How to Perform High-Quality Endoscopic Mucosal Resection During Colonoscopy

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.

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.).

A simplified algorithm to evaluate the risk of submucosal invasive cancer in large (≥20 mm) nonpedunculated colonic polyps

BACKGROUND

Recognition of submucosal invasive cancer (SMIC) in large (≥20 mm) nonpedunculated colonic polyps (LNPCPs) informs selection of the optimal resection strategy. LNPCP location, morphology, and size influence the risk of SMIC; however, currently no meaningful application of this information has simplified the process to make it accessible and broadly applicable. We developed a decision-making algorithm to simplify the identification of LNPCP subtypes with increased risk of potential SMIC.

METHODS

Patients referred for LNPCP resection from September 2008 to November 2022 were enrolled. LNPCPs with SMIC were identified from endoscopic resection specimens, lesion biopsies, or surgical outcomes. Decision tree analysis of lesion characteristics identified in multivariable analysis was used to create a hierarchical classification of SMIC prevalence.

RESULTS

2451 LNPCPs were analyzed: 1289 (52.6%) were flat, 1043 (42.6%) nodular, and 118 (4.8%) depressed. SMIC was confirmed in 273 of the LNPCPs (11.1%). It was associated with depressed and nodular vs. flat morphology (odds ratios [ORs] 35.7 [95%CI 22.6-56.5] and 3.5 [95%CI 2.6-4.9], respectively; P<0.001); rectosigmoid vs. proximal location (OR 3.2 [95%CI 2.5-4.1]; P<0.001); nongranular vs. granular appearance (OR 2.4 [95%CI 1.9-3.1]; P<0.001); and size (OR 1.12 per 10-mm increase [95%CI 1.05-1.19]; P<0.001). Decision tree analysis targeting SMIC identified eight terminal nodes: SMIC prevalence was 62% in depressed LNPCPs, 19% in nodular rectosigmoid LNPCPs, and 20% in nodular proximal colon nongranular LNPCPs.

CONCLUSIONS

This decision-making algorithm simplifies identification of LNPCPs with an increased risk of potential SMIC. When combined with surface optical evaluation, it facilitates accurate lesion characterization and resection choices.

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.

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

BACKGROUND

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

OBJECTIVE

To compare ESD and EMR for large colonic adenomas.

DESIGN

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

SETTING

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

PARTICIPANTS

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

INTERVENTION

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

MEASUREMENTS

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

RESULTS

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

LIMITATION

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

CONCLUSION

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

PRIMARY FUNDING SOURCE

French Ministry of Health.

Safety and efficacy of physician-administered balanced-sedation for the endoscopic mucosal resection of large non-pedunculated colorectal polyps

Background and study aims Because of concerns about peri-procedural adverse events (AEs), guidelines recommend anesthetist-managed sedation (AMS) for long and complex endoscopic procedures. The safety and efficacy of physician-administered balanced sedation (PA-BS) for endoscopic mucosal resection (EMR) of large non-pedunculated colorectal polyps (LNPCPs) ≥20 mm is unknown. Patients and methods We compared PA-BS with AMS in a retrospective study of prospectively collected data from consecutive patients referred for management of LNPCPs (NCT01368289; NCT02000141). A per-patient propensity analysis was performed following a 1:2 nearest-neighbor (Greedy-type) match, based on age, gender, Charlson comorbidity index, and lesion size. The primary outcome was any peri-procedural AE, which included hypotension, hypertension, tachycardia, bradycardia, hypoxia, and new arrhythmia. Secondary outcomes were unplanned admissions, 28-day re-presentation, technical success, and recurrence. Results Between January 2016 and June 2020, 700 patients underwent EMR for LNPCPs, of whom 638 received PA-BS. Among them, the median age was 70 years (interquartile range [IQR] 62-76 years), size 35 mm (IQR 25-45 mm), and duration 35 minutes (IQR 25-60 minutes). Peri-procedural AEs occurred in 149 (23.4%), most commonly bradycardia (116; 18.2%). Only five (0.8%) required an unplanned sedation-related admission due to AEs (2 hypotension, 1 arrhythmia, 1 bradycardia, 1 hypoxia), with a median inpatient stay of 1 day (IQR 1-3 days). After propensity-score matching, there were no differences between PA-BS and AMS in peri-procedural AEs, unplanned admissions, 28-day re-presentation rates, technical success or recurrence. Conclusions Physician-administered balanced sedation for the EMR of LNPCPs is safe. Peri-procedural AEs are infrequent, transient, rarely require admission (<1%), and are experienced in similar frequencies to those receiving anesthetist-managed sedation.

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 %.

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.

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.

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.

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.

