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

Multicentre randomised controlled trial of a self-assembling haemostatic gel to prevent delayed bleeding following endoscopic mucosal resection (PURPLE Trial)

BACKGROUND

Prophylactic application of a haemostatic gel to the resection field may be an easy way to prevent delayed bleeding, a frequent complication after endoscopic mucosal resection (EMR).

OBJECTIVE

We aimed to evaluate if the prophylactic application of a haemostatic gel to the resection field directly after EMR can reduce the rate of clinically significant delayed bleeding events.

DESIGN

We conducted a prospective randomised trial of patients undergoing hot-snare EMR of flat lesions in the duodenum (≥10 mm) and colorectum (≥20 mm) at 15 German centres. Prophylactic clip closure was not allowed, but selective clipping or coagulation could be used prior to randomisation to treat intraprocedural bleeding or for prophylactic closure of visible vessels. Patients were randomised to haemostatic gel application or no prophylaxis. The primary endpoint was delayed bleeding within 30 days.

RESULTS

The trial was stopped early due to futility after an interim analysis. The primary endpoint was analysed in 232 patients (208 colorectal, 26 duodenal). Both groups were comparable in age, sex, comorbidities and lesion characteristics. Preventive measures, such as selective clipping or coagulation, were applied prior to randomisation in 51.9% of cases, with no difference between groups. Delayed bleeding occurred in 14 cases (11.7%; 95% CI 7.1% to 18.6%) after Purastat and in 7 cases (6.3%; 95% CI 3.1% to 12.3%) in the control group (p=0.227), with no difference between colorectal and duodenal subgroups.

CONCLUSION

The application of a haemostatic gel following EMR of large flat lesions in the duodenum and colorectum does not reduce the rate of delayed bleeding.

Recurrence after piecemeal hot-snare endoscopic mucosal resection of 10-20-mm nonpedunculated colorectal polyps: a multicenter cohort study

Guidelines are equivocal on the need for early surveillance colonoscopy (ESC) after piecemeal endoscopic mucosal resection (pEMR) of 10-20-mm nonpedunculated colorectal polyps (NPCPs). This study assessed recurrence rates and associated factors at ESC following hot-snare pEMR of 10-20-mm NPCPs.A retrospective, multicenter cohort study was performed at five hospitals in the Netherlands. Patients undergoing pEMR of 10-20-mm NPCPs (2014-2021) and referred for ESC (range 3-9 months) were included. The primary outcome was recurrence rate at ESC. Secondary outcomes included scar identification rates, both overall and at tattooed sites. A mixed-effects model was used to identify factors associated with recurrence.389 patients undergoing pEMR of 426 NPCPs 10-20 mm (median 15 mm, interquartile range 12.8-20.0 mm) were included. Overall, 262 scars (61.5%; 95%CI 56.8-66.0) and 81.6% of tattooed sites were identified at ESC. The recurrence rate was 35/426 (8.2%; 95%CI 6.0-11.2) overall and 35/262 (13.4%; 95%CI 9.8-18.0) when the scar was identified. Median recurrence size was 5 mm, without high grade dysplasia. No NPCP characteristics were associated with recurrence.This real-world study found a substantial recurrence rate after hot-snare pEMR of NPCPs sized 10-20mm at ESC. ESC scar identification was moderate but improved with tattoo placement. Although early surveillance could be considered to avoid missing recurrence, the small recurrence size and absence of high grade dysplasia suggest that modestly extending the interval beyond that of our study may still allow timely detection of recurrences and metachronous lesions.

Cold snare endoscopic resection for large colon polyps: a randomised trial

BACKGROUND

Complications of endoscopic mucosal resection (EMR) of large colorectal polyps remain a concern.

OBJECTIVE

We aimed to compare safety and efficacy of cold EMR (without electrocautery) to hot EMR (with electrocautery) of large colorectal polyps.

DESIGN

In this multicentre randomised trial, patients with any large (≥20 mm) non-pedunculated colon polyp were assigned to cold or hot EMR (primary intervention), and to submucosal injection with a viscous or non-viscous solution (secondary intervention) following a 2×2 design. The primary outcome was the rate of severe adverse events (SAEs). The secondary outcome was polyp recurrence. In this study, we report results of the primary intervention.

RESULTS

660 patients were randomised and analysed. An SAE was observed in 2.1% of patients in the cold EMR group and in 4.3% in the hot EMR group (p=0.10) (per protocol analysis 1.4 vs 5.0%, p=0.017) with fewer perforations following cold EMR (0%) compared with hot EMR (1.6%, p=0.028). Postprocedure bleeding did not differ (1.5% vs 2.2%, p=0.57). The effect of cold resection was independent of the type of submucosal injection solution, polyp size or antithrombotic medications. Recurrence was detected in 27.6% and 13.6% in the cold and hot EMR groups, respectively (p<0.001). Recurrence was not significantly different for 20-29 mm polyps (18.6% vs 13.4%, p=0.24) and for sessile serrated polyps (14.1% vs 8.5%, p=0.33).

CONCLUSION

Universal application of cold EMR did not significantly lower SAEs (unless cold EMR could be completed) and doubled the recurrence rate compared with hot EMR.

TRIAL REGISTRATION DETAILS

ClinicalTrials.gov, number: NCT03865537.

