Treatment with argon plasma coagulation reduces recurrence after piecemeal resection of large sessile colonic polyps: a randomized trial and recommendations

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.

Long-term adenoma recurrence and development of colorectal cancer following endoscopic mucosal resection in large non-pedunculated colonic polyps ≥4 cm

OBJECTIVES

Data of long-term follow up for large non pedunculated colorectal polyps (LNPCPs) ≥4 cm removed with piecemeal wide field endoscopic mucosal resection (PWF-EMR) are limited. We primarily evaluated the recurrence rates and secondarily the rates of post colonoscopic polypectomy colorectal cancer (PCPCRC) on a long-term basis.

METHODS

We retrospectively reviewed a prospectively-stored electronic database of all patients who underwent PWF-EMR for LNPCPs at the Venizeleion General Hospital, between 2009 and 2020. Eligible patients were those with LNPCPs ≥4 cm, deemed completely removed by endoscopic means and followed-up for a minimum of 36 months with at least two surveillance colonoscopies, the first one (SC1) (4-6) months after the initial PWF-EMR procedure and the second one (SC2) after (12-18) months. In 2023, all cases were checked for PCPCRC development.

RESULTS

Residual/early recurrent tissue was detected in 44 (31 %) cases among the 142 (82 males, 60 females) assessed during SC1. Late recurrent tissue was detected in 9 (6.6 %) cases among the 137 surveyed during SC2. Investigation did not reveal any case of PCPCRC .

CONCLUSIONS

This historical cohort shows that the PWF-EMR for LNPCPs ≥4 cm is a safe and definitive removal method while it is not associated with the appearance of PCPCRC.

Argon Plasma Coagulation as Treatment for Anal Condylomas: A Narrative Review

OBJECTIVES

Anal condylomas are a manifestation of anal human papillomavirus infection and can be associated with precancerous lesions and squamous cell carcinomas. Several methods have been described for treatment, including argon plasma coagulation. A narrative review of the evidence published on this topic was conducted.

METHODS

A search was conducted using PubMed, Scopus, and Web of Science databases.

RESULTS

Five studies reported on anal/perianal condyloma treatment with argon plasma coagulation. In 3 of these studies, there was a comparison with other treatment methods (addition of imiquimod, electrofulguration, and electrocautery, respectively). Argon plasma coagulation settings varied between studies. This type of treatment was effective for ablation. Recurrence rates and follow-up times varied largely between studies. No major complications, such as pain, scarring, sexual dysfunction, or severe bleeding were described.

CONCLUSION

Studies indicate that argon plasma coagulation is an effective and safe therapy for anal and perianal condylomas.

Snare Tip Soft Coagulation vs Argon Plasma Coagulation vs No Margin Treatment After Large Nonpedunculated Colorectal Polyp Resection: a Randomized Trial

BACKGROUND & AIMS

Thermal treatment of the defect margin after endoscopic mucosal resection (EMR) of large nonpedunculated colorectal lesions reduces the recurrence rate. Both snare tip soft coagulation (STSC) and argon plasma coagulation (APC) have been used for thermal margin treatment, but there are few data directly comparing STSC with APC for this indication.

METHODS

We performed a randomized 3-arm trial in 9 US centers comparing STSC with APC with no margin treatment (control) of defects after EMR of colorectal nonpedunculated lesions ≥15 mm. The primary end point was the presence of residual lesion at first follow-up.

RESULTS

There were 384 patients and 414 lesions randomized, and 308 patients (80.2%) with 328 lesions completed ≥1 follow-up. The proportion of lesions with residual polyp at first follow-up was 4.6% with STSC, 9.3% with APC, and 21.4% with control subjects (no margin treatment). The odds of residual polyp at first follow-up were lower for STSC and APC when compared with control subjects (P = .001 and P = .01, respectively). The difference in odds was not significant between STSC and APC. STSC took less time to apply than APC (median, 3.35 vs 4.08 minutes; P = .019). Adverse event rates were low, with no difference between arms.

CONCLUSIONS

In a randomized trial STSC and APC were each superior to no thermal margin treatment after EMR. STSC was faster to apply than APC. Because STSC also results in lower cost and plastic waste than APC (APC requires an additional device), our study supports STSC as the preferred thermal margin treatment after colorectal EMR. (Clinicaltrials.gov, Number NCT03654209.).

Long-term outcomes of endoscopic or surgical resection in T1 colorectal cancer patients: a retrospective cohort study

BACKGROUND

The personalized treatments of T1 colorectal cancer (CRC) remains controversial. We compared the long-term outcomes of T1 CRC patients after endoscopic resection (ER) and surgery, and evaluated the risk factors for the long-term prognosis.

METHODS

T1 CRCs after resection at the Cancer Hospital, Chines Academy of Medical Sciences from June 2011 to November 2021 were reviewed. High-risk factors included positive resection margin, poor differentiation, deep submucosal invasion (DSI ≥ 1000 μm), lymphovascular invasion and intermediate/high tumor budding. Comparative analyses were conducted based on three treatment methods: follow-up after ER (Group A), additional surgery after ER (Group B) and initial surgery (Group C). The primary endpoints included recurrence-free survival (RFS) and overall survival (OS). Cox proportional hazard regression models were constructed to identify risk factors for RFS and OS.

RESULTS

A total of 528 patients were enrolled (173 patients in Group A, 102 patients in Group B, 253 patients in Group C). The 3-year RFS, 5-year RFS, 3-year OS, and 5-year OS rates were 96.7%, 94.7%, 99.1%, and 97.8%, respectively. In the absence of other high-risk factors, RFS (P = 0.321) and OS (P = 0.155) of patients with DSI after ER were not inferior to those after surgery. Multivariate analyses identified sex (HR 0.379; 95% CI 0.160-0.894), Charlson comorbidities index (CCI) (HR 3.330; 95% CI 1.571-7.062), margin (HR 8.212; 95% CI 2.325-29.006), and budding (HR 3.794; 95% CI 1.686-8.541) as independent predictive factors of RFS, and identified CCI (HR 10.266; 95% CI 2.856-36.899) as an independent predictive factor of OS.

CONCLUSION

The long-term outcomes of ER are comparable to those of surgery in T1 CRC patients with DSI when other high-risk factors are negative. Resection margin, tumor budding, sex, and CCI may be the most important long-term prognostic factors for T1 CRC patients.

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.

Does completing advanced endoscopy fellowship improve outcomes after endoscopic mucosal resection?

BACKGROUND

It was reported that about 60% of the physicians in the USA believed that their Gastroenterology fellowship poorly prepared them for large polyp resection. The aim of this study was to compare endoscopic mucosal resection (EMR) efficacy and complication rates between skilled general gastroenterologists who perform high volume of EMR and advanced endoscopists.