A Rectum-Specific Selective Resection Algorithm Optimizes Oncologic Outcomes for Large Nonpedunculated Rectal Polyps

BACKGROUND AND AIMS

Endoscopic mucosal resection (EMR) and endoscopic submucosal dissection (ESD) are complementary techniques for large (≥20 mm) nonpedunculated rectal polyps (LNPRPs). A mechanism for appropriate technique selection has not been described.

METHODS

We evaluated the performance of a selective resection algorithm (SRA) (August 2017 to April 2021) compared with a universal EMR algorithm (UEA) (July 2008 to July 2017) for LNPRPs within a prospective observational study. In the SRA, LNPRPs with features of superficial submucosal invasive cancer (SMIC) (<1000 μm; Kudo pit pattern Vi), or with an increased risk of SMIC (Paris 0-Is or 0-IIa+Is nongranular, 0-IIa+Is granular with a dominant nodule ≥10 mm) underwent ESD. The remaining LNPRPs underwent EMR. Algorithm performance was evaluated by SMIC identified after EMR, curative oncologic resection (R0 resection, superficial SMIC, absence of negative histologic features), technical success, adverse events, and recurrence at first surveillance colonoscopy.

RESULTS

A total of 480 LNPRPs were evaluated (290 UEA, 190 SRA). Median lesion size was 40 (interquartile range, 30-60) mm. SMIC was identified in 56 (11.7%) LNPRPs. Significant differences in SMIC after EMR (SRA 1 [1.0%] vs UEA 35 [12.1%]; P = .001) and curative oncologic resection (SRA n = 7 [33.3%] vs UEA n = 2 [5.7%]; P = .010) were identified. No significant differences in technical success or adverse events were identified (all P > .137). Among LNPRPs with SMIC amenable to curative oncologic resection and which underwent ESD, 100% (n = 7 of 7) were cured.

CONCLUSIONS

A rectum-specific SRA optimizes oncologic outcomes for LNPRPs and mitigates the risk of piecemeal resection of cancers.

Performance measures for the SACRED team-centered approach to advanced gastrointestinal endoscopy: European Society of Gastrointestinal Endoscopy (ESGE) Quality Improvement Initiative

The European Society of Gastrointestinal Endoscopy and United European Gastroenterology have defined performance measures for upper and lower gastrointestinal, pancreaticobiliary, and small-bowel endoscopy. Quality indicators to guide endoscopists in the growing field of advanced endoscopy are also underway. We propose that equal attention is given to developing the entire advanced endoscopy team and not the individual endoscopist alone.We suggest that the practice of teams intending to deliver high quality advanced endoscopy is underpinned by six crucial principles concerning: selection, acceptance, complications, reconnaissance, envelopment, and documentation (SACRED).

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.

Efficacy and safety of endoscopic resection techniques of large colorectal lesions: experience of a referral center in Italy

BACKGROUND

Endoscopic mucosal resection and submucosal dissection (ESD) are treatments of choice for superficial neoplastic colorectal lesions. Only a few studies have compared these techniques.

AIM

To compare the efficacy and safety of endoscopic piecemeal mucosal resection (EPMR), ESD and hybrid-endoscopic submucosal dissection (H-ESD) of large colorectal lesions in a Western endoscopic center.

METHODS

This is a retrospective analysis on a prospective medical database of consecutive colorectal superficial lesions larger than 20 mm, resected by EPMR, ESD or H-ESD collected from 2015 to 2019.

RESULTS

Two hundred twenty-nine colorectal lesions were included. All lesions were completely endoscopically resected, 65.9% by EPMR, 19.7% by ESD and 14.4% by H-ESD. Endoscopic control after the index procedure was available for 86.5% patients. Among these patients, 80% had a second follow-up colonoscopy. The overall recurrence rate was 13.2, 0 and 6.1% for EPMR, ESD and H-ESD respectively, with a significant difference between EPMR and ESD. All recurrences were endoscopically treated during follow-up procedures. Risk of complications was not significantly different between the three groups.

CONCLUSIONS

EPMR, ESD and H-ESD are effective and safe procedures. Recurrence rate in EPMR was higher but can be managed endoscopically with high success rates. EPMR is faster and technically simpler so should be considered a potential first-line therapy for colorectal superficial neoplastic lesions.

Polypectomy for Large Polyps with Endoscopic Mucosal Resection

Beginning in 1955, when the saline injection was first described to prevent transmural injury during polyp fulguration, endoscopic mucosal resection (EMR) has grown exponentially, both in scope and in practice. Because EMR is an organ-preserving technique even for large polyps, this allows for comparable outcomes to surgery, but substantially improved cost savings and significantly reduced morbidity and mortality. To achieve this, however, one must master the 4 fundamental components that are critical to the success of EMR- time, team, tools, and technique. This article aims to provide a compendium of state of the art updates within the field of endoluminal resection.