Cold snare polypectomy versus hot endoscopic mucosal resection for large nonpedunculated colorectal polyps: a systematic review and meta-analysis of randomized controlled trials

This meta-analysis of randomized controlled trials (RCTs) aimed to compare the risk of recurrence and adverse events (AEs) between cold snare polypectomy (CSP) and hot endoscopic mucosal resection (H-EMR) for large nonpedunculated colorectal polyps (LNPCPs).A systematic search of Medline, Embase, and Cochrane Library databases until August 2024 was performed for studies comparing recurrence, bleeding, and perforation rates between CSP and H-EMR for LNPCPs ≥15 mm. A random-effects meta-analysis, with heterogeneity measured with I2, was conducted to generate pooled risk ratios (RRs) with 95%CIs.Four RCTs comprising 1516 LNPCPs (766 CSP and 750 H-EMR) in 1442 patients were included in the quantitative analysis. CSP demonstrated a higher recurrence risk at first surveillance colonoscopy than H-EMR in the pooled analysis (22.6% vs. 10.8%; RR 1.98; 95%CI 1.22-3.21; P = 0.02; moderate certainty evidence), corresponding to a number needed to harm of 9. Regarding AEs, CSP demonstrated a 67% reduced risk of delayed bleeding (1.2% vs. 3.9%; RR 0.33; 95%CI 0.12-0.89; P = 0.03; high certainty evidence), corresponding to a number needed to treat of 37. Although CSP appeared to reduce the risk of intraprocedural bleeding (10.0% vs. 19.8%; RR 0.30, 95%CI 0-52 256, P = 0.42), the wide confidence interval from the random-effects model included 1. There were no intraprocedural or delayed perforations in the CSP group.CSP has nearly double the recurrence risk of H-EMR for LNPCPs; however, its superior safety profile may make it a preferable option for patients where procedural safety is prioritized over radicality, such as those with extensive co-morbidities.

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).

Mechanisms of cutting soft tissues using snare-type tools

Cold snare polypectomy (CSP) is the predominant method for removing colonic polyps under 6 mm, utilizing snare-type tools as cutting tools. However, complete resection rates often decrease due to occasional cutting failure. Understanding the cutting mechanisms of snare-type tools is thus crucial for optimizing both the tool and procedure. Research on CSP has primarily focused on surgical case studies, with limited focus on the snare tools. This study investigates the cutting mechanisms of snare-type tools, examining the effects of cutting speed and snare properties on cutting force. The results show that the internal tissue fractures first during CSP, followed by the external tissue. High cutting speeds and thin wire ropes reduce the cutting force required and produce flatter cut cross-sections. Cold snare defect protrusions are primarily due to the high toughness and strength of the submucosa layer tissue, which impedes internal tissue fracture. These findings enhance the understanding of the internal fracture mechanism of soft tissue and provide valuable insights for optimizing snare-type tools, potentially improving the efficacy and safety of polyp resection procedures.

Impact of margin thermal ablation after cold-forceps avulsion with snare-tip soft coagulation for nonlifting large nonpedunculated colorectal polyps

Nonlifting large nonpedunculated colorectal polyps (NL-LNPCPs) account for 15% of LNPCPs and are effectively managed by endoscopic mucosal resection (EMR) with adjunctive cold-forceps avulsion with adjuvant snare-tip soft coagulation (CAST). Recurrence rates >10% at surveillance colonoscopy are however a significant limitation. We aimed to compare the outcomes of CAST plus margin thermal ablation (MTA) versus CAST alone for NL-LNPCPs.Prospective observational data on consecutive patients with NL-LNPCPs treated by EMR and CAST at a single tertiary center were retrospectively evaluated. Two cohorts were established: the pre-MTA period (January 2012-June 2017) and the MTA period (July 2017-October 2023). The primary outcome was the residual/recurrent adenoma (RRA) rate at first surveillance colonoscopy (SC1). Secondary outcomes included the RRA rate at SC2 and adverse events.Over 142 months, 300 patients underwent EMR and CAST for LNPCP: 103 lesions pre-MTA and 197 with MTA. At SC1 and SC2, recurrence was lower in the MTA cohort compared with the pre-MTA cohort (5.0% vs. 18.8% and 0.8% vs. 10.0%, respectively; both P<0.001). Adverse events were similar between the two cohorts for deep mural injury types III-V (pre-MTA 2.9% vs. MTA 5.6%; P=0.29) and delayed bleeding (pre-MTA 8.7% vs. MTA 7.1%; P=0.49). On multivariate analysis, MTA was the only variable independently associated with a reduced likelihood of recurrence (odds ratio 0.20, 95%CI 0.07-0.54; P=0.001).For NL-LNPCPs, MTA in combination with CAST is safe and effective and reduces recurrence at SC1 in comparison with CAST alone.

Prevalence of Endoscopically Curable Low-Risk Cancer Among Large (≥20 mm) Nonpedunculated Polyps in the Right Colon

BACKGROUND AND AIMS

Endoscopic submucosal dissection is increasingly promoted for the treatment of all large nonpedunculated colorectal polyps (LNPCPs) to cure potential low-risk cancers (superficial submucosal invasion without additional high-risk histopathologic features). The effect of a universal en bloc strategy on oncologic outcomes for the treatment of LNPCPs in the right colon is unknown. We evaluated this in a large Western population.

METHODS

A prospective cohort of patients referred for endoscopic resection (ER) of LNPCPs was analyzed. Patients found to have cancer after ER and those referred directly to surgery were included. The primary outcome was to determine the proportion of right colon LNPCPs with low-risk cancer.

RESULTS

Over 180 months until June 2023, 3294 sporadic right colon LNPCPs in 2956 patients were referred for ER at 7 sites (median size 30 [interquartile range 22.5-37.5] mm). A total of 63 (2.1%) patients were referred directly to surgery, and cancer was proven in 56 (88.9%). A total of 2851 (96.4%) of 2956 LNPCPs underwent ER (median size 35 [interquartile range 25-45] mm), of which 75 (2.6%) were cancers. The overall prevalence of cancer in the right colon was 4.4% (n = 131 of 2956). Detailed histopathologic analysis was possible in 115 (88%) of 131 cancers (71 after ER, 44 direct to surgery). After excluding missing histopathologic data, 23 (0.78%) of 2940 sporadic right colon LNPCPs were low-risk cancers.

CONCLUSIONS

The proportion of right colon LNPCPs referred for ER containing low-risk cancer amenable to endoscopic cure was <1%, in a large, multicenter Western cohort. A universal endoscopic submucosal dissection strategy for the management of right colon LNPCPs is unlikely to yield improved patient outcomes given the minimal impact on oncologic outcomes.

CLINICALTRIALS

gov, Numbers: NCT01368289, NCT02000141.