METHODS

We identified 140 patients with documented large colonic polyps treated by 4 providers using EMR technique at Carilion Clinic, in Roanoke, Virginia, USA between 01/01/2014-12/31/2017, with follow-up through 10-2018. Information on demographics, clinical and pathological features of high-risk polyps (i.e., size, histology, site, and degree of dysplasia), timing of surveillance endoscopies, tools used during resection, and skills of performing endoscopist's were extracted. The cumulative risks of polyp recurrence after first resection using EMR technique were estimated using Kaplan-Meier curves.

RESULTS

One hundred and forty patients were identified (mean age, 64.1±11.2 years; 47.1% males). Fifty-five polyps (39.3%) were removed by 2 skilled gastroenterologists and 85 (60.7%) were removed by advanced endoscopists. Most of the polyps resected were located in the right colon (63.6%) and roughly half of the polyps were removed in piecemeal fashion. At follow-up endoscopy, the advanced endoscopy group had lower polyp recurrence rates. The median recurrence after polypectomy was significantly different between the groups (0.88 and 1.03 years for skilled gastroenterologists who did not complete and completed EMR hands-on workshops; respectively vs. 3.99 years for the advanced endoscopist who did not complete EMR hands-on workshop, P=0.03).

CONCLUSIONS

There is a need for additional EMR training since polyp recurrence was significantly different between the groups despite high rates of piecemeal resection in the advanced endoscopy groups.

Risk of Residual Neoplasia after a Local-Risk Resection of Colorectal Lesions by Endoscopic Submucosal Dissection: A Multinational Study

Endoscopic submucosal dissection (ESD) in colorectal lesions is demanding, and a significant rate of non-curative procedures is expected. We aimed to assess the rate of residual lesion after a piecemeal ESD resection, or after an en bloc resection but with positive horizontal margins (local-risk resection-LocRR), for colorectal benign neoplasia. A retrospective multicenter analysis of consecutive colorectal ESDs was performed. Patients with LocRR ESDs for the treatment of benign colorectal lesions with at least one follow-up endoscopy were included. A cohort of en bloc resected lesions, with negative margins, was used as the control. A total of 2255 colorectal ESDs were reviewed; 352 of the ESDs were "non-curative". Among them, 209 were LocRR: 133 high-grade dysplasia and 76 low-grade dysplasia. Ten cases were excluded due to missing data. A total of 146 consecutive curative resections were retrieved for comparison. Compared to the "curative group", LocRRs were observed in lengthier procedures, with larger lesions, and in non-granular LSTs. Recurrence was higher in the LocRR group (16/199, 8% vs. 1/146, 0.7%; p = 0.002). However, statistical significance was lost when considering only en bloc resections with positive horizontal margins (p = 0.068). In conclusion, a higher rate of residual lesion was found after a piecemeal ESD resection, but not after an en bloc resection with positive horizontal margins.

Endoscopic management of colorectal polyps

Colorectal polyps are premalignant lesions in the lower gastrointestinal tract. Endoscopic polypectomy is an effective strategy to prevent colorectal cancer morbidity and more invasive procedures. Techniques for the endoscopic resection of polyps keep evolving, and endoscopists are required to perform the most appropriate technique for each polyp. In this review, we outline the evaluation and classification of polyps, update the recommendations for optimal treatment, describe the polypectomy procedures and their strengths/weaknesses, and discuss the promising innovative methods or concepts.

Impact of margin ablation after EMR of large nonpedunculated colonic polyps in routine clinical practice

BACKGROUND AND AIMS

Owing to its simplicity, effectiveness, and safety, EMR is the preferred treatment for the majority of large (≥20 mm) nonpedunculated colonic polyps (LNPCPs); however, residual and recurrent adenomas (RRAs) encountered during surveillance constitute a major limitation. Thermal ablation of the post-EMR mucosal defect margin has been shown to be highly efficacious in reducing RRA in a randomized trial setting, but data on effectiveness in clinical practice are scarce. We aimed to determine the effectiveness of this technique for reducing RRAs in routine clinical practice.

METHODS

We analyzed data collected in 3 hospitals in Israel: Prospective data were available in 2 hospitals where margin thermal ablation with snare-tip soft coagulation (STSC) is routinely performed after EMR of LNPCP (TA-EMR). Only retrospective data were available from the third center, which exclusively did not perform STSC (standard EMR] [S-EMR]), during the study period. Surveillance was performed 4 to 6 months after resection. RRA was assessed endoscopically with high-definition white light and optical chromoendoscopy. The primary endpoint was RRA at first surveillance colonoscopy.

RESULTS

Data from 764 patients with 824 LNPCPs were analyzed. The patient and lesion characteristics were similar between the groups. Four hundred sixty-four LNPCPs were treated by TA-EMR and 360 LNPCPs by S-EMR. RRA at first surveillance colonoscopy was detected in 14 (3.6%) of lesions in the TA-EMR group compared with 96 (31.6%) in the S-EMR group (P < .001; RR = .14; 95% CI, .07-.29). Adverse events were comparable between the 2 groups.

CONCLUSION

TA-EMR leads to a significant reduction in post-EMR recurrence in routine clinical practice.

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.

Post-EMR for colorectal polyps, thermal ablation of defects reduces adenoma recurrence: A meta-analysis

Background and study aims  Adenoma recurrence is one of the key limitations of endoscopic mucosal resection (EMR), which occurs in 15 % to 30 % of cases during first surveillance colonoscopy. The main hypothesis behind adenoma recurrence is leftover micro-adenomas at the margins of post-EMR defects. In this systematic review and meta-analysis, we evaluated the efficacy of snare tip soft coagulation (STSC) at the margins of mucosal defects to reduce adenoma recurrence and bleeding complications. Methods  Electronic databases such as PubMed and the Cochrane library were used for systematic literature search. Studies with polyps only resected by piecemeal EMR and active treatment: with STSC, comparator: non-STSC were included. A random effects model was used to calculate the summary of risk ratio and 95 % confidence intervals. The main outcome of the study was to compare the effect of STSC versus non-STSC with respect to adenoma recurrence at first surveillance colonoscopy after thermal ablation of post-EMR defects. Results  Five studies were included in the systematic review and meta-analysis. The total number patients who completed first surveillance colonoscopy (SC1) in the STSC group was 534 and in the non-STSC group was 514. The pooled adenoma recurrence rate was 6 % (37 of 534 cases) in the STSC arm and 22 % (115 of 514 cases) in the non-STSC arm, (odds ratio [OR] 0.26, 95 % confidence interval [CI], 0.16-0.41, P  = 0.001). The pooled delayed post-EMR bleeding rate 19 % (67 of 343) in the STSC arm and 22 % (78 of 341) in the non-STSC arm (OR 0.82, 95 %CI, 0.57-1.18). Conclusions  Thermal ablation of post-EMR defects significantly reduces adenoma recurrence at first surveillance colonoscopy.