Incremental benefit of dye-based chromoendoscopy to predict the risk of submucosal invasive cancer in large nonpedunculated colorectal polyps

BACKGROUND AND AIMS

Detailed lesion assessment of large nonpedunculated colorectal polyps (LNPCPs; ≥20 mm) can help predict the risk of submucosal invasive cancer (SMIC). Traditionally this has required the use of dye-based chromoendoscopy (DBC). We sought to assess the accuracy and incremental benefit of DBC in addition to high-definition white-light imaging (HDWLI) and virtual chromoendoscopy (VCE) for the prediction of SMIC within LNPCPs.

METHODS

A prospective observational study of consecutive LNPCPs at a single tertiary referral center was performed. Before resection all lesions were assessed for the presence of a demarcated area (DA), defined as an area of disordered pit or microvascular pattern, by 2 trained endoscopists before and after DBC. Diagnostic performance characteristics were calculated with histology as the reference criterion standard, and overall agreement was calculated using the κ statistic.

RESULTS

Over 39 months to March 2021, 400 consecutive LNPCPs (median lesion size, 35 mm; interquartile range, 25-45) were analyzed. The overall rate of SMIC was 6.5%. Presence of a DA had an accuracy of 91% (95% confidence interval, 87.7-93.5) for SMIC, independent of the use of DBC. The rate of interobserver agreement for presence of a DA using HDWLI + VCE was very high (κ = .96) with no benefit gained by the addition of DBC.

CONCLUSIONS

The use of HDWLI and VCE is likely to be adequate for lesion assessment for the prediction of SMIC among LNPCPs. Further, the absence of a DA is strongly predictive for the absence of SMIC, independent to the use of DBC. (Clinical trial registration number: NCT03506321.).

Simple optical evaluation criteria reliably identify the post-endoscopic mucosal resection scar for benign large non-pedunculated colorectal polyps without tattoo placement

BACKGROUND

Recognition of the post-endoscopic mucosal resection (EMR) scar is critical for large (≥ 20 mm) non-pedunculated colorectal polyp (LNPCP) management. The utility of intraluminal tattooing to facilitate scar identification is unknown.

METHODS

We evaluated the ability of simple easy-to-use optical evaluation criteria to detect the post-EMR scar, with or without tattoo placement, in a prospective observational cohort of LNPCPs referred for endoscopic resection. The primary outcome was scar identification, further stratified by lesion size (20-39 mm, ≥ 40 mm) and histopathology (adenomatous, serrated).

RESULTS

1023 LNPCPs underwent both successful EMR and first surveillance colonoscopy (median size 35 mm, IQR 30-50 mm); 124 (12.1 %) had an existing tattoo or a tattoo placed at the index EMR. The post-EMR scar was identified in 1020 patients (99.7 %). The presence of a tattoo did not affect scar identification (100.0 % vs. 99.7 %; P > 0.99). There was no difference for LNPCPs 20-39 mm, LNPCPs ≥ 40 mm, adenomatous LNPCPs, and serrated LNPCPs (all P > 0.99).

CONCLUSIONS

The post-EMR scar can be reliably identified with simple easy-to-use optical evaluation criteria, without the need for universal tattoo placement.

Outcomes of Deep Mural Injury After Endoscopic Resection: An International Cohort of 3717 Large Non-Pedunculated Colorectal Polyps

BACKGROUND & AIMS

Although perforation is the most feared adverse event associated with endoscopic mucosal resection (EMR), limited data exists concerning its management. Therefore, we sought to evaluate the short- and long-term outcomes of intra-procedural deep mural injury (DMI) in an international multi-center observational cohort of large (≥20 mm) non-pedunculated colorectal polyps (LNPCPs).

METHODS

Consecutive patients who underwent EMR for a LNPCP ≥20 mm were evaluated. Significant DMI (S-DMI) was defined as Sydney DMI Classification type III (muscularis propria injury, target sign) or type IV/V (perforation without or with contamination, respectively). The primary outcome was successful S-DMI defect closure. Secondary outcomes included technical success (removal of all visible polypoid tissue during index EMR), surgical referral and recurrence at first surveillance colonscopy (SC1).

RESULTS

Between July 2008 to May 2020, 3717 LNPCPs underwent EMR. Median lesion size was 35mm (interquartile range (IQR) 25 to 45mm). Significant DMI was identified in 101 cases (2.7%), with successful defect closure in 98 (97.0%) using a median of 4 through-the-scope clips (TTSCs; IQR 3 to 6 TTSCs). Three (3.0%) patients underwent S-DMI-related urgent surgery. Technical success was achieved in 94 (93.1%) patients, with 46 (45.5%) admitted to hospital (median duration 1 day; IQR 1 to 2 days). Comparing LNPCPs with and without S-DMI, no differences in technical success (94 (93.1%) vs 3316 (91.7%); P = .62) or SC1 recurrence (12 (20.0%) vs 363 (13.6%); P = .15) were identified.

