Impact of margin thermal treatment after EMR of giant (≥40 mm) colorectal lateral spreading lesions

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

BACKGROUND

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

OBJECTIVE

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

DESIGN

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

RESULTS

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

CONCLUSION

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

TRIAL REGISTRATION NUMBER

Australian Colonic Endoscopic Resection cohort (NCT01368289; NCT02000141).

Safety of first surveillance colonoscopy at 12 months after piecemeal EMR of large nonpedunculated colorectal lesions

BACKGROUND AND AIMS

After piecemeal EMR (pEMR) of nonpedunculated colorectal lesions ≥20 mm, guidelines recommend first endoscopic surveillance at 6 months. However, initial surveillance at 12 months may be adequate for selected low-risk lesions and could save the cost, risk, and inconvenience of 1 surveillance examination.

METHODS

This study retrospectively examined a prospectively collected database of all colorectal lesions referred to our center for endoscopic resection between August 2019 and April 2023. We report recurrence rates of patients with colorectal lesions ≥20 mm removed by pEMR who were assigned to 6-month first surveillance or to 12-month first surveillance (or assigned to a 6-month surveillance visit but did not return until after 10 months).

RESULTS

There were 561 nonpedunculated lesions ≥20 mm that underwent first follow-up, including 490 lesions in 443 patients assigned to 6-month surveillance and 71 lesions in 65 patients assigned to 12-month surveillance. Lesions assigned to 12-month surveillance were smaller (mean size, 25.9 ± 6.1 mm vs 37.0 ± 17.4 mm), more likely serrated (63.4% vs 9.6%), and more often removed by cold pEMR (74.6% vs 20.4%). Twenty-nine lesions in 24 patients assigned to 6-month surveillance presented after 10 months, and their recurrence data were included in the group assigned to 12-month surveillance. Overall recurrence rates at 6 months and 12 months were 10.0% (46 of 461) and 10.0% (10 of 100), respectively. Mean recurrence sizes at 6 and 12 months were 10.9 ± 6.2 mm and 5.0 ± 3.1 mm, respectively. One patient in the 6-month surveillance group had cancer at the pEMR site, but no other recurrences at 6 or 12 months had either cancer or high-grade dysplasia.

CONCLUSIONS

Twelve-month surveillance seems acceptable for selected colorectal lesions ≥20 mm removed by pEMR. A randomized trial comparing initial 6-month versus 12-month surveillance is warranted for selected lesions.

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

BACKGROUND & AIMS

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

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.

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

BACKGROUND

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

OBJECTIVE

To compare ESD and EMR for large colonic adenomas.

DESIGN

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

SETTING

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

PARTICIPANTS

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

INTERVENTION

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

MEASUREMENTS

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

RESULTS

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

LIMITATION

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

CONCLUSION

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

PRIMARY FUNDING SOURCE

French Ministry of Health.

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

INTRODUCTION

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

METHODS

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

RESULTS

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

CONCLUSION

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