Endoscopic mucosal resection defect inspection for predicting recurrences: International image-based survey

Background and study aims Endoscopic mucosal resection (EMR) is a safe and minimally invasive procedure to remove colorectal non-pedunculated polyps. Recurrence rates are relatively high and differ among endoscopists. We aimed to evaluate whether endoscopists are able to predict recurrence based on thorough inspection of images of mucosal defects after an assumed complete EMR. Methods We developed an online survey in which endoscopists were invited to indicate whether they expected recurrence to develop when inspecting 30 post-EMR defect images. All EMRs were considered to be complete resections by the performing endoscopist. Participating endoscopists were scored based on the number of correct answers regarding presence or absence of recurrence found at first surveillance colonoscopy. Results A total of 140 endoscopists responded to the survey (response rate 25%). A total of 124 respondents with a mean age of 46.5 years evaluated the 30 images. The overall score in the cohort was 70%, indicating that respondents were able to correctly predict recurrence in three-quarters of cases with an overall level of certainty of 53.4%. When comparing results of experienced and less experienced endoscopists based on the number of endoscopic submucosal dissections and/or EMRs performed yearly, no difference (71% versus 69%, P = 0.23) was found. Conclusions This study shows that recurrences after presumed complete EMR can reasonably well be predicted by both experienced and less experienced endoscopists when evaluating images with mucosal defects. Thorough inspection of the post-EMR defect may reduce recurrence rates by recognizing and subsequent treatment of suspect areas.

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.

Impact of margin thermal ablation after endoscopic mucosal resection of large (≥20 mm) non-pedunculated colonic polyps on long-term recurrence

BACKGROUND AND AIMS

The efficacy of colorectal endoscopic mucosal resection (EMR) is limited by recurrence and the necessity for conservative surveillance. Margin thermal ablation (MTA) after EMR has reduced the incidence of recurrence at the first surveillance colonoscopy at 6 months (SC1). Whether this effect is durable to second surveillance colonoscopy (SC2) is unknown. We evaluated long-term surveillance outcomes in a cohort of LNPCPs that have undergone MTA.

METHODS

LNPCPs undergoing EMR and MTA from four academic endoscopy centres were prospectively recruited. EMR scars were evaluated at SC1 and in the absence of recurrence, SC2 colonoscopy was conducted in a further 12 months. A historical control arm was generated from LNPCPs that underwent EMR without MTA. The primary outcome was recurrence at SC2 in all LNPCPs with a recurrence-free scar at SC1.

RESULTS

1152 LNPCPs underwent EMR with complete MTA over 90 months until October 2022. 854 LNPCPs underwent SC1 with 29/854 (3.4%) LNPCPs demonstrating recurrence. 472 LNPCPs free of recurrence at SC1 underwent SC2. 260 LNPCPs with complete SC2 follow-up formed the control arm from January 2012 to May 2016. Recurrence at SC2 was significantly less in the MTA arm versus controls (1/472 (0.2%) vs 9/260 (3.5%); p<0.001)).

CONCLUSION

LNPCPs that have undergone successful EMR with MTA and are free of recurrence at SC1 are unlikely to develop recurrence in subsequent surveillance out to 2 years. Provided the colon is cleared of synchronous neoplasia, the next surveillance can be potentially extended to 3-5 years. Such an approach would reduce costs and enhance patient compliance.

Advanced Techniques in Therapeutic and Inflammatory Bowel Disease Colonoscopy

Colonoscopy is an essential diagnostic and therapeutic tool in the management of colorectal disease. This review explores the recent advances of colonoscopy that have revolutionized patient care in the era of minimally invasive medicine. Key areas of focus include innovations in imaging, advanced endoscopic resection techniques, and nonsurgical management of strictures. Advances in therapeutic endoscopy are especially evident in inflammatory bowel disease. As the landscape of colonoscopy continues to evolve, it will continue to play a central role in modern medicine, shaping the future of patient care, and therapeutic interventions.

International consensus on the management of large (≥20 mm) colorectal laterally spreading tumors: World Endoscopy Organization Delphi study

OBJECTIVES

There have been significant advances in the management of large (≥20 mm) laterally spreading tumors (LSTs) or nonpedunculated colorectal polyps; however, there is a lack of clear consensus on the management of these lesions with significant geographic variability especially between Eastern and Western paradigms. We aimed to provide an international consensus to better guide management and attempt to homogenize practices.

METHODS

Two experts in interventional endoscopy spearheaded an evidence-based Delphi study on behalf of the World Endoscopy Organization Colorectal Cancer Screening Committee. A steering committee comprising six members devised 51 statements, and 43 experts from 18 countries on six continents participated in a three-round voting process. The Grading of Recommendations, Assessment, Development and Evaluations tool was used to assess evidence quality and recommendation strength. Consensus was defined as ≥80% agreement (strongly agree or agree) on a 5-point Likert scale.

RESULTS

Forty-two statements reached consensus after three rounds of voting. Recommendations included: three statements on training and competency; 10 statements on preresection evaluation, including optical diagnosis, classification, and staging of LSTs; 14 statements on endoscopic resection indications and technique, including statements on en bloc and piecemeal resection decision-making; seven statements on postresection evaluation; and eight statements on postresection care.

CONCLUSIONS

An international expert consensus based on the current available evidence has been developed to guide the evaluation, resection, and follow-up of LSTs. This may provide guiding principles for the global management of these lesions and standardize current practices.

Cold versus hot snare endoscopic mucosal resection for large (≥15 mm) flat non-pedunculated colorectal polyps: a randomised controlled trial

BACKGROUND AND AIMS

Conventional hot snare endoscopic mucosal resection (H-EMR) is effective for the management of large (≥20 mm) non-pedunculated colon polyps (LNPCPs) however, electrocautery-related complications may incur significant morbidity. With a superior safety profile, cold snare EMR (C-EMR) of LNPCPs is an attractive alternative however evidence is lacking. We conducted a randomised trial to compare the efficacy and safety of C-EMR to H-EMR.

METHODS

Flat, 15-50 mm adenomatous LNPCPs were prospectively enrolled and randomly assigned to C-EMR or H-EMR with margin thermal ablation at a single tertiary centre. The primary outcome was endoscopically visible and/or histologically confirmed recurrence at 6 months surveillance colonoscopy. Secondary outcomes were clinically significant post-EMR bleeding (CSPEB), delayed perforation and technical success.