CONCLUSIONS

Significant DMI is readily managed endoscopically and does not appear to affect technical success or recurrence.

Effect of prophylactic endoscopic clip placement on clinically significant post-endoscopic mucosal resection bleeding in the right colon: a single-centre, randomised controlled trial

BACKGROUND

Endoscopic mucosal resection (EMR) is a cornerstone in the management of large (≥20 mm) non-pedunculated colorectal polyps. Clinically significant post-EMR bleeding occurs in 7% of cases and is most frequently encountered in the right colon. We aimed to assess the use of prophylactic clip closure in preventing clinically significant post-EMR bleeding within the right colon.

METHODS

We conducted a randomised controlled trial at a tertiary centre in Australia. Patients referred for the EMR of large non-pedunculated colorectal polyps in the right colon were eligible. Patients were randomly assigned (1:1) into the clip or control (no clip) group, using a computerised random-number generator. The primary endpoint was clinically significant post-EMR bleeding, defined as haematochezia necessitating emergency department presentation, hospitalisation, or re-intervention within 14 days post-EMR, which was analysed on the basis of intention-to-treat principles. The trial is registered with ClinicalTrials.gov, NCT02196649, and has been completed.

FINDINGS

Between Feb 4, 2016, and Dec 15, 2020, 231 patients were randomly assigned: 118 to the clip group and 113 to the control group. In the intention-to-treat analysis, clinically significant post-EMR bleeding was less frequent in the clip group than in the control group (four [3·4%] of 118 patients vs 12 [10·6%] of 113; p=0·031; absolute risk reduction 7·2% [95% CI 0·7-13·8]; number needed to treat 13·9). There were no differences between groups in adverse events, including delayed perforation (one [<1%] in the clip group vs one [<1%] in the control group) and post-EMR pain (four [3%] vs six [5%]). No deaths were reported.

INTERPRETATION

Prophylactic clip closure can be performed following the EMR of large non-pedunculated colorectal polyps of 20 mm or larger in the right colon to reduce the risk of clinically significant post-EMR bleeding.

FUNDING

None.

Endoscopic resection outcomes and predictors of failed en bloc endoscopic mucosal resection of colorectal polyps ≤ 20 mm among advanced endoscopy trainees

Background and study aims  En bloc endoscopic mucosal resection (EMR) is preferred over piecemeal resection for polyps ≤ 20 mm. Data on colorectal EMR training are limited. We aimed to evaluate the en bloc EMR rate of polyps ≤ 20 mm among advanced endoscopy trainees and to identify predictors of failed en bloc EMR. Methods  This was a multicenter prospective study evaluating trainee performance in EMR during advanced endoscopy fellowship. A logistic regression model was used to identify the number of procedures and lesion cut-off size associated with an en bloc EMR rate of ≥ 80 %. Multivariate analysis was performed to identify predictors of failed en bloc EMR. Results  Six trainees from six centers performed 189 colorectal EMRs, of which 104 (55 %) were for polyps ≤ 20 mm. Of these, 57.7 % (60/104) were resected en bloc. Trainees with ≥ 30 EMRs (OR 6.80; 95 % CI: 2.80-16.50; P  = 0.00001) and lesions ≤ 17 mm (OR 4.56;95 CI:1.23-16.88; P  = 0.02) were more likely to be associated with an en bloc EMR rate of ≥ 80 %. Independent predictors of failed en bloc EMR on multivariate analysis included: larger polyp size (OR:6.83;95 % CI:2.55-18.4; P  = 0.0001), right colon location (OR:7.15; 95 % CI:1.31-38.9; P  = 0.02), increased procedural difficulty (OR 2.99; 95 % CI:1.13-7.91; P  = 0.03), and having performed < 30 EMRs (OR: 4.87; 95 %CI: 1.05-22.61; P  = 0.04). Conclusions  In this pilot study, we demonstrated that a relatively low proportion of trainees achieved en bloc EMR for polyps ≤ 20 mm and identified procedure volume and lesion size thresholds for successful en bloc EMR and independent predictors for failed en bloc resection. These preliminary results support the need for future efforts to define EMR procedure competence thresholds during training.

Optical Evaluation for Predicting Cancer in Large Nonpedunculated Colorectal Polyps Is Accurate for Flat Lesions

BACKGROUND AND AIMS

The ability of optical evaluation to diagnose submucosal invasive cancer (SMIC) prior to endoscopic resection of large (≥20 mm) nonpedunculated colorectal polyps (LNPCPs) is critical to inform therapeutic decisions. Prior studies suggest that it is insufficiently accurate to detect SMIC. It is unknown whether lesion morphology influences optical evaluation performance.

