A systematic description of the post-EMR defect to identify risk factors for clinically significant post-EMR bleeding in the colon

Incomplete mucosal layer excision during EMR: a potential source of recurrent adenoma (with video)

BACKGROUND AND AIMS

Residual or recurrent adenoma (RRA) detected during surveillance is the major limitation of EMR. The pathogenesis of RRA is unknown, although thermal ablation of the post-endoscopic resection defect (PED) margin reduces RRA. We aimed to identify a feature within the PED that could be associated with RRA.

METHODS

Between January 2017 and July 2020, detailed prospective procedural data on all EMR procedures performed at a single center were retrospectively analyzed. At the completion of EMR, the PED was systematically examined for features of incomplete mucosal layer excision (IME). This was defined as a demarcated area within the PED bordered by a white electrocautery ring and containing endoscopically identifiable features suggesting incomplete resection of the mucosa including lacy capillaries and/or visible fibers of the muscularis mucosae. Areas of IME were reinjected and re-excised by snare and submitted separately for blinded specialist GI pathologist review.

RESULTS

EMR was performed for 508 large nonpedunculated colorectal polyps (LNPCPs) (median size, 35 mm). In 10 PEDs (2.0%), an area of IME was identified and excised. Histopathologic examination of areas of suspected IME demonstrated muscularis mucosae in 9 of 10 (90%), residual lamina propria in 9 of 10 (90.0%), and residual adenoma in 5 of 10 (50.0%). No RRA was detected during follow-up after re-excision of IME.

CONCLUSIONS

We report the novel finding of IME within the PED after EMR of LNPCPs. IME may contain microscopic residual adenoma and therefore is a risk for RRA during follow-up. After completion of EMR, the PED should be carefully evaluated. If IME is found, it should be excised. (Clinical trial registration number: NCT01368289 and NCT02000141.).

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.

Clip-assisted endoloop ligation of the mucosal defect after resection of colorectal polyps decreased postprocedural delayed bleeding

BACKGROUND

Postprocedural delayed bleeding (PDB) remains the most common major complication of colorectal polypectomy. Incomplete clip closure of mucosal defect and unclosed injured blood vessels in gaps between clips may be the risk factors for PDB.

OBJECTIVES

To observe whether completely no-gap closure of mucosal defect after polypectomy can reduce PDB occurrence.

DESIGN

Single-center, retrospective case-control study.

METHODS

In this study based on historical comparisons of patients in 2 time periods, only the patients with polyps sized between 6 and 15 mm were included. A new clip-assisted endoloop ligation (CAEL, treatment group) method was used between January 2019 and December 2020, and a traditional simple clip closure (SCC, control) was used Between January 2017 and December 2018 to prevent PDB after polypectomy. The rate of PDB of two groups and risk factors for PDB were evaluated.

RESULTS

Totally 4560 patients were included in the study; 2418 patients belong to CAEL group, and 2142 patients belong to SCC group. The overall rate of PDB was significantly lower in CAEL group compared to SCC group (0.6% versus 1.5%, p < 0.00). On multivariate logistic analysis, CAEL was a significant independent preventive factor for PDB (odds ratio (OR), 0.092; 95% confidence interval (CI), 0.029-0.3335; p = 0.000). Polyps located at rectum (colon versus rectum) represented a significant independent risk factor for PDB (OR, 11.888; 95% CI, 3.343-42.269; p = 0.001).

CONCLUSION

Completely no-gap closure of mucosal defect after polypectomy further reduced the rate of PDB for polyps sized between 6 and 15 mm. CAEL may be a significant independent preventive factor for PDB. Polyps located at the rectum may be a significant independent risk factor for PDB.

Evolving management of colorectal polyps

Advances in endoscopic technology have led to increased success in colorectal cancer (CRC) screening and polyp management, with reduction of CRC incidence and mortality. Despite these advances, CRC is still one of the leading causes of cancer deaths, and half of all CRC develops from lesions that were missed during colonoscopy while one-fifth of CRC arise from prior incomplete resection. Techniques to improve polyp detection are needed, along with optimization of complete resection of any abnormal lesions that are found. This article will review the currently available endoscopic resection techniques and will discuss where they fit in the management of polyps of different sizes and types, such as pedunculated versus nonpedunculated, and those with or without suspected invasion.