RESULTS

177 LNPCPs in 177 patients were randomised to C-EMR arm (n=87) or H-EMR (n=90). Treatment groups were equivalent for technical success 86/87 (98.9%) C-EMR versus H-EMR 90/90 (100%); p=0.31. Recurrence was significantly greater in C-EMR (16/87, 18.4% vs 1/90, 1.1%; relative risk (RR) 16.6, 95% CI 2.24 to 122; p<0.001).Delayed perforation (1/90 (1.1%) vs 0; p=0.32) only occurred in the H-EMR group. CSPEB was significantly greater in the H-EMR arm (7/90 (7.8%) vs 1/87 (1.1%); RR 6.77, 95% CI 0.85 to 53.9; p=0.034).

CONCLUSION

Compared with H-EMR, C-EMR for flat, adenomatous LNPCPs, demonstrates superior safety with equivalent technical success. However, endoscopic recurrence is significantly greater for cold snare resection and is currently a limitation of the technique.

TRIAL REGISTRATION NUMBER

NCT04138030.

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

BACKGROUND AND AIMS

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

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.

Selection of endoscopic resection technique for large colorectal lesion treatment

PURPOSE OF REVIEW

Large nonpedunculated colorectal polyps ≥ 20 mm (LNPCPs) comprise 1% of all colorectal lesions. LNPCPs are more likely to contain advanced histology such as high-grade dysplasia and submucosal invasive cancer (SMIC). Endoscopic resection is the first-line approach for management of these lesions. Endoscopic resection options include endoscopic mucosal resection (EMR), cold-snare EMR (EMR), endoscopic submucosal dissection (ESD) and endoscopic full-thickness resection (EFTR). This review aimed to critically evaluate current endoscopic resection techniques.

RECENT FINDINGS

Evidence-based selective resection algorithms should inform the most appropriate endoscopic resection technique. Most LNPCPs are removed by conventional EMR but there has been a trend toward C-EMR for endoscopic resection of LNPCPs. More high-quality trials are required to better define the limitations of C-EMR. Advances in our understanding of ESD technique, has clarified its role within the colorectum. More recently, the development of a full thickness resection device (FTRD) has allowed the curative endoscopic resection of select lesions.

SUMMARY

Endoscopic resection should be regarded as the principle approach for all LNPCPs. Underpinned by high-quality research, endoscopic resection has become more nuanced, leading to improved patient outcomes.

Cold Endoscopic Mucosal Resection (c-EMR) of Nonpedunculated Colorectal Polyps ≥20 mm: A Systematic Review and Meta-analysis

BACKGROUND

There is increasing evidence that cold endoscopic mucosal resection (c-EMR) can effectively treat large colorectal polyps. We aim to appraise the current literature and evaluate outcomes following c-EMR for nonpedunculated colonic polyps ≥20 mm.

METHODS

Major databases were searched. Primary outcomes included recurrence rate and adverse events. Meta-analysis was performed using a random-effects model.

RESULTS

Nine articles were included in the final analysis, which included 817 patients and 1077 colorectal polyps. Average polyp size was 28.8 (±5.1) mm. The pooled recurrence rate of polyps of any histology at 4 to 6 months was 21.0% (95% CI: 9.0%-32.0%, P <0.001, I2 =97.3, P <0.001). Subgroup analysis showed that recurrence was 10% for proximal lesions (95% CI: 0.0%-20.0%, P =0.054, I2 =93.7%, P =0.054) and 9% for distal lesions (95% CI: 2.0%-21.0%, P =0.114, I2 =95.8%, P =0.114). Furthermore, subgroup analysis showed that recurrence was 12% for adenoma (95% CI: 4.0%-19.0%, P =0.003, I2 =98.0%, P =0.003), and 3% for sessile serrated polyps (95% CI: 1.0%-5.0%, P =0.002, I2 =34.4%, P =0.002). Post-polypectomy bleeding occurred in 1% (n=8/817) of patients, whereas abdominal pain occurred in 0.2% (n=2/817) of patients.

CONCLUSIONS

C-EMR for nonpedunculated colorectal polyps ≥20 mm shows an excellent safety profile with a very low rate of delayed bleeding as well as significantly less recurrence for sessile serrated polyps than adenomas.

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.

Colorectal polypectomy and endoscopic mucosal resection: European Society of Gastrointestinal Endoscopy (ESGE) Guideline - Update 2024

1:  ESGE recommends cold snare polypectomy (CSP), to include a clear margin of normal tissue (1-2 mm) surrounding the polyp, for the removal of diminutive polyps (≤ 5 mm).Strong recommendation, high quality of evidence. 2:  ESGE recommends against the use of cold biopsy forceps excision because of its high rate of incomplete resection.Strong recommendation, moderate quality of evidence. 3:  ESGE recommends CSP, to include a clear margin of normal tissue (1-2 mm) surrounding the polyp, for the removal of small polyps (6-9 mm).Strong recommendation, high quality of evidence. 4:  ESGE recommends hot snare polypectomy for the removal of nonpedunculated adenomatous polyps of 10-19 mm in size.Strong recommendation, high quality of evidence. 5:  ESGE recommends conventional (diathermy-based) endoscopic mucosal resection (EMR) for large (≥ 20 mm) nonpedunculated adenomatous polyps (LNPCPs).Strong recommendation, high quality of evidence. 6:  ESGE suggests that underwater EMR can be considered an alternative to conventional hot EMR for the treatment of adenomatous LNPCPs.Weak recommendation, moderate quality of evidence. 7:  Endoscopic submucosal dissection (ESD) may also be suggested as an alternative for removal of LNPCPs of ≥ 20 mm in selected cases and in high-volume centers.Weak recommendation, low quality evidence. 8:  ESGE recommends that, after piecemeal EMR of LNPCPs by hot snare, the resection margins should be treated by thermal ablation using snare-tip soft coagulation to prevent adenoma recurrence.Strong recommendation, high quality of evidence. 9:  ESGE recommends (piecemeal) cold snare polypectomy or cold EMR for SSLs of all sizes without suspected dysplasia.Strong recommendation, moderate quality of evidence. 10:  ESGE recommends prophylactic endoscopic clip closure of the mucosal defect after EMR of LNPCPs in the right colon to reduce to reduce the risk of delayed bleeding.Strong recommendation, high quality of evidence. 11:  ESGE recommends that en bloc resection techniques, such as en bloc EMR, ESD, endoscopic intermuscular dissection, endoscopic full-thickness resection, or surgery should be the techniques of choice in cases with suspected superficial invasive carcinoma, which otherwise cannot be removed en bloc by standard polypectomy or EMR.Strong recommendation, moderate quality of evidence.