METHODS

LNPCPs ≥20 mm referred for endoscopic resection within a prospective, multicenter, observational cohort were evaluated. Optical evaluation was performed prior to endoscopic resection with the optical prediction of SMIC based on established features (Kudo V pit pattern, depressed morphology, rigidity/fixation, ulceration). Optical evaluation performance outcomes were calculated. Outcomes were reported by dominant morphology: nodular (Paris 0-Is/0-IIa+Is) vs flat (Paris 0-IIa/0-IIb) morphology.

RESULTS

From July 2013 to July 2019, 1583 LNPCPs (median size 35 [interquartile range, 25-50] mm; 855 flat, 728 nodular) were assessed. SMIC was identified in 146 (9.2%; 95% confidence interval [CI], 7.9%-10.8%). Overall sensitivity and specificity were 67.1% (95% CI, 59.2%-74.2%) and 95.1% (95% CI, 93.9%-96.1%), respectively. The overall SMIC miss rate was 3.0% (95% CI, 2.3%-4.0%). Significant differences in sensitivity (90.9% vs 52.7%), specificity (96.3% vs 93.7%), and SMIC miss rate (0.6% vs 5.9%) between flat and nodular LNPCPs were identified (all P < .027). Multiple logistic regression identified size ≥40 mm (odds ratio [OR], 2.0; 95% CI, 1.0-3.8), rectosigmoid location (OR, 2.0; 95% CI, 1.1-3.7), and nodular morphology (OR, 7.2; 95% CI, 2.8-18.9) as predictors of missed SMIC (all P < .039).

CONCLUSIONS

Optical evaluation performance is dependent on lesion morphology. In the absence of features suggestive of SMIC, flat lesions can be presumed benign and be managed accordingly.

Impact of technical innovations in EMR in the treatment of large nonpedunculated polyps involving the ileocecal valve (with video)

BACKGROUND AND AIMS

The endoscopic management of large nonpedunculated colorectal polyps involving the ileocecal valve (ICV-LNPCPs) remains challenging because of its unique anatomic features, with long-term outcomes inferior to LNPCPs not involving the ICV. We sought to evaluate the impact of technical innovations and advances in the EMR of ICV-LNPCPs.

METHODS

The performance of EMR for ICV-LNPCPs was retrospectively evaluated in a prospective observational cohort of LNPCPs ≥20 mm. Efficacy was measured by clinical success (removal of all polypoid tissue during index EMR and avoidance of surgery) and recurrence at first surveillance colonoscopy. Accounting for the adoption of technical innovations, comparisons were made between an historical cohort (September 2008 to April 2016) and contemporary cohort (May 2016 to October 2020). Safety was evaluated by documenting the frequencies of intraprocedural bleeding, delayed bleeding, deep mural injury, and delayed perforation.

RESULTS

Between September 2008 to October 2020, 142 ICV-LNPCPs were referred for EMR. Median ICV-LNPCP size was 35 mm (interquartile range, 25-50 mm). When comparing the contemporary (n = 66) and historical cohorts (n = 76) of ICV-LNPCPs, there were significant differences in clinical success (93.9% vs 77.6%, P = .006) and recurrence (4.6% vs 21.0%, P = .019).

CONCLUSIONS

With technical advances, ICV-LNPCPs can be effectively and safely managed by EMR, independent of lesion complexity. Most patients experience excellent outcomes and avoid surgery.

Piecemeal cold snare polypectomy versus conventional endoscopic mucosal resection for large sessile serrated lesions: a retrospective comparison across two successive periods

OBJECTIVE

Large (≥20 mm) sessile serrated lesions (L-SSL) are premalignant lesions that require endoscopic removal. Endoscopic mucosal resection (EMR) is the existing standard of care but carries some risk of adverse events including clinically significant post-EMR bleeding and deep mural injury (DMI). The respective risk-effectiveness ratio of piecemeal cold snare polypectomy (p-CSP) in L-SSL management is not fully known.

DESIGN

Consecutive patients referred for L-SSL management were treated by p-CSP from April 2016 to January 2020 or by conventional EMR in the preceding period between July 2008 and March 2016 at four Australian tertiary centres. Surveillance colonoscopies were conducted at 6 months (SC1) and 18 months (SC2). Outcomes on technical success, adverse events and recurrence were documented prospectively and then compared retrospectively between the subsequent time periods.

RESULTS

A total of 562 L-SSL in 474 patients were evaluated of which 156 L-SSL in 121 patients were treated by p-CSP and 406 L-SSL in 353 patients by EMR. Technical success was equal in both periods (100.0% (n=156) vs 99.0% (n=402)). No adverse events occurred in p-CSP, whereas delayed bleeding and DMI were encountered in 5.1% (n=18) and 3.4% (n=12) of L-SSL treated by EMR, respectively. Recurrence rates following p-CSP were similar to EMR at 4.3% (n=4) versus 4.6% (n=14) and 2.0% (n=1) versus 1.2% (n=3) for surveillance colonoscopy (SC)1 and SC2, respectively.