Thermal ablation of mucosal defect margins to prevent local recurrence of large colorectal polyps: a systematic review and meta-analysis

Background and study aims  Endoscopic mucosal resection of large non-pedunculated colorectal polyps is characterized by a high risk of recurrence. Thermal ablation of the mucosal defect margins may reduce recurrence in these lesions, but a systematic overview of the current evidence is lacking. Methods  We searched PubMed, Embase and Cochrane until July 2021, for studies on thermal ablation of mucosal defect margins of large non-pedunculated colorectal polyps. Main goal of this meta-analysis was to identify pooled risk difference of recurrence between thermal ablation vs. no adjuvant treatment. Secondary goal was to identify pooled recurrence rate after snare tip soft coagulation (STSC) and argon plasma coagulation (APC). Results  Ten studies on thermal ablation of mucosal defect margins were included, with three studies on argon plasma coagulation, six studies on snare tip soft coagulation and one study comparing both treatment modalities, representing a total of 316 APC cases and 1598 STSC cases. Overall pooled risk difference of recurrence was -0.17 (95 % confidence interval [CI] -0.22 to -0.12) as compared to no adjuvant treatment. Pooled risk difference was -0.16 (95 % CI -0.19 to -0.14) for STSC and -0.26 (95 % CI -0.80 to 0.28) for APC. Pooled recurrence rate was 4 % (95 % CI 2 % to 8 %) for STSC and 9 % (95 % CI 4 % to 19 %) for APC. Conclusions  Thermal ablation of mucosal defect margins significantly reduces recurrence rate in large non-pedunculated colorectal lesions compared to no adjuvant treatment. While no evidence for superiority exists, STSC may be preferred over APC, because this method is the most evidence-based, and cost-effective modality.

Hybrid argon plasma coagulation-assisted endoscopic mucosal resection for large sessile colon polyps to reduce local recurrence: a prospective pilot study

BACKGROUND

Endoscopic mucosal resection (EMR) of large, sessile colon polyps often results in incomplete resection with subsequent recurrence. The aim of this prospective pilot study was to evaluate the efficacy and safety of a novel technique, hybrid argon plasma coagulation-assisted EMR (hAPC-EMR), to remove large, sessile polyps.

METHODS

40 eligible patients underwent hAPC-EMR for the removal of one or more nonpedunculated colon polyps ≥ 20 mm. Participants were contacted 30 days post-procedure to assess for adverse events and were recommended to return for a surveillance colonoscopy at 6 months to assess for local recurrence.

RESULTS

At the time writing, 32 patients with 35 polyps (median size 27 mm; interquartile range 14.5 mm) resected by hAPC-EMR had undergone the 6-month follow-up colonoscopy. Recurrence rate was 0 % (95 % confidence interval [CI] 0-0) at follow-up. Post-polypectomy bleeding was experienced by three patients (7.5 %; 95 %CI 0.00-0.15), and no patients developed post-polypectomy syndrome.

CONCLUSION

These preliminary results showed 0 % local recurrence rate at 6 months and demonstrated the safety profile of hAPC-EMR. A large, randomized, controlled trial is required to confirm these results.

Histopathological effects of electrosurgical interventions in an in vivo porcine model of colonic endoscopic mucosal resection

OBJECTIVE

Endoscopic mucosal resection (EMR) in the colon has been widely adopted, but there is limited data on the histopathological effects of the differing electrosurgical currents (ESCs) used. We used an in vivo porcine model to compare the tissue effects of ESCs for snare resection and adjuvant margin ablation techniques.

DESIGN

Standardised EMR was performed by a single endoscopist in 12 pigs. Two intersecting 15 mm snare resections were performed. Resections were randomised 1:1 using either a microprocessor-controlled current (MCC) or low-power coagulating current (LPCC). The lateral margins of each defect were treated with either argon plasma coagulation (APC) or snare tip soft coagulation (STSC). Colons were surgically removed at 72 hours. Two specialist pathologists blinded to the intervention assessed the specimens.

RESULTS

88 defects were analysed (median 7 per pig, median defect size 29×17 mm). For snare ESC effects, 156 tissue sections were assessed. LPCC was comparable to MCC for deep involvement of the colon wall. For margin ablation, 172 tissue sections were assessed. APC was comparable to STSC for deep involvement of the colon wall. Islands of preserved mucosa at the coagulated margin were more likely with APC compared with STSC (16% vs 5%, p=0.010).

CONCLUSION

For snare resection, MCC and LPCC did not produce significantly different tissue effects. The submucosal injectate may protect the underlying tissue, and technique may more strongly dictate the depth and extent of final injury. For margin ablation, APC was less uniform and complete compared with STSC.

Margin marking before colorectal endoscopic mucosal resection and its impact on neoplasia recurrence (with video)

BACKGROUND AND AIMS

Ablation of resection margins after EMR of large nonpedunculated colorectal polyps decreases recurrence. Margin marking before EMR (EMR-MM) may represent an alternative method to achieve a healthy resection margin. We aimed to determine the efficacy of EMR-MM in reducing neoplasia recurrence.

METHODS

We conducted a single-center historical control study of EMR cases (EMR-MM vs conventional EMR) for nonpedunculated polyps ≥20 mm between 2016 and 2021. For EMR-MM, cautery marks were placed along the lateral margins of the polyp with the snare tip. EMR was then performed to include resection of the healthy mucosa containing the marks. We compared recurrence at surveillance colonoscopy after EMR-MM versus historical control subjects. Multivariable logistic regression was performed to identify factors associated with recurrence.

RESULTS

Two hundred ten patients with 210 polyps (median size, 30 mm; interquartile range: 25-40) underwent EMR-MM (n = 74) or conventional EMR (n = 136). Patient and lesion characteristics were similar between the groups. At a median follow-up of 6 months, the recurrence rate was lower with EMR-MM (6/74; 8%) compared with historical control subjects (39/136; 29%) (P < .001). EMR-MM was not associated with an increased rate of adverse events. On multivariable analysis, EMR-MM remained the strongest predictor of recurrence (odds ratio, .20; 95% confidence interval, .13-.64; P = .003) aside from polyp size (odds ratio, 2.81; 95% confidence interval, 1.35-6.01; P = .008).

CONCLUSIONS

In this single-center historical control study, EMR-MM of large nonpedunculated colorectal polyps reduced the recurrence risk by 80% when compared with conventional EMR. This simple technique may provide an alternative to margin ablation.

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.