Organ and function preservation in gastrointestinal cancer: Current and future perspectives on endoscopic ablation

The escalating prevalence of gastrointestinal cancers underscores the urgency for transformative approaches. Current treatment costs amount to billions of dollars annually, combined with the risks and comorbidities associated with invasive surgery. This highlights the importance of less invasive alternatives with organ preservation being a central aspect of the treatment paradigm. The current standard of care typically involves neoadjuvant systemic therapy followed by surgical resection. There is a growing interest in organ preservation approaches by way of minimizing extensive surgical resections. Endoscopic ablation has proven to be useful in precursor lesions, as well as in palliative cases of unresectable disease. More recently, there has been an increase in reports on the utility of adjunct endoscopic ablative techniques for downstaging disease as well as contributing to non-surgical complete clinical response. This expansive field within endoscopic oncology holds great potential for advancing patient care. By addressing challenges, fostering collaboration, and embracing technological advancements, the gastrointestinal cancer treatment paradigm can shift towards a more sustainable and patient-centric future emphasizing organ and function preservation. This editorial examines the evolving landscape of endoscopic ablation strategies, emphasizing their potential to improve patient outcomes. We briefly review current applications of endoscopic ablation in the esophagus, stomach, duodenum, pancreas, bile ducts, and colon.

Technical Advances in Endoscopic Resection Techniques for Lower GI Malignancies

Background

The management of bulky neoplastic lesions in the digestive tract has historically been a surgical pursuit. With advancements in endoscopic techniques, particularly endoscopic mucosal resection (EMR) and endoscopic submucosal dissection (ESD), a paradigm shift toward organ preservation has been initiated. These endoscopic methods, developed incrementally since the 1980s, have progressively enabled curative management of lesions with minimal morbidity, challenging the previously unchallenged domain of surgery.

Summary

This review traces the evolution of endoscopic resection from snare polypectomy and EMR to sophisticated ESD, highlighting the technological innovations that have expanded the scope of endoscopic resection. It discusses the intricacies of various EMR techniques like underwater EMR, anchoring EMR, and hybrid EMR, alongside traction-assisted methods and the use of viscous solutions for submucosal injection. Additionally, the manuscript delves into the advancements in ESD, emphasizing traction strategies, knife technology, and the optimization of endoscopes. The benefits of these advancements are weighed against the challenges in anatomopathological interpretation posed by piecemeal resections.

Key Messages

The continuous amelioration of endoscopic resection techniques has significantly improved the outcomes of digestive tract lesion management, particularly in achieving R0 resections and reducing recurrence rates. These advancements represent a monumental step toward minimizing the invasiveness of lesion management. However, despite the progress, the necessity for early follow-up post-EMR remains due to the non-negligible recurrence rates, underscoring the need for a rigorous postoperative surveillance regimen. Furthermore, our review suggests that while ESD has transformed the therapeutic landscape, its widespread adoption hinges on further simplification, safety enhancement, and acceleration of the procedure, possibly through innovations like adaptive traction devices.

Standardised training for endoscopic mucosal resection of large non-pedunculated colorectal polyps to reduce recurrence (*STAR-LNPCP study): a multicentre cluster randomised trial

OBJECTIVE

Endoscopic mucosal resection (EMR) is the preferred treatment for non-invasive large (≥20 mm) non-pedunculated colorectal polyps (LNPCPs) but is associated with an early recurrence rate of up to 30%. We evaluated whether standardised EMR training could reduce recurrence rates in Dutch community hospitals.

DESIGN

In this multicentre cluster randomised trial, 59 endoscopists from 30 hospitals were randomly assigned to the intervention group (e-learning and 2-day training including hands-on session) or control group. From April 2019 to August 2021, all consecutive EMR-treated LNPCPs were included. Primary endpoint was recurrence rate after 6 months.

RESULTS

A total of 1412 LNPCPs were included; 699 in the intervention group and 713 in the control group (median size 30 mm vs 30 mm, 45% vs 52% size, morphology, site and access (SMSA) score IV, 64% vs 64% proximal location). Recurrence rates were lower in the intervention group compared with controls (13% vs 25%, OR 0.43; 95% CI 0.23 to 0.78; p=0.005) with similar complication rates (8% vs 9%, OR 0.93; 95% CI 0.64 to 1.36; p=0.720). Recurrences were more often unifocal in the intervention group (92% vs 76%; p=0.006). In sensitivity analysis, the benefit of the intervention on recurrence rate was only observed in the 20-40 mm LNPCPs (5% vs 20% in 20-29 mm, p=0.001; 10% vs 21% in 30-39 mm, p=0.013) but less evident in ≥40 mm LNPCPs (24% vs 31%; p=0.151). In a post hoc analysis, the training effect was maintained in the study group, while in the control group the recurrence rate remained high.

CONCLUSION

A compact standardised EMR training for LNPCPs significantly reduced recurrences in community hospitals. This strongly argues for a national dedicated training programme for endoscopists performing EMR of ≥20 mm LNPCPs. Interestingly, in sensitivity analysis, this benefit was limited for LNPCPs ≥40 mm.

TRIAL REGISTRATION NUMBER

NTR7477.

Geometry of cold snare polypectomy and risk of incomplete resection

BACKGROUND

Cold snare polypectomy (CSP) is safer than and equally efficacious as hot snare polypectomy (HSP) for the removal of small (<10mm) colorectal polyps. The maximum polyp size that can be effectively managed by piecemeal CSP (p-CSP) without an excessive burden of recurrence is unknown.