CONCLUSIONS

In a historical comparison on the endoscopic management of L-SSL, p-CSP is technically equally efficacious to EMR but virtually eliminates the risk of delayed bleeding and perforation. p-CSP should therefore be considered as the new standard of care for L-SSL treatment.

Incidence of microscopic residual adenoma after complete wide-field endoscopic resection of large colorectal lesions: evidence for a mechanism of recurrence

BACKGROUND AND AIMS

EMR of large (≥2 cm) nonpedunculated colorectal polyps (LNPCPs) is associated with high rates of recurrent/residual adenoma, possibly because of microadenoma left at the margin of resection. Data supporting this mechanism are required. We aimed to determine the incidence of residual microadenoma at the defect margin and base after EMR.

METHODS

We performed a retrospective observational study of patients undergoing EMR of large LNPCPs with the lateral defect margin further resected using the EndoRotor device (Interscope Medical, Inc, Worcester, Mass, USA) after confirming no visible residual adenomatous tissue. Aspects of the defect base were also resected in selected patients. Patients underwent surveillance at 3 to 6 months.

RESULTS

Resection of the normal defect margin was performed in 41 patients and of aspects of the base in 21 patients. Mean lesion size was 43.0 mm (range, 20-130). Microscopic residual lesion was detected in the margin of apparently normal mucosa in 8 cases (19%). In 7 cases this was an adenoma, and in 1 case a serrated lesion was found at the margin of a resected tubular adenoma. Microscopic residual lesion was detected at the base in 5 of 21 cases. Residual/recurrent adenoma was detected in 2 patients. Neither had residual microadenoma at the lateral margin or base detected after the primary resection.

CONCLUSIONS

Microscopic residual adenoma after wide-field EMR was detected in 19% of cases at the apparently normal defect margin and at the resection base in 5 of 21 cases. This study confirms the presence of residual microadenoma after resection of LNPCPs, providing evidence for the mechanism of 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.

Risk factors associated with adenoma recurrence following cold snare endoscopic mucosal resection of polyps ≥ 20 mm: a retrospective chart review

Background and study aims  Cold snare endoscopic mucosal resection (EMR) is being increasingly utilized for non-pedunculated polyps ≥ 20 mm due to adverse events associated with use of cautery. Larger studies evaluating adenoma recurrence rate (ARR) and risk factors for recurrence following cold snare EMR of large polyps are lacking. The aim of this study was to define ARR for polyps ≥ 20 mm removed by cold snare EMR and to identify risk factors for recurrence. Patients and methods  A retrospective chart review of colon cold snare EMR procedures performed between January 2015 and July 2019 at a tertiary care medical center was performed. During this period, 310 non-pedunculated polyps ≥ 20 mm were excised using cold snare EMR with follow-up surveillance colonoscopy. Patient demographic data as well as polyp characteristics at the time of index and surveillance colonoscopy were collected and analyzed. Results  A total of 108 of 310 polyps (34.8 %) demonstrated adenoma recurrence at follow-up colonoscopy. Patients with a higher ARR were older ( P  = 0.008), had endoscopic clips placed at index procedure ( P  = 0.017), and were more likely to be Asian and African American ( P  = 0.02). ARR was higher in larger polyps ( P  < 0.001), tubulovillous adenomas ( P  < 0.001), and polyps with high-grade dysplasia ( P  = 0.003). Conclusions  Although cold snare EMR remains a feasible alternative to hot snare polypectomy for resection of non-pedunculated polyps ≥ 20 mm, endoscopists must also carefully consider factors associated with increased ARR when utilizing this technique.

Large prolapse-related lesions of the sigmoid colon

BACKGROUND

Large prolapse-related lesions (LPRL) of the sigmoid colon have been documented histologically but may not be readily recognized endoscopically.

METHODS

Colonic lesions referred for endoscopic mucosal resection (EMR) were enrolled prospectively. Endoscopic features were carefully documented prior to resection. Final diagnosis was made based on established histologic criteria, including vascular congestion, hemosiderin deposition, fibromuscular hyperplasia, and crypt distortion.

RESULTS

Of 134 large ( ≥ 20 mm) sigmoid lesions, 12 (9.0 %) had histologic features consistent with mucosal prolapse. Distinct endoscopic features were: broad-based morphology; vascular pattern obscured by dusky hyperemia; blurred crypts of varying size and shape; and irregular spacing of sparse crypts. Focal histologic dysplasia was identified in 6 of 12 lesions (50.0 %).

CONCLUSIONS

LPRL of the sigmoid colon exhibit a distinct endoscopic profile. Although generally non-neoplastic, dysplasia may be present, warranting consideration of EMR.

Previously Attempted Large Nonpedunculated Colorectal Polyps Are Effectively Managed by Endoscopic Mucosal Resection

INTRODUCTION

Endoscopic mucosal resection (EMR) is an effective therapy for naive large nonpedunculated colorectal polyps (N-LNPCPs). The best approach for the treatment of previously attempted LNPCPs (PA-LNPCPs) is undetermined.