Indications and outcomes of endoscopic resection for non-pedunculated colorectal lesions: A narrative review

In the last years, endoscopic techniques gained a crucial role in the treatment of colorectal flat lesions. At the same time, the importance of a reliable assessment of such lesions to predict the malignancy and the depth of invasion of the colonic wall emerged. The current unsolved dilemma about the endoscopic excision techniques concerns the necessity of a reliable submucosal invasive cancer assessment system that can stratify the risk of the post-procedural need for surgery. Accordingly, this narrative literature review aims to compare the available diagnostic strategies in predicting malignancy and to give a guide about the best techniques to employ. We performed a literature search using electronic databases (MEDLINE/PubMed, EMBASE, and Cochrane Library). We collected all articles about endoscopic mucosal resection (EMR) and endoscopic submucosal dissection (ESD) registering the outcomes. Moreover, we analyzed all meta-analyses comparing EMR vs ESD outcomes for colorectal sessile or non-polypoid lesions of any size, preoperatively estimated as non-invasive. Seven meta-analysis studies, mainly Eastern, were included in the analysis comparing 124 studies and overall 22954 patients who underwent EMR and ESD procedures. Of these, eighty-two were retrospective, twenty-four perspective, nine case-control, and six cohorts, while three were randomized clinical trials. A total of 18118 EMR and 10379 ESD were completed for a whole of 28497 colorectal sessile or non-polypoid lesions > 5-10 mm in size. In conclusion, it is crucial to enhance the preoperative diagnostic workup, especially in deciding the most suitable endoscopic method for radical resection of flat colorectal lesions at risk of underlying malignancy. Additionally, the ESD necessitates further improvement because of the excessively time-consuming as well as the intraprocedural technical hindrances and related complications. We found a higher rate of en bloc resections and R0 for ESD than EMR for non-pedunculated colorectal lesions. Nevertheless, despite the lower local recurrence rates, ESD had greater perforation rates and needed lengthier procedural times. The prevailing risk for additional surgery in ESD rather than EMR for complications or oncologic reasons is still uncertain.

Does precutting prior to endoscopic piecemeal resection of large colorectal neoplasias reduce local recurrence? A KASID multicenter study

BACKGROUND

It would be expected that local recurrence could be reduced by performing precutting (with sufficient margins) prior to endoscopic piecemeal mucosal resection (EPMR). We explored the clinical outcomes and local recurrence after precutting EPMR of large colorectal neoplasias.

METHODS

Between January 2005 and December 2015, in total, 223 patients with colorectal neoplasias ≥ 2 cm in diameter removed via EPMR in four tertiary hospitals were enrolled. The patients were divided into a precut EPMR group (n = 62) and a non-precut EPMR group (n = 161). We retrospectively evaluated clinical outcomes and factors associated with local recurrence.

RESULTS

The mean total procedure time was significantly shorter in the non-precut EPMR group than in the precut EPMR group. However, the number of pieces, and the complete resection and recurrence rates, did not differ significantly [for the latter, precut 8.1% vs. non-precut 9.9%, P = 0.668]. The complete resection rate, number of pieces, and use of argon plasma coagulation (APC) were significantly associated with the local recurrence rate on univariate analysis. In the Cox's proportional hazards model, prophylactic APC [hazard ratio 0.307, 95% confidence interval (CI) 0.114-0.823; P = 0.019] and complete resection rate (odds ratio 0.083, 95% CI 0.011-0.655; P = 0.018) were significantly associated with the local recurrence rate.

CONCLUSION

Precutting prior to EPMR did not significantly reduce the local recurrence rate or the number of resected pieces. Histologically complete resection, reducing the number of pieces, and prophylactic APC seem to be important in terms of reducing local recurrence.

Outcomes of Thermal Ablation of the Mucosal Defect Margin After Endoscopic Mucosal Resection: A Prospective, International, Multicenter Trial of 1000 Large Nonpedunculated Colorectal Polyps

BACKGROUND & AIMS

Thermal ablation of the defect margin after endoscopic mucosal resection (EMR-T) for treating large (≥20 mm) nonpedunculated colorectal polyps (LNPCPs) has shown efficacy in a randomized trial, with a 4-fold reduction, in residual or recurrent adenoma (RRA) at first surveillance colonoscopy (SC1). The clinical effectiveness of this treatment, in the real world, remains unknown.

METHODS

We sought to evaluate the effectiveness of EMR-T in an international multicenter prospective trial (NCT02957058). The primary endpoint was the frequency of RRA at SC1. Detailed demographic, procedural, and outcome data were recorded. Exclusion criteria were LNPCPs involving the ileo-caecal valve, the appendiceal orifice, and circumferential LNPCPs.

RESULTS

During 51 months (May 2016-August 2020) 1049 LNPCPs in 1049 patients (median size, 35 mm; interquartile range, 25-45 mm; right colon location, 53.5%) were enrolled. Uniform completeness of EMR-T was achieved in 989 LNPCPs (95.4%). In this study, 755/803 (94.0%) eligible LNPCPs underwent SC1 (median time to SC1, 6 months; interquartile range, 5-7 months). For LNPCPs that underwent complete EMR-T, the frequency of RRA at SC1 was 1.4% (10/707).

CONCLUSIONS

In clinical practice, EMR-T is a simple, inexpensive, and highly effective auxiliary technique that is likely to significantly reduce RRA at first surveillance. It should be universally used for the management of LNPCPs after EMR. https://clinicaltrials.gov; Clinical Trial Number, NCT02957058.

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.

Spray coagulation with snare-tip versus argon plasma coagulation: An ex vivo study evaluating tissue effects

Background and study aims  Argon plasma coagulation (APC) is an effective and safe modality for many gastrointestinal conditions requiring hemostasis and/or ablation. However, it can be quite costly. A potentially more cost-effective alternative is snare-tip spray coagulation (SC). This study aimed to determine whether SC would be a safe and effective alternative to APC using an ex-vivo model. Methods  Using two resected porcine stomach, 36 randomized gastric areas were ablated for 2 seconds with either APC at 1.0 L/min 20 W (APC20) and 1.4 L/min 40 W (APC40) or SC with Effect 2 60 W (SC60) and 80 W (SC80) from 3 mm. Extent of tissue injury was then analyzed histopathologically. Results  The mean coagulation depth was 790 ± 159 µm and 825 ± 467 µm for SC60 (n = 9) and SC80 (n = 8), respectively. This was compared to 539 ± 151 µm for APC20 (n = 8) and 779 ± 267 µm for APC40 (n = 9). Mean difference (MD) in coagulation depth between SC60 and APC40 was 12 µm (95 % confidence interval [CI], -191 to 214 µm; P  = 0.91) and was 47 µm (95 %CI, -162 to 255 µm; P  = 0.81) between SC80 and APC40. There was a greater depth of injury with APC40 (MD, 240 µm; 95 %CI, 62 to 418 µm; P  = 0.04) and with SC60 (MD, 252 µm; 95 %CI, 141 to 362 µm; P  = 0.004) when compared to APC20. Mean cross-sectional area of coagulation was 2.39 ± 0.852 mm² for SC60 and 2.54 ± 1.83 mm² for SC80 compared to 1.22 ± 0.569 mm² for APC20 and 1.99 ± 0.769 mm² for APC40. Seventy-eight percent reached the muscularis mucosa (MM) and 11 % the submucosa in the SC60 group compared to 50 % and 38 % in SC80 and 56 % and 11 % in APC40, respectively. Thirty-eight percent of APC20 specimens reached the MM. The muscularis propria was unaffected. Conclusions  This small ex-vivo study suggests that SC60 and SC80 may be safe alternatives to APC40 with comparable coagulation depths and area effects.

