETE Randomized Controlled Trial

INTRODUCTION

Cold snare polypectomy (CSP) is strongly recommended as the optimal technique for the complete removal of small polyps. Though significant variability in polypectomy technique and quality has been established, the learning curve and impact of targeted training on CSP are unknown. Video feedback has shown promise as an effective pedagogy to improve performance among surgical trainees. We aimed to compare CSP performance between trainees who received video-based feedback and those who received conventional apprentice-based concurrent feedback. We hypothesized that video-based feedback would accelerate competence.

METHODS

We conducted a single-blinded, randomized controlled trial on competence for CSP of polyps <1 cm, comparing video-based feedback with conventional feedback. We randomly assigned deidentified consecutively recorded CSP videos to blinded raters to assess using the CSP Assessment Tool. We shared cumulative sum learning curves every 25 CSP with each trainee. The video feedback trainees also received biweekly individualized terminal feedback. Control trainees received conventional feedback during colonoscopy. The primary outcome was CSP competence. We also assessed competence across domains and change over polypectomy volume.

RESULTS

We enrolled and randomized 22 trainees, 12 to video-based feedback and 10 to conventional feedback, and evaluated 2,339 CSP. The learning curve was long; 2 trainees (16.7%) in the video feedback achieved competence, after a mean of 135 polyps, and no one in the control ( P = 0.481) achieved competence. Overall and in all steps of CSP, a higher percentage of the video feedback group met competence, increasing 3% every 20 CSP ( P = 0.0004).

DISCUSSION

Video feedback aided trainees to competence in CSP. However, the learning curve was long. Our findings strongly suggest that current training methods are not sufficient to support trainees to competency by the completion of their fellowship programs. The impact of new training methods, such as simulation-based mastery learning, should be assessed to determine whether such methods can result in achievement of competence at a faster rate; ClinicalTrials.gov : NCT03115008.

Fibroblast Activation Protein-α (FAP) Identifies Stromal Invasion in Colorectal Neoplasia

The increasing detection of colorectal adenomas and early adenocarcinomas (ADCs) in the context of nationwide screening programs has led to a significant increase in the incidence of inconclusive diagnoses in which histopathologic analysis of endoscopic biopsies does not allow pathologists to provide a reliable diagnosis of stromal invasion. The objective of this study was to analyze the discriminative capacity of the immunohistochemical expression of fibroblast activation protein-α (FAP) in distinguishing colorectal adenomas with low-grade dysplasia (LGD) and high-grade dysplasia (HGD) from invasive intestinal-type ADCs. The study analyzed the first endoscopic biopsies from a series of patients classified as inconclusive or conclusive for stromal invasion based on the pathologic report. In total, 30 ADCs, 52 HGDs, and 15 LGDs were included in the study. FAP expression was detected in 23/30 ADCs and was negative in all adenomas with either LGD or HGD features (100% specificity and 76.7% sensitivity, area under the curve=0.883, CI=0.79-0.98). Considering these findings, we conclude that FAP is a potentially useful tool for helping pathologists identify invasive lesions in colorectal endoscopic biopsies, avoiding unnecessary biopsy repetitions.

Intestinal topical lidocaine spray improves the efficacy and safety of endoscopic sigmoid polypectomy

BACKGROUND AND AIMS

Endoscopic polypectomy can prevent colorectal cancer. Adequate surgical field visualization is crucial to complete resection. To prevent visual field loss caused by intestinal peristalsis, we investigated the efficacy and safety of topical lidocaine spraying during the endoscopic sigmoid polypectomy (ESP).

METHODS

Retrospective analysis was performed on 100 ESP patients admitted from July 2021 to October 2021, among which 50 patients received lidocaine (case group) and other 50 patients received normal saline (control group). Lidocaine or saline was sprayed on the colonic mucosa within 5 cm above and below the polyps before polypectomy. The en-bloc resection rate (EBRR) and complete resection rate (CRR) were primarily evaluated. Secondary outcomes included EBRR for polyps located in the 5-11 o'clock position, sigmoid colon peristalsis frequency, degree of exposure to the surgical field, operative times, and adverse events.