METHODS

EMR performance for PA-LNPCPs was evaluated in a prospective observational cohort of LNPCPs ≥20 mm. Efficacy was measured by technical success (removal of all visible polypoid tissue during index EMR) and recurrence at first surveillance colonoscopy (SC1). Safety was assessed by clinically significant intraprocedural bleeding, deep mural injury types III-V, clinically significant post-EMR bleeding, and delayed perforation.

RESULTS

From January 2012 to October 2019, 158 PA-LNPCPs and 1,134 N-LNPCPs underwent EMR. Median PA-LNPCP size was 30 mm (interquartile range 25-46 mm). Technical success was 93.0% and increased to 95.6% after adjusting for 2-stage EMR. Cold-forceps avulsion with adjuvant snare-tip soft coagulation (CAST) was required for nonlifting polypoid tissue in 73 (46.2%). Median time to SC1 was 6 months (interquartile range 5-7 months). Recurrence occurred in 9 (7.8%). No recurrence was identified among 65 PA-LNPCPs which underwent margin thermal ablation at SC1 vs 9 (18.0%; P < 0.001) which did not. There were significant differences in resection duration (35 vs 25 minutes; P < 0.001), technical success (93.0% vs 96.6%; P = 0.026), and use of CAST (46.2% vs 7.6%; P < 0.001), between PA-LNPCPs and N-LNPCPs. When adjusting for 2-stage EMR, no difference in technical success was identified (95.6% vs 97.8%; P = 0.100). No differences in adverse events or recurrence were identified.

DISCUSSION

EMR, using auxillary techniques where necessary, can achieve high technical success and low recurrence frequencies for PA-LNPCPs.

Evaluating learning curves and competence in colorectal EMR among advanced endoscopy fellows: a pilot multicenter prospective trial using cumulative sum analysis

BACKGROUND AND AIMS

Data on colorectal EMR (C-EMR) training are lacking. We aimed to evaluate C-EMR training among advanced endoscopy fellows (AEFs) by using a standardized assessment tool (STAT).

METHODS

This multicenter prospective study used a STAT to grade AEF training in C-EMR during their 12-month fellowship. Cumulative sum analysis was used to establish learning curves and competence for cognitive and technical components of C-EMR and overall performance. Sensitivity analysis was performed by varying failure rates. AEFs completed a self-assessment questionnaire to assess their comfort level with performing C-EMR at the completion of their fellowship.

RESULTS

Six AEFs (189 C-EMRs; mean per AEF, 31.5 ± 18.5) were included. Mean polyp size was 24.3 ± 12.6 mm, and mean procedure time was 22.6 ± 16.1 minutes. Learning curve analyses revealed that less than 50% of AEFs achieved competence for key cognitive and technical C-EMR endpoints. All 6 AEFs reported feeling comfortable performing C-EMR independently at the end of their training, although only 2 of them achieved competence in their overall performance. The minimum threshold to achieve competence in these 2 AEFs was 25 C-EMRs.

CONCLUSIONS

A relatively low proportion of AEFs achieved competence on key cognitive and technical aspects of C-EMR during their 12-month fellowship. The relatively low number of C-EMRs performed by AEFs may be insufficient to achieve competence, in spite of their self-reported readiness for independent practice. These pilot data serve as an initial framework for competence threshold, and suggest the need for validated tools for formal C-EMR training assessment.

Endoscopic Mucosal Resection and Endoscopic Submucosal Dissection

Therapeutic endoscopy is an emerging field within general surgery. This article explores the evidence for and usage of endoscopic mucosal resection and endoscopic submucosal dissection throughout the gastrointestinal tract. We aim to educate surgeons and provide an understanding of these techniques. With education and appropriate training, the surgeon will gain confidence and hopefully adopt these tools into their daily practice.

Cold snare piecemeal EMR of large sessile colonic polyps ≥20 mm (with video)

BACKGROUND AND AIMS

Conventional EMR using a hot snare is the standard of care for resection of large (≥20 mm) nonmalignant sessile colonic polyps. Serious adverse events are predominantly because of electrocautery. This could potentially be avoided by cold snare piecemeal EMR (CSP-EMR). This study aimed to evaluate the safety and efficacy of CSP-EMR of sessile colonic polyps sized ≥20 mm.

METHODS

All cases of CSP-EMR at 5 Australian academic hospitals for sessile polyps ≥20 mm over a 2-year period, from January 2016 to December 2017, were identified retrospectively. Efficacy was defined as the absence of residual or recurrent polyp tissue during the first surveillance colonoscopy (SC1) and second surveillance colonoscopy (SC2). Clinically significant intraprocedural or delayed adverse events and surveillance colonoscopy findings were assessed by reviewing medical records.