When and How To Use Endoscopic Tattooing in the Colon: An International Delphi Agreement

BACKGROUND & AIMS

There is a lack of clinical studies to establish indications and methodology for tattooing, therefore technique and practice of tattooing is very variable. We aimed to establish a consensus on the indications and appropriate techniques for colonic tattoo through a modified Delphi process.

METHODS

The baseline questionnaire was classified into 3 areas: where tattooing should not be used (1 domain, 6 questions), where tattooing should be used (4 domains, 20 questions), and how to perform tattooing (1 domain 20 questions). A total of 29 experts participated in the 3 rounds of the Delphi process.

RESULTS

A total of 15 statements were approved. The statements that achieved the highest agreement were as follows: tattooing should always be used after endoscopic resection of a lesion with suspicion of submucosal invasion (agreement score, 4.59; degree of consensus, 97%). For a colorectal lesion that is left in situ but considered suitable for endoscopic resection, tattooing may be used if the lesion is considered difficult to detect at a subsequent endoscopy (agreement score, 4.62; degree of consensus, 100%). A tattoo should never be injected directly into or underneath a lesion that might be removed endoscopically at a later point in time (agreement score, 4.79; degree of consensus, 97%). Details of the tattoo injection should be stated clearly in the endoscopy report (agreement score, 4.76; degree of consensus, 100%).

CONCLUSIONS

This expert consensus has developed different statements about where tattooing should not be used, when it should be used, and how that should be done.

Safety and efficacy of band ligation and auto-amputation as adjunct to EMR of colonic large laterally spreading tumors, and polyps not amenable to routine polypectomy

Introduction:

The safety and efficacy of colonic band ligation and auto-amputation (1) as adjunct to endoscopic mucosal resection of large laterally spreading tumors and (2) for polyps not amenable to routine polypectomy due to polyp burden or difficult location remain unknown.

Methods:

An institutional review board–approved retrospective single-institution study was undertaken of patients undergoing colonic band ligation and auto-amputation from 2014 to date. Patients with indications of ‘endoscopic mucosal resection for laterally spreading tumors’ and ‘polyp not amenable to snare polypectomy’ were included in the study. Data were collected on patient demographics, colonoscopy details (laterally spreading tumors/polyp characteristics, therapies applied, complications), pathology results, and follow-up (polyp eradication based on endoscopic appearance and biopsy results).

Results:

Patients undergoing endoscopic mucosal resection for laterally spreading tumors: Thirty-two patients (31 males, aged 68 ± 9.17 years) underwent endoscopic mucosal resection-band ligation and auto-amputation of 34 laterally spreading tumors (40 ± 10.9 mm). A median of 2 ± 1.09 bands were placed. Follow-up colonoscopy and biopsy results confirmed complete eradication in 21 laterally spreading tumors (70%). Nine (30%) laterally spreading tumors required additional endoscopic therapy to achieve complete eradication. Four (13%) patients underwent surgery for cancer, and two of them had resection specimens negative for cancer or residual adenoma. One patient suffered post-polypectomy syndrome. Patients undergoing band ligation and auto-amputation for polyps not amenable to snare polypectomy: Seven patients underwent band ligation and auto-amputation due to serrated polyposis syndrome (one patient) and innumerable polyps, or polyps in difficult locations (extension into diverticula: two patients; terminal ileum: two patients; appendiceal orifice: one patient; anal canal: one patient). The patient with serrated polyposis syndrome achieved dramatic decrease in polyp burden, but not eradication. Follow-up in five of the six remaining patients documented polyp eradication. The patient with serrated polyposis syndrome suffered from rectal pain and tenesmus following placement of 18 bands.

Conclusions:

Band ligation and auto-amputation in the colon may be a safe and effective adjunct to current endoscopic mucosal resection and polypectomy methods and warrants further study.

Plain Language Summary

Colonoscopy with rubber band placement to aid in complete removal of large polyps and polyps in technically challenging locations

Colonoscopy is a commonly performed procedure for the early detection of colon and rectal cancer, and prevention through polyp removal.During colonoscopy, sometimes situations are encountered making polyp removal difficult. These can include the presence of larger polyps or the location of a polyp in an area that makes removal technically challenging or high risk.A particularly challenging situation arises when after extensive effort there is still polyp tissue remaining that cannot be removed using routine techniques. We are interested in exploring a technique which involves the placement of a rubber band after sucking a small area of the colon lining into a cap loaded onto the tip of the colonoscope. With time the rubber band strangulates the tissue and falls off along with captured tissue and passes out of the colon naturally.To assess the effectives of this technique we studied patients that have undergone this procedure at our GI unit. We identified 32 patients with 34 large polyps between 4cm to 6cm that we placed rubber bands on polyp tissue after we were unable to completely remove the polyp. On their follow up colonoscopy, complete polyp removal was successful in 21 polyps. We were also able to achieve complete polyp removal in 9 of the remaining large polyps after additional treatment. Four patients underwent surgery because cancer was found in analysis of polyp tissue.In 5 of 6 patients with polyps in difficult locations (e.g. partly within the lumen of the appendix), placement of a rubber band led to complete removal of polyp tissue.Two patients in our study population had mild adverse events that were managed with simple measures.We believe our results show promise for our described technique and this technique should be tested in larger studies.

Can prophylactic argon plasma coagulation reduce delayed post-papillectomy bleeding? A prospective multicenter trial

BACKGROUND AND AIM

Endoscopic post-papillectomy bleeding occurs in 3% to 20% of the cases, and delayed bleeding is also problematic. However, there is no consensus on how to reduce delayed post-papillectomy bleeding. The aim of this study was to evaluate the efficacy of prophylactic argon plasma coagulation (APC) to minimize delayed bleeding and reduce the persistence of residual tumors after endoscopic papillectomy.

METHODS

In a prospective pilot study of patients with benign ampullary tumors, the prophylactic APC group underwent APC at the resection margin following a conventional snaring papillectomy. Then, 24 h later after the papillectomy, all patients underwent a follow-up duodenoscopy to identify post-papillectomy bleeding and were followed up until 12 months. The main outcomes were the delayed (≥24 h) post-papillectomy bleeding rate and the tumor persistence rate.