RESULTS

There were no significant differences in the basic demographic characteristics between the two groups. EBRR and CRR in the case group were 72.9% and 95.8%, and in the control group were 53.3% and 91.1%, respectively. The EBRR of sigmoid polyps located at the 5-11 o'clock positions was significantly higher in the case group (82.8%) than in the control group (56.7%) (P = 0.03). Sigmoid colonic peristalsis was significantly inhibited after lidocaine spraying (P < 0.01). There was no statistical difference in the operative times and adverse event rates between the two groups.

CONCLUSION

Topical spraying lidocaine around polyps can safely and effectively reduce intestinal peristalsis, thus improving the EBRR of sigmoid polypectomy.

Deep learning-based clinical decision support system for gastric neoplasms in real-time endoscopy: development and validation study

BACKGROUND : Deep learning models have previously been established to predict the histopathology and invasion depth of gastric lesions using endoscopic images. This study aimed to establish and validate a deep learning-based clinical decision support system (CDSS) for the automated detection and classification (diagnosis and invasion depth prediction) of gastric neoplasms in real-time endoscopy. METHODS : The same 5017 endoscopic images that were employed to establish previous models were used for the training data. The primary outcomes were: (i) the lesion detection rate for the detection model, and (ii) the lesion classification accuracy for the classification model. For performance validation of the lesion detection model, 2524 real-time procedures were tested in a randomized pilot study. Consecutive patients were allocated either to CDSS-assisted or conventional screening endoscopy. The lesion detection rate was compared between the groups. For performance validation of the lesion classification model, a prospective multicenter external test was conducted using 3976 novel images from five institutions. RESULTS : The lesion detection rate was 95.6 % (internal test). On performance validation, CDSS-assisted endoscopy showed a higher lesion detection rate than conventional screening endoscopy, although statistically not significant (2.0 % vs. 1.3 %; P = 0.21) (randomized study). The lesion classification rate was 89.7 % in the four-class classification (advanced gastric cancer, early gastric cancer, dysplasia, and non-neoplastic) and 89.2 % in the invasion depth prediction (mucosa confined or submucosa invaded; internal test). On performance validation, the CDSS reached 81.5 % accuracy in the four-class classification and 86.4 % accuracy in the binary classification (prospective multicenter external test). CONCLUSIONS : The CDSS demonstrated its potential for real-life clinical application and high performance in terms of lesion detection and classification of detected lesions in the stomach.

Cold snare versus cold forceps polypectomy for endoscopic resection of diminutive polyps: meta-analysis of randomized controlled trials

BACKGROUND AND AIMS

The practices for resection of diminutive colon polyps vary among endoscopists, and U.S. Multi-Society Task force guidelines recommend use of cold snare polypectomy (CSP) for this purpose. In this meta-analysis, we compared CSP and cold forceps polypectomy (CFP) for resection of diminutive polyps.

METHODS

Several databases were reviewed to identify randomized controlled trials that compared CSP and CFP for resection of diminutive polyps. The study outcomes of interest were complete resection of all diminutive polyps, complete resection of polyps ≤3 mm in size, failure of tissue retrieval, and polypectomy time. For categorical variables, pooled odds ratios (ORs) with 95% confidence intervals (CIs) were calculated; for continuous variables, mean differences (MDs) with 95% CIs were calculated. Data were analyzed by using a random-effects model, and heterogeneity was assessed by using the I2 statistic.