METHODS

Resection error risks (RERs), defined as the estimated likelihood of incomplete removal of adenomatous tissue for a single snare resection pass, for CSP and HSP were calculated, based on an incomplete resection rate. Polyp area, snare size, estimated number of resections, and optimal resection defect area were modeled. Overall risk of incomplete resection (RIR) was defined as RIR=1 - (1 - p)n, where p is the RER and n the number of resections.

RESULTS

A 40-mm polyp has a four times greater area than a 20-mm polyp (314.16mm2 vs. 1256.64mm2), and requires three times more resections (11 vs. 33, respectively, assuming 8-mm piecemeal resection pieces for p-CSP). RIRs for a 40-mm polyp by HSP and p-CSP were 15.1%-23% and 40.74%-60.60% respectively.

CONCLUSION

RER is more important with p-CSP than with HSP. The number of resections, n, and consequently RIR increases with increasing polyp size. Given the overwhelming safety of CSP, specific techniques to minimize the RER should be studied and developed.

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.

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.).

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.

Endoscopic resection of large anastomotic polyps is safe and effective

BACKGROUND

Large (≥20mm) adenomatous anastomotic polyps (LAAPs) are uncommon. Data pertaining to their prevalence, characteristics, and the efficacy of endoscopic resection (ER) are absent. A safe and effective strategy for ER would reduce morbidity and healthcare costs.

METHODS

Large nonpedunculated colorectal polyps of ≥20mm (LNPCPs) referred for ER were prospectively studied. Multiple data points were recorded including anastomotic location, polyp morphology, resection modality, complications, and technical success.

RESULTS

Over 7 years until November 2022, 2629 lesions were referred. Of these, 10 (0.4%) were LAAPs (median size 35 mm [interquartile range (IQR) 30-40mm]). All LAAPs were removed by piecemeal endoscopic mucosal resection (EMR), most (n=9; 90%) in combination with cold-forceps avulsion with adjuvant snare-tip soft coagulation (CAST). On comparison of the LAAP group with the conventional LNPCP group, CAST was more commonly used (90% vs. 9%; P<0.001) and deep mural injury (DMI) type II was more frequent (40% vs. 11%, P=0.003); however, significant DMI (III-V) did not occur. At 6 month (IQR 5.25-6 months) surveillance, there was no recurrence in any of the 10 cases. There were no serious adverse events.

CONCLUSIONS

LAAPs present unique challenges owing to their location overlying an anastomosis. Despite these challenges they can be safely and effectively managed endoscopically without recurrence at endoscopic follow-up.

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.

A novel tool for case selection in endoscopic mucosal resection training

BACKGROUND

 As endoscopic mucosal resection (EMR) of large (≥ 20 mm) adenomatous nonpedunculated colonic polyps (LNPCPs) becomes widely practiced outside expert centers, appropriate training is necessary to avoid failed resection and inappropriate surgical referral. No EMR-specific tool guides case selection for endoscopists learning EMR. This study aimed to develop an EMR case selection score (EMR-CSS) to identify potentially challenging lesions for "EMR-naïve" endoscopists developing competency.

METHODS

 Consecutive EMRs were recruited from a single center over 130 months. Lesion characteristics, intraprocedural data, and adverse events were recorded. Challenging lesions with intraprocedural bleeding (IPB), intraprocedural perforation (IPP), or unsuccessful resection were identified and predictive variables identified. Significant variables were used to form a numerical score and receiver operating characteristic curves were used to generate cutoff values.

RESULTS

 Of 1993 LNPCPs, 286 (14.4 %) were in challenging locations (anorectal junction, ileocecal valve, or appendiceal orifice), 368 (18.5 %) procedures were complicated by IPB and 77 (3.9 %) by IPP; 110 (5.5 %) procedures were unsuccessful. The composite end point of IPB, IPP, or unsuccessful EMR was present in 526 cases (26.4 %). Lesion size, challenging location, and sessile morphology were predictive of the composite outcome. A six-point score was generated with a cutoff value of 2 demonstrating 81 % sensitivity across the training and validation cohorts.

CONCLUSIONS

 The EMR-CSS is a novel case selection tool for conventional EMR training, which identifies a subset of adenomatous LNPCPs that can be successfully and safely attempted in early EMR training.

Endoscopic resection-related colorectal strictures: risk factors, management, and long-term outcomes

INTRODUCTION

Colorectal strictures related to endoscopic resection (ER) of large nonpedunculated colorectal polyps (LNPCPs) may be problematic. Data on prevalence, risk factors, and management are limited. We report a prospective study of colorectal strictures following ER and describe our approach to management.

METHODS

We analyzed prospectively collected data over 150 months, until June 2021, for patients who underwent ER for LNPCPs ≥ 40 mm. The ER defect size was graded as < 60 %, 60 %-89 %, or ≥ 90 % of the luminal circumference. Strictures were considered "severe" if patients experienced obstructive symptoms, "moderate" if an adult colonoscope could not pass the stenosis, or "mild" if there was resistance on successful passage. Primary outcomes included stricture prevalence, risk factors, and management.

RESULTS

916 LNPCPs ≥ 40 mm in 916 patients were included (median age 69 years, interquartile range 61-76 years, male sex 484 [52.8 %]). The primary resection modality was endoscopic mucosal resection in 859 (93.8 %). Risk of stricture formation with an ER defect ≥ 90 %, 60 %-89 %, and < 60 % was 74.2 % (23/31), 25.0 % (22/88), and 0.8 % (6 /797), respectively. Severe strictures only occurred with ER defects ≥ 90 % (22.6 %, 7/31). Defects < 60 % conferred low risk of only mild strictures (0.8 %, 6/797). Severe strictures required earlier (median 0.9 vs. 4.9 months; P = 0.01) and more frequent (median 3 vs. 2; P = 0.02) balloon dilations than moderate strictures.

CONCLUSION

Most patients with ER defects ≥ 90 % of luminal circumference developed strictures, many of which were severe and required early balloon dilation. There was minimal risk with ER defects < 60 %.