RESULTS

The delayed post-papillectomy bleeding rate was 30.8% (8/26) in the prophylactic APC group and 21.4% (6/28) in the non-APC group (P = 0.434). The post-procedure pancreatitis rates were 23.1% (6/26) and 35.7% (10/28), respectively (P = 0.310). The rate of tumor persistence did not differ between the two groups at 1 month (12.5% vs 7.4%, P = 0.656), 3 months (4.2% vs 3.7%, P = 1.00), 6 months (8.3% vs 3.7%, P = 0.595), and 12 months (0% vs 3.7%, P = 1.00). There were no procedure-related mortalities or serious complications.

CONCLUSION

Prophylactic APC may not be effective in reducing delayed post-papillectomy bleeding or remnant tumor ablation immediately after conventional papillectomy (Clinical trial registration-cris.nih.go.kr; KCT0001955).

Therapeutic Upper Gastrointestinal Endoscopy in Pediatric Gastroenterology

This paper seeks to give a broad overview of pediatric upper gastrointestinal (GI) pathologies that we are now able to treat endoscopically, acquired or congenital, and we hope this delivers the reader an impression of what is increasingly available to pediatric endoscopists and their patients.

Devices and techniques for endoscopic treatment of residual and fibrotic colorectal polyps (with videos)

BACKGROUND AND AIMS

Residual neoplasia after macroscopically complete EMR of large colon polyps has been reported in 10% to 32% of resections. Often, residual polyps at the site of prior polypectomy are fibrotic and nonlifting, making additional resection challenging.

METHODS

This document reviews devices and methods for the endoscopic treatment of fibrotic and/or residual polyps. In addition, techniques reported to reduce the incidence of residual neoplasia after endoscopic resection are discussed.

RESULTS

Descriptions of technologies and available outcomes data are summarized for argon plasma coagulation ablation, snare-tip coagulation, avulsion techniques, grasp-and-snare technique, EndoRotor endoscopic resection system, endoscopic full-thickness resection device, and salvage endoscopic submucosal dissection.

CONCLUSIONS

Several technologies and techniques discussed in this document may aid in the prevention and/or resection of fibrotic and nonlifting polyps.

Cap-fitted endoscopic mucosal resection of ≥ 20 mm colon flat lesions followed by argon plasma coagulation results in a low adenoma recurrence rate

Background and study aims  Endoscopic mucosal resection (EMR) is increasingly used for the treatment of large colonic polyps (≥ 20 mm). A drawback of EMR is local adenoma recurrence. Therefore, we studied the impact of argon plasma coagulation (APC) of the EMR edge on local adenoma recurrence. Patients and methods  This was a retrospective study of patients with laterally spreading tumors (LST) ≥ 20 mm, who underwent EMR from January 2009 to August 2018 and follow-up endoscopic assessment. A cap-fitted endoscope was used to assess completeness of resection by systematically inspecting the EMR defect for any macroscopic disease. This was followed by forced APC of the resection edge followed by clip closure of the defect. Surveillance colonoscopy was performed at 6 months after resection to detect recurrence. Results  Two hundred forty-six patients met the inclusion criteria. Most were female (53 %) and white (80 %), with a Median age of 64 years. Median polyp size was 35 mm (interquartile range, 30-45 mm). Most polyps were located in the right colon (77 %) and were removed by piecemeal EMR (70 %). Eleven patients (5 %) had residual tumor at the resection site. Conclusions  We observed low adenoma recurrence after argon plasma coagulation of the EMR edge with a cap fitted colonoscope in patients with LST ≥ 20 mm of the colon, which requires further validation in a randomized controlled study.

Long-term outcomes of endoscopically resected laterally spreading tumors with a positive histological lateral margin

BACKGROUND

With advances in diagnostic endoscopy, the incidence of superficial colorectal tumors, including laterally spreading tumors (LSTs), has increased. However, little is known about the long-term results of LSTs with positive lateral margin after endoscopic treatment. This study aimed to evaluate the long-term clinical outcomes and risk factors for local recurrence of LSTs with positive lateral margin after initial endoscopic resection.

METHODS

We performed a retrospective analysis of the medical records of 324 patients who had 363 LSTs with positive lateral margin after endoscopic resection at a tertiary academic medical center. The medical records from 2011 to 2015 were analyzed. Local recurrence was confirmed through endoscopic finding and subsequent biopsy analysis. We assessed the local recurrence rate and performed multivariate analyses to identify the factors associated with local recurrence.

RESULTS

Follow-up colonoscopy was performed in 176 of 363 LSTs. The local recurrence rate was 6.3% (11/176), with a median (interquartile range [IQR]) follow-up period of 19.8 (12.4-46.5) months. In multivariate analysis, local recurrence was associated with piecemeal resection (odds ratio [OR] 6.62, 95% confidence interval [CI] 1.28-34.33; p = 0.024) and inversely associated with thermal ablation (OR 0.033, 95% CI 0.00-0.45; p = 0.011). At surveillance colonoscopy, histology of the recurrent tumor was adenoma in 10 (90.9%) of 11; these were treated endoscopically.

CONCLUSIONS

In this retrospective study, we found that endoscopically resected LSTs with positive lateral margin have a low recurrence rate. Piecemeal resection was associated with higher local recurrence, and thermal ablation was inversely associated with local recurrence. Endoscopic resection with positive lateral margin combined with thermal ablation leads to a low recurrence rate.

Clip Closure Prevents Bleeding After Endoscopic Resection of Large Colon Polyps in a Randomized Trial

BACKGROUND & AIMS

Bleeding is the most common severe complication after endoscopic mucosal resection of large colon polyps and is associated with significant morbidity and cost. We examined whether prophylactic closure of the mucosal defect with hemoclips after polyp resection reduces the risk of bleeding.

METHODS

We performed a multicenter, randomized trial of patients with a large nonpedunculated colon polyp (≥20 mm) at 18 medical centers in North America and Spain from April 2013 through October 2017. Patients were randomly assigned to groups that underwent endoscopic closure with a clip (clip group) or no closure (control group) and followed. The primary outcome, postprocedure bleeding, was defined as a severe bleeding event that required hospitalization, a blood transfusion, colonoscopy, surgery, or another invasive intervention within 30 days after completion of the colonoscopy. Subgroup analyses included postprocedure bleeding with polyp location, polyp size, or use of periprocedural antithrombotic medications. We also examined the risk of any serious adverse event.

RESULTS

A total of 919 patients were randomly assigned to groups and completed follow-up. Postprocedure bleeding occurred in 3.5% of patients in the clip group and 7.1% in the control group (absolute risk difference [ARD] 3.6%; 95% confidence interval [CI] 0.7%-6.5%). Among 615 patients (66.9%) with a proximal large polyp, the risk of bleeding in the clip group was 3.3% and in the control group was 9.6% (ARD 6.3%; 95% CI 2.5%-10.1%); among patients with a distal large polyp, the risks were 4.0% in the clip group and 1.4% in the control group (ARD -2.6%; 95% CI -6.3% to -1.1%). The effect of clip closure was independent of antithrombotic medications or polyp size. Serious adverse events occurred in 4.8% of patients in the clip group and 9.5% of patients in the control group (ARD 4.6%; 95% CI 1.3%-8.0%).