RESULTS

We included 9 studies with 1037 patients. Rate of complete resection of all diminutive polyps was significantly higher in the CSP group (OR, 1.68; 95% CI, 1.09-2.58). Subgroup analysis, including jumbo or large-capacity forceps, found no significant difference in complete resection between groups (OR, 1.43; 95% CI, .80-2.56). We found no significant between-groups in the rates of complete resection of polyps ≤3 mm in size (OR, .83; 95% CI, .30-2.31). Rate of failure of tissue retrieval was significantly higher in the CSP group (OR, 10.13; 95% CI, 2.29-44.74). No significant between-group difference was noted in polypectomy time.

CONCLUSIONS

CFP using large-capacity or jumbo biopsy forceps is noninferior to CSP for complete resection of diminutive polyps.

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

INTRODUCTION

Cold polypectomy has the advantages of simple operation, less time-consuming and fewer complications. Guidelines have recommended cold snare polypectomy (CSP) to resect small polyps sized ≤5 mm and sessile polyps sized 6-9 mm. However, evidence is scarce regarding cold resection for non-pedunculated polyps sized ≥10 mm. Cold snare endoscopic mucosal resection (CS-EMR) combining CSP and submucosal injection was designed to improve the complete resection rate and reduce adverse events. We hypothesise that CS-EMR is non-inferior to conventional hot snare endoscopic mucosal resection (HS-EMR) in the resection of 10-19 mm non-pedunculated colorectal polyps.

METHODS AND ANALYSIS

This study is a prospective, randomised, open-label, non-inferiority, single-centre trial. Outpatients scheduled to undergo a colonoscopy and present eligible polyps will be randomised to receive either CS-EMR or HS-EMR. The primary endpoint is the complete resection. Considering that HS-EMR of 10-19 mm colorectal polyps will yield a complete resection rate of at least 92% and a non-inferiority margin of -10%, a total of 232 polyps will be included (one-sided α, 2.5%; β, 20%). The analyses are intended to evaluate first non-inferiority (lower limit 95% CI greater than -10% for group difference) and then superiority (lower limit 95% CI>0%) if non-inferiority is achieved. Secondary endpoints include en-bloc resection, the occurrence of adverse events, the use of endoscopic clips, resection time and cost.

ETHICS AND DISSEMINATION

The study has been approved by the institutional review board of the Peking Union Medical College Hospital (No. K2203). All participants in the trial will provide written informed consent. The results of this trial will be published in an open-access way.

TRIAL REGISTRATION NUMBER

NCT05545787.

A Cluster Randomized Trial of a Family Health History Platform to Identify and Manage Patients at Increased Risk for Colorectal Cancer

BACKGROUND

Obtaining comprehensive family health history (FHH) to inform colorectal cancer (CRC) risk management in primary care settings is challenging.

OBJECTIVE

To examine the effectiveness of a patient-facing FHH platform to identify and manage patients at increased CRC risk.

DESIGN

Two-site, two-arm, cluster-randomized, implementation-effectiveness trial with primary care providers (PCPs) randomized to immediate intervention versus wait-list control.

PARTICIPANTS

PCPs treating patients at least one half-day per week; patients aged 40-64 with no medical conditions that increased CRC risk.

INTERVENTIONS

Immediate-arm patients entered their FHH into a web-based platform that provided risk assessment and guideline-driven decision support; wait-list control patients did so 12 months later.

MAIN MEASURES

McNemar's test examined differences between the platform and electronic medical record (EMR) in rates of increased risk documentation. General estimating equations using logistic regression models compared arms in risk-concordant provider actions and patient screening test completion. Referral for genetic consultation was analyzed descriptively.

KEY RESULTS

Seventeen PCPs were randomized to each arm. Patients (n = 252 immediate, n = 253 control) averaged 51.4 (SD = 7.2) years, with 83% assigned male at birth, 58% White persons, and 33% Black persons. The percentage of patients identified as increased risk for CRC was greater with the platform (9.9%) versus EMR (5.2%), difference = 4.8% (95% CI: 2.6%, 6.9%), p < .0001. There was no difference in PCP risk-concordant action [odds ratio (OR) = 0.7, 95% CI (0.4, 1.2; p = 0.16)]. Among 177 patients with a risk-concordant screening test ordered, there was no difference in test completion, OR = 0.8 [0.5,1.3]; p = 0.36. Of 50 patients identified by the platform as increased risk, 78.6% immediate and 68.2% control patients received a recommendation for genetic consultation, of which only one in each arm had a referral placed.