Hybrid resection of large colorectal adenomas combining EMR and FTRD

BACKGROUND

The introduction of the full-thickness resection device (FTRD) allowed resection of difficult adenomas in the duodenum and colorectum with non-lifting. The main limitation of this endoscopic technique is the lesion size. We describe a hybrid approach combining endoscopic mucosal resection (EMR) and FTRD in a cohort of 17 patients to reduce tumor size and enable full-thickness resection.

METHODS

Retrospective analysis from data of 17 patients who underwent hybrid EMR-FTRD for large adenomas in the colorectum at our institution. Technical success, histological confirmation of margin-free resection and adverse advents were studied.

RESULTS

16 of 17 (94.1%) lesions could be resected macroscopically complete with confirmed full-thickness resection. Histological work-up of the full-thickness specimens showed free lateral margins in 13 patients (76.4%), unclear margins in two patients (11.8%) and positive margins in two patients (11.8%). There were no immediate perforation or major bleeding, however one patient showed a stenosis after resection in the follow-up endoscopy. Follow-up endoscopy was available in 12 patients. In two of 12 patients a recurrent adenoma was detected.

CONCLUSIONS

Hybrid EMR-EFTR in the colorectum seems to be a safe and effective technique for large non-lifting lesions with positive lifting signs in the margins. Further prospective evaluation of efficacy, safety and long-term outcome of this hybrid technique is necessary.

Factors involved in endoscopists' choice for prophylactic clipping after colorectal endoscopic mucosal resection: a discrete choice experiment

Background: Delayed bleeding (DB) occurs in ∼10% after colorectal EMR. Prophylactic clipping (PC) was reported to significantly decrease DB-rate in proximal lesions ≥2 cm.Objective: Our aim was to determine which predefined variables contribute to using PC in clinical practice.Methods: We performed an international discrete choice experiment (DCE) among ∼500 endoscopists. Relevant variables for PC use were selected by EMR experts: previous DB, anticoagulants, polyp size, morphology, location, intraprocedural bleeding and visible vessel(s). Respondents answered case scenarios with various variable combinations, each time choosing only one scenario for PC, or the 'none' option. Part-worth utilities and importance weights were calculated using HB regression. Subsequently, a predictive model was created to calculate the likelihood of endoscopists choosing PC in any given case.Results: The survey was completed by 190 EMR endoscopists from 17 countries. In total, 8% would never use PC, whereas 30.9% never chose the 'none' option. All variables except polyp type were significant in decision-making for PC (p < .01). The most important factor was anticoagulant use, accounting for 22.5% in decision-making. Polyps <2 cm were considered eligible for PC by 14% in the presence of high-weighing factors such as anticoagulant use. No significant differences were found between high and low-to-moderately experienced endoscopists.Conclusions: PC after EMR is often considered useful by endoscopists, usually based on risk factors for DB. Anticoagulant use was the most important factor in decision-making for PC, independent of endoscopist experience. Although not considered cost-effective, one in seven endoscopists chose PC for adenomas <2 cm.

Impact of en bloc resection on long-term outcomes after endoscopic mucosal resection: a matched cohort study

BACKGROUND AND AIMS

Residual or recurrent adenoma (RRA) is the major limitation of piecemeal EMR (p-EMR) for large colonic laterally spreading lesions (LSLs) ≥20 mm. En bloc EMR (e-EMR) has been shown to achieve low rates of RRA but specific procedural and long-term outcomes are unknown. Our aim was to compare long-term outcomes of size-matched LSLs stratified by whether they were resected e-EMR or p-EMR.

METHODS

Data from a prospective tertiary referral multicenter cohort of large LSLs referred for EMR over a 10-year period were analyzed. Outcomes were compared between sized-matched LSLs (20-25 mm) resected by p-EMR or e-EMR.

RESULTS

Five hundred seventy LSLs met the inclusion criteria of which 259 (45.4%) were resected by e-EMR. The risk of major deep mural injury (DMI) was significantly higher in the e-EMR group (3.5% vs 1.0%, P = .05), whereas rates of other intraprocedural adverse events did not differ significantly. Five of 9 (56%) LSLs, with endoscopic features of submucosal invasion (SMI), resected by e-EMR were saved from surgery. RRA at first surveillance was lower in the e-EMR group (2.0% vs 5.7%, P = .04), but this difference was negated at subsequent surveillance. Rates of surgical referral were not significantly different between the groups at either surveillance interval.