Recurrence and survival in dogs with excised colorectal polyps: A retrospective study of 58 cases

BACKGROUND

Compared to humans, colorectal polyps are relatively rare in dogs. Epidemiological and prognostic data remain accordingly sparse, although they could help veterinary clinicians in the management of these cases.

OBJECTIVES

To report the epidemiological data of dogs with colorectal polyps and identify factors associated with recurrence and survival.

ANIMALS

Fifty-eight client-owned dogs with colorectal polyps admitted to 7 veterinary hospitals (53 dogs from France, 5 dogs from Spain, and 4 dogs from Portugal) were included.

METHODS

Retrospective multicentric cohort study. Medical records and long-term outcome of the dogs were reviewed. When available, histological samples were reassessed by 2 board-certified pathologists according to the revised Vienna classification (RVC).

RESULTS

The West Highland White Terrier (WHWT) breed was significantly associated with the presence of colorectal polyps (OR: 20; 95% CI: 7.5-52; P < .001). The overall median time to recurrence was not reached after 2000 days. The overall estimated median survival time was 1640 days. WHWT breed and larger polyps were significantly associated with a shorter time of polyp recurrence after surgical removal (respectively, P = .05 and P = .01).

CONCLUSIONS AND CLINICAL IMPORTANCE

The probability of recurrence of colorectal polyps in dogs is low, but increased in WHWTs and larger polyps, which might benefit from routine screening after removal. No effective predictors of polyp recurrence and survival were identified using the RVC.

Treatment of adenoma recurrence after endoscopic mucosal resection

OBJECTIVE

Residual or recurrent adenoma (RRA) after endoscopic mucosal resection (EMR) of large non-pedunculated colorectal polyps (LNPCPs) of ≥20 mm is a major limitation. Data on outcomes of the endoscopic treatment of recurrence are scarce, and no evidence-based standard exists. We investigated the efficacy of endoscopic retreatment over time in a large prospective cohort.

DESIGN

Over 139 months, detailed morphological and histological data on consecutive RRA detected after EMR for single LNPCPs at one tertiary endoscopy centre were prospectively recorded during structured surveillance colonoscopy. Endoscopic retreatment was performed on cases with evidence of RRA and was performed predominantly using hot snare resection, cold avulsion forceps with adjuvant snare tip soft coagulation or a combination of the two.

RESULTS

213 (14.6%) patients had RRA (168 (78.9%) at first surveillance and 45 (21.1%) thereafter). RRA was commonly 2.5-5.0 mm (48.0%) and unifocal (78.7%). Of 202 (94.8%) cases which had macroscopic evidence of RRA, 194 (96.0%) underwent successful endoscopic therapy and 161 (83.4%) had a subsequent follow-up colonoscopy. Of the latter, endoscopic therapy of recurrence was successful in 149 (92.5%) of 161 in the per-protocol analysis, and 149 (73.8%) of 202 in the intention-to-treat analysis, with a mean of 1.15 (SD 0.36) retreatment sessions. No adverse events were directly attributable to endoscopic therapy. Further RRA after endoscopic therapy was endoscopically treatable in most cases. Overall, only 9 (4.2%, 95% CI 2.2% to 7.8%) of 213 patients with RRA required surgery.Thus 159 (98.8%, 95% CI 95.1% to 99.8%) of 161 cases with initially successful endoscopic treatment of RRA and follow-up remained surgery-free for a median of 13 months (IQR 25.0) of follow-up.

CONCLUSIONS

RRA after EMR of LNPCPs can be effectively treated using simple endoscopic techniques with long-term adenoma remission of >90%; only 16% required retreatment. Therefore, more technically complex, morbid and resource-intensive endoscopic or surgical techniques are required only in selected cases.

TRIAL REGISTRATION NUMBERS

NCT01368289 and NCT02000141.

The Surface Morphology of Large Nonpedunculated Colonic Polyps Predicts Synchronous Large Lesions

BACKGROUND & AIMS

Large (≥20 mm) nonpedunculated colorectal polyps (LNPCPs) may have synchronous LNPCPs in up to 18% of cases. The nature of this relationship has not been investigated. We aimed to examine the relationship between individual LNPCP characteristics and synchronous colonic LNPCPs.

METHODS

Consecutive patients referred for resection of LNPCPs over 130 months until March 2022 were enrolled. Serrated lesions and mixed granularity LNPCPs were excluded from analysis. Patients with multiple LNPCPs resected were identified, and the largest was labelled as dominant. The primary outcome was the identification of individual lesion characteristics associated with the presence of synchronous LNPCPs.

RESULTS

There were 3149 of 3381 patients (93.1%) who had a single LNPCP. In 232 (6.9%) a synchronous lesion was detected. Solitary lesions had a median size of 35 mm with a predominant Paris 0-IIa morphology (42.9%) and right colon location (59.5%). In patients with ≥2 LNPCPs, the dominant lesion had a median size of 40 mm, Paris 0-IIa (47.6%) morphology, and right colon location (65.9%). In this group, 35.8% of dominant LNPCPs were non-granular compared with 18.7% in the solitary LNPCP cohort. Non-granular (NG)-LNPCPs were more likely to demonstrate synchronous disease, with left colon NG-LNPCPs demonstrating greater risk (odds ratio, 4.78; 95% confidence interval, 2.95-7.73) than right colon NG-LNPCPs (odds ratio, 1.99; 95% confidence interval, 1.39-2.86).

CONCLUSIONS

We found that 6.9% of LNPCPs have synchronous disease, with NG-LNPCPs demonstrating a greater than 4-fold increased risk. With post-colonoscopy interval cancers exceeding 5%, endoscopists must be cognizant of an individual's LNPCP phenotype when examining the colon at both index procedure and surveillance.

CLINICALTRIALS

gov, NCT01368289; NCT02000141; NCT02198729.