CONCLUSIONS

FHH tools could accurately assess and document the clinical needs of patients at increased risk for CRC. Barriers to acting on those recommendations warrant further exploration.

TRIAL REGISTRATION NUMBER

ClinicalTrials.gov NCT02247336 https://clinicaltrials.gov/ct2/show/NCT02247336.

Colorectal cancer detection and treatment with engineered probiotics

Bioengineered probiotics enable new opportunities to improve colorectal cancer (CRC) screening, prevention and treatment strategies. Here, we demonstrate the phenomenon of selective, long-term colonization of colorectal adenomas after oral delivery of probiotic E. coli Nissle 1917 (EcN) to a genetically-engineered murine model of CRC predisposition. We show that, after oral administration, adenomas can be monitored over time by recovering EcN from stool. We also demonstrate specific colonization of EcN to solitary neoplastic lesions in an orthotopic murine model of CRC. We then exploit this neoplasia-homing property of EcN to develop early CRC intervention strategies. To detect lesions, we engineer EcN to produce a small molecule, salicylate, and demonstrate that oral delivery of this strain results in significantly increased levels of salicylate in the urine of adenoma-bearing mice, in comparison to healthy controls. We also assess EcN engineered to locally release immunotherapeutics at the neoplastic site. Oral delivery to mice bearing adenomas, reduced adenoma burden by ∼50%, with notable differences in the spatial distribution of T cell populations within diseased and healthy intestinal tissue, suggesting local induction of robust anti-tumor immunity. Together, these results support the use of EcN as an orally-delivered platform to detect disease and treat CRC through its production of screening and therapeutic molecules.

Complete endoscopic removal rate of detected colorectal polyps in a real world out-patient practical setting

OBJECTIVES

Colonoscopy with adenomatous polypectomy reduces the incidence and mortality of colorectal cancer. We introduced a strategy of removing all neoplastic polyps in single-session out-patient colonoscopy using cold polypectomy. We aimed to investigate the achievement of single-session complete removal rate of detected colorectal polyps in clinical practice.

MATERIALS AND METHODS

This retrospective study included colonoscopy-scheduled 40-79-year-old outpatients, with at least one colorectal neoplasm, between January 2015 and December 2016. Exclusion criteria were: colorectal neoplasms 21 mm or larger in size; pre-examination for colorectal surgery or endoscopic submucosal dissection; colonoscopy performed by health check program; ongoing antithrombotic treatment; inflammatory bowel disease; familial adenomatous polyposis. We defined 'clean colon' as the removal of all detected neoplastic polyps in a single-session colonoscopy. We evaluated clean colon rate, factors relating to clean colon failure and complications.

RESULTS

We evaluated 2527 patients (mean age 68 years; 799 women) with 8203 colorectal polyps (7675 adenomas, 423 serrated lesions, 105 Tis and T1 cancers). In 1-4 mm polyps, cold snare polypectomy (CSP; 51.8%) and cold forceps polypectomy (CFP; 45.8%) were applied. Clean colon rates were 95.1% per patient and 97.1% per lesion. The significant factors denoting clean colon failure were inadequate bowel preparation, ≥5 lesions, and the most advanced estimated histology of adenocarcinoma, on multivariate analyses. Post-polypectomy bleeding requiring endoscopic hemostasis occurred in five patients (0.2%) who had undergone endoscopic mucosal resection (EMR) or hot snare polypectomy (HSP). Perforation occurred in one patient (0.04%) with EMR.

CONCLUSIONS

The clean colon rates were satisfactory in single-session out-patient colonoscopy using cold polypectomy.