CONCLUSIONS

In a randomized trial, we found that endoscopic clip closure of the mucosal defect following resection of large colon polyps reduces risk of postprocedure bleeding. The protective effect appeared to be restricted to large polyps located in the proximal colon. ClinicalTrials.gov no: NCT01936948.

Safety and efficacy of hot avulsion as an adjunct to EMR (with videos)

BACKGROUND AND AIMS

Excision of all visible neoplastic tissue is the goal of EMR of colorectal laterally spreading tumors. Flat and fibrotic tissue can resist snaring. Ablation of visible polyps is associated with high recurrence rates. Avulsion is a technique to continue resection when snaring fails.

METHODS

We retrospectively analyzed colonic EMRs of 564 consecutive referred polyps between 2015 and 2017. Hot avulsion was used when snaring was unsuccessful. Polyps treated with and without avulsion were compared.

RESULTS

Hot avulsion was used in 20.9% (n = 112) of all resected lesions. The recurrence rates on follow-up colonoscopy were 17.52% in the avulsion group versus 16.02% in the non-avulsion group (P = .76). Hot avulsion was associated with a trend toward higher rates of delayed hemorrhage (5.35% vs 2.58%; P = .15) and post-coagulation syndrome (1.8% vs 0.47%; P = .15), but polyps treated with any avulsion were larger than those in which no avulsion was used (P < .001). There were an insufficient number of adverse events to perform a multivariable analysis to test the effects of avulsion, size, and location on the risk of overall adverse events.

CONCLUSIONS

Unlike previous reports of using argon plasma coagulation to treat visible polyps during EMR, hot avulsion of visible/fibrotic neoplasia was associated with similar EMR efficacy compared with cases that did not require hot avulsion. The safety profile of hot avulsion appears acceptable.

Thermal Ablation of Mucosal Defect Margins Reduces Adenoma Recurrence After Colonic Endoscopic Mucosal Resection

BACKGROUND & AIMS

Colorectal cancer (CRC) can be prevented by colonoscopy and polypectomy. Endoscopic mucosal resection (EMR) is performed to remove large laterally spreading colonic lesions that have a high risk of progression to CRC. Endoscopically invisible micro-adenomas at the margins of the EMR site might contribute to adenoma recurrence, which occurs in 15% to 30% of patients who undergo surveillance. We aimed to determine the efficacy of adjuvant thermal ablation of the EMR mucosal defect margin in reducing polyp recurrence.

METHODS

We performed a prospective study of 390 patients with large laterally spreading colonic lesions (≥ 20 mm, n = 416) referred for EMR at 4 tertiary centers in Australia. After complete lesion excision by EMR, lesions were randomly assigned to thermal ablation of the post-EMR mucosal defect margin (n = 210) or no additional treatment (controls, n = 206). We performed surveillance colonoscopies with standardized photo documentation and biopsies of the scar after 5 to 6 months. Patient, procedure, and lesion characteristics were similar between the groups. The primary endpoint was detection of lesion recurrence at first surveillance colonoscopy.

RESULTS

A significantly lower proportion of patients who received thermal ablation of the post-EMR mucosal defect margin had evidence of recurrence at first surveillance colonoscopy (10/192, 5.2%) than controls (37/176, 21.0%) (P < .001). The relative risk of recurrence in the thermal ablation group was 0.25 compared with the control group (95% confidence interval 0.13-0.48). Rates of adverse events were similar between the groups.

CONCLUSIONS

In a multicenter randomized trial, thermal ablation of the post-EMR mucosal defect margin significantly reduced polyp recurrence at first surveillance colonoscopy, compared with no additional treatment. Routine implementation of this simple and safe technique could increase the utility of EMR, decrease surveillance burdens, and reduce morbidity and mortality from CRC. ClinicalTrials.gov no: NCT01789749.

Interval colorectal cancer: a challenging field in colorectal cancer

Accumulated evidence has shown that colonoscopy may not be a perfect tool in screening and reducing the incidence of the colorectal cancer (CRC), because interval CRC (I-CRC), a specific subgroup of CRCs, has been challenging the traditional detection technology in recent years. I-CRC is accounting for an increasing proportion in CRCs. However, the effective procedures to prevent and supervise I-CRC need to be explored. In this review, we summarized the incidence, causes, risk factors, characteristics and management of I-CRC. It would promote the awareness of the special value in the education and training for the gastroenterologists, which plays an important role in conquering CRC.

A novel summary report of colonoscopy: timeline visualization providing meaningful colonoscopy video information

PURPOSE

The colonoscopy adenoma detection rate depends largely on physician experience and skill, and overlooked colorectal adenomas could develop into cancer. This study assessed a system that detects polyps and summarizes meaningful information from colonoscopy videos.

METHODS

One hundred thirteen consecutive patients had colonoscopy videos prospectively recorded at the Seoul National University Hospital. Informative video frames were extracted using a MATLAB support vector machine (SVM) model and classified as bleeding, polypectomy, tool, residue, thin wrinkle, folded wrinkle, or common. Thin wrinkle, folded wrinkle, and common frames were reanalyzed using SVM for polyp detection. The SVM model was applied hierarchically for effective classification and optimization of the SVM.

RESULTS

The mean classification accuracy according to type was over 93%; sensitivity was over 87%. The mean sensitivity for polyp detection was 82.1%, and the positive predicted value (PPV) was 39.3%. Polyps detected using the system were larger (6.3 ± 6.4 vs. 4.9 ± 2.5 mm; P = 0.003) with a more pedunculated morphology (Yamada type III, 10.2 vs. 0%; P < 0.001; Yamada type IV, 2.8 vs. 0%; P < 0.001) than polyps missed by the system. There were no statistically significant differences in polyp distribution or histology between the groups. Informative frames and suspected polyps were presented on a timeline. This summary was evaluated using the system usability scale questionnaire; 89.3% of participants expressed positive opinions.

CONCLUSIONS

We developed and verified a system to extract meaningful information from colonoscopy videos. Although further improvement and validation of the system is needed, the proposed system is useful for physicians and patients.

Argon and helium plasma coagulation of porcine liver tissue

Objective

Argon plasma coagulation (APC) and helium plasma coagulation (HPC) are electrosurgical techniques that provide noncontact monopolar electrothermal haemostasis. Although these techniques have been widely used clinically during the last three decades, their in vivo effects on liver tissue remain unclear.