Endoscopic Management of Large Non-Pedunculated Colorectal Polyps

Large non-pedunculated colorectal polyps ≥20 mm (LNPCPs) comprise approximately 1% of all colorectal polyps. LNPCPs more commonly contain high-grade dysplasia, covert and overt cancer. These lesions can be resected using several means, including conventional endoscopic mucosal resection (EMR), cold-snare EMR (C-EMR) and endoscopic submucosal dissection (ESD). This review aimed to provide a comprehensive, critical and objective analysis of ER techniques. Evidence-based, selective resection algorithms should be used when choosing the most appropriate technique to ensure the safe and effective removal of LNPCPs. Due to its enhanced safety and comparable efficacy, there has been a paradigm shift towards cold-snare polypectomy (CSP) for the removal of small polyps (<10 mm). This technique is now being applied to the management of LNPCPs; however, further research is required to define the optimal LNPCP subtypes to target and the viable upper size limit. Adjuvant techniques, such as thermal ablation of the resection margin, significantly reduce recurrence risk. Bleeding risk can be mitigated using through-the-scope clips to close defects in the right colon. Endoscopic surveillance is important to detect recurrence and synchronous lesions. Recurrence can be readily managed using an endoscopic approach.

[Interventional endoscopy in gastroenterology]

Essential innovations in interventional endoscopy have significantly broadened the treatment armamentarium in gastroenterology. The treatment and complication management of intraepithelial neoplasms and early forms of cancer are increasingly being primarily addressed endoscopically. In cases of endoluminal lesions with no risk of lymph node or distant metastases, endoscopic mucosal resection and endoscopic submucosal dissection have become established as standards. For broad-based adenomas, coagulation of the resection margins should be performed in the case of a piecemeal resection. Submucosal lesions can be reached and resected by tunneling techniques. Peroral endoscopic myotomy in cases of achalasia is a new treatment option for hypertensive and hypercontractile motility disorders. In addition, endoscopic myotomy for gastroparesis has shown very promising results. In this article, new resection techniques and so-called third space endoscopy are presented and critically discussed.

Can white-light endoscopy or narrow-band imaging avoid biopsy of colorectal endoscopic mucosal resection scars? A multicenter randomized single-blind crossover trial

BACKGROUND : Current guidelines suggest that routine biopsy of post-endoscopic mucosal resection (EMR) scars can be abandoned, provided that a standardized imaging protocol with virtual chromoendoscopy is used. However, few studies have examined the accuracy of advanced endoscopic imaging, such as narrow-band imaging (NBI) vs. white-light endoscopy (WLE) for prediction of histological recurrence. We aimed to assess whether NBI accuracy is superior to that of WLE and whether one or both techniques can replace biopsies. METHODS : The study was a multicenter, randomized, pathologist-blind, crossover trial, with consecutive patients undergoing first colonoscopy after EMR of lesions ≥ 20 mm. Computer-generated randomization and opaque envelope concealed allocation. Patients were randomly assigned to scar examination with NBI followed by WLE (NBI + WLE), or WLE followed by NBI (WLE + NBI). Histology was the reference method, with biopsies being performed for all tissues. RESULTS : The study included 203 scars (103 in the NBI + WLE group, 100 in the WLE + NBI group). Recurrence was confirmed histologically in 29.6 % of the scars. The diagnostic accuracy of NBI was not statistically different from that of WLE (95 % [95 %CI 92 %-98 %] vs. 94 % [95 %CI 90 %-97 %]; P = 0.48). The negative predictive values (NPVs) were 96 % (95 %CI 93 %-99 %) for NBI and 93 % (95 %CI 89 %-97 %) for WLE (P = 0.06). CONCLUSIONS : The accuracy of NBI for the diagnosis of recurrence was not superior to that of WLE. Endoscopic assessment of EMR scars with WLE and NBI achieved an NPV that would allow routine biopsy to be avoided in cases of negative optical diagnosis.

Curriculum for training in endoscopic mucosal resection in the colon: European Society of Gastrointestinal Endoscopy (ESGE) Position Statement

Endoscopic mucosal resection (EMR) is the standard of care for the complete removal of large (≥ 10 mm) nonpedunculated colorectal polyps (LNPCPs). Increased detection of LNPCPs owing to screening colonoscopy, plus high observed rates of incomplete resection and need for surgery call for a standardized approach to training in EMR. 1 : Trainees in EMR should have achieved basic competence in diagnostic colonoscopy, < 10-mm polypectomy, pedunculated polypectomy, and common methods of gastrointestinal endoscopic hemostasis. The role of formal training courses is emphasized. Training may then commence in vivo under the direct supervision of a trainer. 2 : Endoscopy units training endoscopists in EMR should have specific processes in place to support and facilitate training. 3: A trained EMR practitioner should have mastered theoretical knowledge including how to assess an LNPCP for risk of submucosal invasion, how to interpret the potential difficulty of a particular EMR procedure, how to decide whether to remove a particular LNPCP en bloc or piecemeal, whether the risks of electrosurgical energy can be avoided for a particular LNPCP, the different devices required for EMR, management of adverse events, and interpretation of reports provided by histopathologists. 4: Trained EMR practitioners should be familiar with the patient consent process for EMR. 5: The development of endoscopic non-technical skills (ENTS) and team interaction are important for trainees in EMR. 6: Differences in recommended technique exist between EMR performed with and without electrosurgical energy. Common to both is a standardized technique based upon dynamic injection, controlled and precise snare placement, safety checks prior to the application of tissue transection (cold snare) or electrosurgical energy (hot snare), and interpretation of the post-EMR resection defect. 7: A trained EMR practitioner must be able to manage adverse events associated with EMR including intraprocedural bleeding and perforation, and post-procedural bleeding. Delayed perforation should be avoided by correct interpretation of the post-EMR defect and treatment of deep mural injury. 8: A trained EMR practitioner must be able to communicate EMR procedural findings to patients and provide them with a plan in case of adverse events after discharge and a follow-up plan. 9: A trained EMR practitioner must be able to detect and interrogate a post-endoscopic resection scar for residual or recurrent adenoma and apply treatment if necessary. 10: Prior to independent practice, a minimum of 30 EMR procedures should be performed, culminating in a trainer-guided assessment of competency using a validated assessment tool, taking account of procedural difficulty (e. g. using the SMSA polyp score). 11: Trained practitioners should log their key performance indicators (KPIs) of polypectomy during independent practice. A guide for target KPIs is provided in this document.