Complementation by argon plasma coagulation after endoscopic piecemeal resection of large colorectal adenomas

Analyzing methods for reducing recurrence rates after EMR of large nonpedunculated colorectal polyps: an indirect pairwise comparison

BACKGROUND AND AIMS

Despite advances in EMR techniques, a high polyp recurrence rate remains a challenge. Due to the scarcity of direct comparisons, we performed an indirect comparison of conventional EMR (EMR alone), underwater EMR (U-EMR), and EMR + adjuvant thermal ablation of polypectomy margins to assess polyp recurrence rates.

METHODS

Electronic databases were searched from inception to January 12, 2023, for studies reporting polyp recurrence rates after EMR for large nonpedunculated polyps (>15 mm) with or without adjuvant techniques (snare tip soft coagulation [STSC]/argon plasma coagulation [APC]). An indirect comparison was performed by using the frequentist method. The p-score was calculated to identify preferred intervention. Publication bias was assessed by using a comparison-adjusted funnel plot.

RESULTS

A total of 9 full articles were identified. On direct comparisons, EMR + STSC had 82% reduced odds (odds ratio, .18; 95% confidence interval, .13-.26; P < .001), whereas U-EMR alone had 77% reduced odds (odds ratio, .23; 95% confidence interval, .08-.67; P = .007) of polyp recurrence compared with EMR alone. On indirect comparison, all interventions had significantly lower odds of polyp recurrence compared with EMR alone. The p-score ranking showed that EMR + STSC seems a potential first method in reducing the odds of polyp recurrence, followed by U-EMR, EMR + APC, and EMR alone.

CONCLUSIONS

EMR + STSC seems to provide favorable odds for reducing polyp recurrence postresection for large nonpedunculated polyps. Standardization of methods to detect residual polyp and prevent polyp recurrence at the time of EMR are required.

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.

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

BACKGROUND AND AIMS

Increasing lesion size is a risk factor for recurrence after piecemeal EMR (pEMR). Snare-tip soft coagulation (STSC) treatment of the normal-appearing margin after pEMR of lesions ≥ 20 mm has been shown to reduce recurrence rates by 75% to 80%. We sought to evaluate the impact of STSC on giant (≥ 40 mm) lateral spreading lesions treated by pEMR. We describe the relative risk and absolute risks of recurrence with and without STSC margin treatment after EMR of ≥ 40-mm lesions.

METHODS

We performed a retrospective evaluation of a prospectively collected database on large lesions describing lesion size, location, and methods of resection. We excluded lesions < 40 mm in maximum dimension, those that did not undergo follow-up care at our center, and those in which argon plasma coagulation was used for either ablative treatment of residual polyp or margin treatment. Propensity score analysis was used to account for potential differences between patients treated with and without STSC.

RESULTS

There were 68 lesions ≥ 40 mm removed by pEMR without STSC treatment and 133 removed and treated with STSC. There were no differences between groups in demographics, polyp size, location, histologic features, and mean follow-up time. The recurrence rate in the no-treatment group was 35% versus 9% with STSC (P < .00001 by direct comparison and P = .008 by using the propensity score analysis).

CONCLUSION

STSC treatment after pEMR of large lateral spreading lesions in the colorectum reduced recurrences by 75%. However, the absolute recurrence rate of 9% remained clinically significant in the STSC-treated group. Short-term follow-up care after STSC of lesions ≥ 40 mm is still warranted, and additional study of technical factors that eliminate recurrence after pEMR of giant lateral spreading lesions is warranted.

Cold snare polypectomy vs. hot snare polypectomy vs. argon plasma coagulation for small (5-9mm) left-sided colorectal polyps: a prospective randomized trial

OBJECTIVE

To compare recurrence rates among three endoscopic treatment modalities for 5-9 mm left-sided colorectal polyps.

METHODS

Consecutive adults referred for elective colonoscopy (1/2015-1/2018) with at least one polyp of eligible size (5-9 mm) located distally to the splenic flexure were randomly assigned (1:1:1) to one of three treatment modalities: (1) cold snare polypectomy (CSP), (2) hot snare polypectomy (HSP) and (3) argon plasma coagulation (APC) ablation (50-60 W, flow: 2 l/min). The polyp site was marked with an endoscopic tattoo, and a follow-up colonoscopy with scar biopsies was performed >6 months after the index procedure. Outcomes were polyp recurrence rate and occurrence of complications.

RESULTS

One hundred nineteen patients were enrolled, of whom 112 (62.5% males, mean age 61.1 ± 9.9 years) with 121 polyps (CSP, 39; HSP, 45; APC, 37) returned for follow-up colonoscopy. Mean polyp size was 6.7 ± 0.91 mm, 58% were located in the sigmoid, 33% in the rectum and 8% in the descending colon. The majority of polyps resected by CSP or HSP were neoplastic (tubular adenomas: 25.9%, tubulovillous adenomas: 11.1% and sessile serrate adenomas/polyps: 17.5%). No cases of delayed bleeding or perforation occurred. Scar biopsies at follow-up colonoscopy (performed after a mean interval of 13.4 ± 3.8 months) revealed 7 (5.8%) cases of polyp recurrence, showing no significant difference among the three treatment groups [CSP, 3/39 (7.7%); HSP, 1/45 (2.2%); APC, 2/37 (5.4%); P = 0.51).

CONCLUSIONS

CSP, HSP and APC-ablation are effective and well-tolerated treatment modalities for 5-9 mm left-sided colorectal polyps. The present randomized study did not detect any difference in polyp recurrence rate among the three endoscopic techniques.

Endoscopic techniques to reduce recurrence rates after colorectal EMR: systematic review and meta-analysis

Background

Colorectal endoscopic mucosal resection (EMR) is an effective, safe, and minimally invasive treatment for large lateral spreading and sessile polyps. The reported high recurrence rate of approximately 20% is however one of the major drawbacks. Several endoscopic interventions have been suggested to reduce recurrence rates. We conducted a systematic review and meta-analysis to assess the efficacy of endoscopic interventions targeting the EMR margin to reduce recurrence rates.

Methods

We searched in PubMed and Ovid for studies comparing recurrence rates after interventions targeting the EMR margin with standard EMR. The primary outcome was the recurrence rate at the first surveillance colonoscopy (SC1) assessed histologically or macroscopically. For the meta-analysis, risk ratios (RRs) were calculated and pooled using a random effects model. The secondary outcome was post-procedural complication rates.

Results

Six studies with a total of 1335 lesions were included in the meta-analysis. The techniques performed in the intervention group targeting the resection margin were argon plasma coagulation, snare tip soft coagulation, extended EMR, and precutting EMR. The interventions reduced the adenoma recurrence rate with more than 50%, resulting in a pooled RR of 0.37 (95% CI 0.18, 0.76) comparing the intervention group with the control groups. Overall post-procedural complication rates did not increase significantly in the intervention arm (RR 1.30; 95% CI 0.65, 2.58).

Conclusion

Interventions targeting the EMR margin decrease recurrence rates and may not result in more complications.

Supplementary Information

The online version contains supplementary material available at 10.1007/s00464-021-08574-z.