Methods

We investigated the effects of different power levels (10–100 W) of APC and HPC on liver coagulation in 11 Landrace pigs. Capillary blood flow and capillary blood flow velocity were recorded with a combined laser Doppler flowmeter and spectrophotometer. The temperature, clinical biochemical parameters, blood gas parameters, bile duct-sealing effect, and coagulation depth were measured.

Results

APC and HPC significantly reduced the capillary blood flow and capillary blood flow velocity compared with baseline flow. No significant temperature change was measured on the liver surface immediately after coagulation. The clinical biochemical and blood gas parameters were not different before and after coagulation. The coagulation depth was positively correlated with the device power setting.

Conclusions

These results prove that APC and HPC provide sufficient superficial haemostasis. No significant systemic effects occurred following coagulation. The depth of the coagulation effect can be controlled through selection of the output power level.

Polyp Resection - Controversial Practices and Unanswered Questions

Detection and complete removal of precancerous neoplastic polyps are central to effective colorectal cancer screening. The prevalence of neoplastic polyps in the screening population in the United States is likely >50%. However, most persons with neoplastic polyps are never destined to develop cancer, and do not benefit for finding and removing polyps, and may only be harmed by the procedure. Further 70-80% of polyps are diminutive (≤5 mm) and such polyps almost never contain cancer. Given the questionable benefit, the high-cost and the potential risk changing our approach to the management of diminutive polyps is currently debated. Deemphasizing diminutive polyps and shifting our efforts to detection and complete removal of larger and higher-risk polyps deserves discussion and study. This article explores three controversies, and emerging concepts related to endoscopic polyp resection. First, we discuss challenges of optical resect-and-discard strategy and possible alternatives. Second, we review recent studies that support the use of cold snare resection for ≥5 mm polyps. Thirdly, we examine current evidence for prophylactic clipping after resection of large polyps.

Adenoma recurrence after piecemeal colonic EMR is predictable: the Sydney EMR recurrence tool

BACKGROUND AND AIMS

EMR is the primary treatment of large laterally spreading lesions (LSLs) in the colon. Residual or recurrent adenoma (RRA) is a major limitation. We aimed to identify a robust method to stratify the risk of RRA.

METHODS

Prospective multicenter data on consecutive LSLs ≥20 mm removed by piecemeal EMR from 8 Australian tertiary-care centers were included (September 2008 until May 2016). A logistic regression model for endoscopically determined recurrence (EDR) was created on a randomly selected half of the cohort to yield the Sydney EMR recurrence tool (SERT), a 4-point score to stratify the incidence of RRA based on characteristics of the index EMR. SERT was validated on the remainder of the cohort.

RESULTS

Analysis was performed on 1178 lesions that underwent first surveillance colonoscopy (SC1) (median 4.9 months, interquartile range [IQR] 4.9-6.2). EDR was detected in 228 of 1178 (19.4%) patients. LSL size ≥40 mm (odds ratio [OR] 2.47; P < .001), bleeding during the procedure (OR 1.78; P = .024), and high-grade dysplasia (OR 1.72; P = .029) were identified as independent predictors of EDR and allocated scores of 2, 1, and 1, respectively to create SERT. Lesions with SERT scores of 0 (SERT = 0) had a negative predictive value of 91.3% for RRA at SC1, and SERT was shown to stratify RRA to specific follow-up intervals by using Kaplan Meier curves (log-rank P < .001).

CONCLUSIONS

Guidelines recommend SC1 within 6 months of EMR. SERT accurately stratifies the incidence of RRA after EMR. SERT = 0 lesions could safely undergo first surveillance at 18 months, whereas lesions with SERT scores between 1 and 4 (SERT 1-4) require surveillance at 6 and 18 months. (Clinical trial registration number: NCT01368289.).

Successful treatment of proton pump inhibitor induced sporadic fundic gland polyps with an argon plasma coagulator in a patient with polycythaemia vera

•

Proton pump inhibitor (PPI) use is associated with the development of fundic gland polyps (FGPs).

•

Discontinuing PPI is associated with regression of FGPs, but not in patients with polycythaemia vera.

•

A rare case of non-respondent FGPs after discontinuing PPI use was successfully treated using APC.

•

The mechanism involved in the interaction between FGP and polycytheamia vera remains unknown.

Introduction

Proton pump inhibitor (PPI) use is associated with the development of fundic gland polyps (FGPs); discontinuing PPIs is associated with regression of FGPs. Here, we report a rare case of non-respondent FGPs after discontinuation of PPI that were successfully treated using an argon plasma coagulator (APC).

Presentation of case

We present the case of a 68-year-old woman with a history of polycytheamia vera. She also had gastroesophageal reflux disease (GERD) and had been taking 10 mg of omeprazole daily for the past three years. Esophagogastroduedenoscopy (GF) revealed over 100 pedunculated polyps in the gastric body and fundus. Histological examination of the specimens showed dilated oxyntic glands with flattened parietal and mucous cells. Based on these findings and the clinical history, a diagnosis of FGPs was made. Omeprazole use was then discontinued. Repeat GF performed 6 months and 1 year later showed a significant increase in the number and size of the polyps. APC treatment was performed every 6 months for 3 years. Further GF showed a significant decrease in the number and size of the FGPs 4 years after discontinuing PPI.

Discussion

We conclude that PPI use is a strong risk factor for the development of FGPs and discontinuing PPI is associated with regression of FGPs, but not in patients with polycythaemia vera. However, the mechanism involved in the interaction between FGP and polycytheamia vera remains unknown.

Conclusion

Non-respondent FGPs after discontinuation of PPI use may be successfully treated using APC.

Optimizing Resection of Large Colorectal Polyps

OPINION STATEMENT

Polypectomy reduces the incidence and mortality of colorectal cancer (CRC). The widespread adoption of CRC screening, more rigorous colonoscopy techniques, and advancements in endoscopic imaging have led to a greater awareness of complex polyps. Whereas surgery was once considered necessary for many large sessile or laterally spreading lesions (LSLs) in the colorectum, the majority can now be removed endoscopically. Endoscopic mucosal resection (EMR) is an established technique for treatment of colorectal LSLs. When performed by experts, EMR is highly effective and safe and can be completed in an outpatient or day-stay setting. Advancements in EMR effectiveness encompass a better understanding of the factors leading to post-EMR recurrence, protocols to recognize and treat it, and interventions that prevent recurrent or residual adenoma. New techniques for treating intra-procedural bleeding and a novel classification system to identify and inform proactive management of deep mural injury enhance the safety profile of EMR. However, each of these incremental advancements necessitates a meticulous and systematic approach that only committed and properly trained endoscopists can master. While alternative interventions such as endoscopic submucosal dissection (ESD) offer potential advantages over EMR, the added procedural complexity, risks, and costs limit the relevance of ESD to a minority of lesions in the colorectum. This article reviews the expanding body of evidence supporting EMR as the first-line treatment of colorectal LSLs ≥20 mm.