CONCLUSION

When comparing e-EMR against p-EMR for lesions ≤25 mm in size of similar morphology in a large prospective multicenter cohort, e-EMR offered no additional advantage for predicted-benign LSLs. However, it was associated with an increased risk of major DMI. Thus, en bloc resection techniques should be reserved for lesions suspicious for invasive disease. (Clinical trial registration number: NCT01368289.).

Periprocedural adverse events after endoscopic resection of T1 colorectal carcinomas

BACKGROUND AND AIMS

In contrast to the adverse event (AE) risk of endoscopic resection (ER) of adenomas, the intra- and postprocedural AE risks of ER of T1 colorectal cancer (CRC) are scarcely reported in the literature. It is unclear whether ER of early CRCs, which grow into the submucosal layer and sometimes show incomplete lifting, is associated with an increased AE risk. We aimed to identify the AE rate after ER of T1 CRCs and to identify the risk factors associated with these AEs.

METHODS

Medical records of patients with T1 CRCs diagnosed between 2000 and 2014 in 15 hospitals in the Netherlands were reviewed. Patients who underwent primary ER were selected. The primary outcome was the occurrence of endoscopy-related AEs. The secondary outcome was the identification of risk factors. Multivariate logistic regression was performed.

RESULTS

Endoscopic AEs occurred in 59 of 1069 (5.5%) patients, among which 37.3% were classified as mild, 59.3% as moderate, and 3.4% as severe. AEs were postprocedural bleeding (n = 40, 3.7%), perforation (n = 13, 1.2%), and postpolypectomy electrocoagulation syndrome (n = 6, 0.6%). No fatal AEs were observed. Independent predictors for AEs were age >70 years (odds ratio, 2.11; 95% confidence interval, 1.12-3.96) and tumor size >20 mm (odds ratio, 2.22; 95% confidence interval, 1.05-4.69).

CONCLUSIONS

In this large multicenter retrospective cohort study, AE rates of ER of T1 CRC (5.5%) are comparable with reported AE rates for adenomas. Larger tumor size and age >70 years are independent predictors for AEs. This study suggests that endoscopic treatment of T1 CRCs is not associated with an increased periprocedural AE risk.

Intra-procedural and delayed bleeding after resection of large colorectal lesions: The SCALP study

Background and aim

The safety of endoscopic resection of large colorectal lesions (LCLs) (≥20 mm) is clinically relevant. The aim of the present study was to assess the rate of post-resection adverse events (AEs) in a real-life setting.

Patients and methods

In a prospective, multicentre, observational study, data from consecutive resections of LCLs over a 6-month period were collected in 24 centres. Patients were followed up at 15 days from resection for AEs. The primary endpoint was intra-procedural bleeding according to lesion morphology. Secondary endpoints were delayed bleeding and perforation. Patient and polyp characteristics, and polypectomy techniques were analysed with respect to the bleeding events.

Results

In total, 1504 patients (female/male: 633/871, mean age, 66.1) with 1648 LCLs (29.1% pedunculated and 70.9% non-pedunculated lesions) were included. Overall, 168 (11.2%) patients had post-resection bleeding (8.5 and 2.0% immediate and delayed, respectively), while 15 (1.0%) cases of perforation occurred. Independent predictors of immediate bleeding for pedunculated lesions were bleeding prophylaxis (odds ratio (OR) 0.28, 95% confidence interval (CI) 0.13-0.62), simple polypectomy (versus endoscopic mucosal resection, OR 0.38, 95% CI 0.17-0.88) and inpatient setting (OR 2.21, 95% CI 1.07-5.08), while bleeding prophylaxis (OR 0.37, 95% CI 0.30-0.98), academic setting (OR 0.27, 95% CI 0.12-0.54) and size (OR 1.03, 95% CI 1.00-1.05) were predictors for those non-pedunculated. Indication for colonoscopy (screening versus diagnostic (OR 0.33, 95% CI 0.12-0.86)), antithrombotic therapy (OR 3.12, 95% CI 1.54-6.39) and size (OR 2.34, 95% CI 1.12-4.87) independently predicted delayed bleeding.

Conclusions

A low rate of post-resection AEs was observed in a real-life setting, reassuring as to the safety of endoscopic resection of ≥2 cm colorectal lesions. Bleeding prophylaxis reduced the intra-procedural bleeding risk, while antithrombotic therapy increased delayed bleeding.CLINICALTRIAL: (NCT02694120).