RESULTS

CSP-EMR was performed on 204 polyps sized ≥20 mm in 186 patients (men, 33.8%; median age, 68 years). SC1 for 164 polyps (80.4%) at a median interval of 150 days showed residual or recurrent polyp in 9 cases (5.5%; 95% confidence interval, 3%-11%). SC2 for 113 polyps (72.9%) at a median interval of 18 months showed late residual or recurrent polyp in 4 cases (3.5%; 95% confidence interval, .9%-8.5%) after a normal SC1. Intraprocedural bleeding was successfully treated in 4 patients (2.2%), whereas 7 patients (3.8%) experienced self-limited clinically significant post-EMR bleeding and 1 patient (.5%) required overnight observation for nonspecific abdominal pain that resolved spontaneously. None experienced other adverse events.

CONCLUSIONS

CSP-EMR of sessile colonic polyps ≥20 mm is technically feasible, effective, and safe. The adverse event rate and polyp recurrence rate were low. Randomized or large prospective trials are required to confirm the noninferiority and improved safety of CSP-EMR compared with conventional EMR and to further determine the polyp morphologies that are best suited for CSP-EMR.

Pathological assessment of endoscopic resections of the gastrointestinal tract: a comprehensive clinicopathologic review

Endoscopic resection (ER) allows optimal staging with potential cure of early-stage luminal malignancies while maintaining organ preservation. ER and surgery are non-competing but complementary therapeutic options. In addition, histological examination of ER specimens can either confirm or refine the pre-procedure diagnosis. ER is used for the treatment of Barrett's related early carcinomas and dysplasias, early-esophageal squamous cell carcinomas and dysplasias, early gastric carcinomas and dysplasia, as well as low-risk submucosal invasive carcinomas (LR-SMIC) and, large laterally spreading adenomas of the colon. For invasive lesions, histological risk factors predict risk of lymph node metastasis and residual disease at the ER site. Important pathological risk factors predictive of lymph node metastasis are depth of tumor invasion, poor differentiation, and lymphovascular invasion. Complete resection with negative margins is critical to avoid local recurrences. For non-invasive lesions, complete resection is curative. Therefore, a systematic approach for handling and assessing ER specimens is recommended to evaluate all above key prognostic features appropriately. Correct handling starts with pinning the specimen before fixation, meticulous macroscopic assessment with orientation of appropriate margins, systematic sectioning, and microscopic assessment of the entire specimen. Microscopic examination should be thorough for accurate assessment of all pathological risk factors and margin assessment. Site-specific issues such as duplication of muscularis mucosa of the esophagus, challenges of assessing ampullectomy specimens and site-specific differences of staging of early carcinomas throughout the gastrointestinal tract (GI) tract should be given special consideration. Finally, a standard, comprehensive pathology report that allows optimal staging with potential cure of early-stage malignancies or better stratification and guidance for additional treatment should be provided.

Optical evaluation: the crux for effective management of colorectal neoplasia

Advances in minimally invasive tissue resection techniques now allow for the majority of early colorectal neoplasia to be managed endoscopically. To optimize their respective risk-benefit profiles, and, therefore, appropriately select between endoscopic mucosal resection, endoscopic submucosal dissection, and surgery, the endoscopist must accurately predict the risk of submucosal invasive cancer and estimate depth of invasion. Herein, we discuss the evidence and our approach for optical evaluation of large (⩾ 20 mm) colorectal laterally spreading lesions.

Endoscopic mucosal resection is effective for laterally spreading lesions at the anorectal junction

OBJECTIVE

The optimal approach for removing large laterally spreading lesions at the anorectal junction (ARJ-LSLs) is unknown. Endoscopic mucosal resection (EMR) is a definitive therapy for colorectal LSLs. It is unclear whether it is an effective modality for ARJ-LSLs.

DESIGN

EMR outcomes for ARJ-LSLs (distal margin of ≤20 mm from the dentate line) in comparison with rectal LSLs (distal margin of >20 mm from the dentate line) were evaluated within a multicentre observational cohort of LSLs of ≥20 mm. Technical success was defined as the removal of all polypoid tissue during index EMR. Safety was evaluated by the frequencies of intraprocedural bleeding, delayed bleeding, deep mural injury (DMI) and delayed perforation. Long-term efficacy was evaluated by the absence of recurrence (either endoscopic or histologic) at surveillance colonoscopy (SC).

RESULTS

Between July 2008 and August 2019, 100 ARJ-LSLs and 313 rectal LSLs underwent EMR. ARJ-LSL median size was 40 mm (IQR 35-60 mm). Median follow-up at SC4 was 54 months (IQR 33-83 months). Technical success was 98%. Cancer was present in three (3%). Recurrence occurred in 15.4%, 6.8%, 3.7% and 0% at SC1-SC4, respectively. Among 30 ARJ-LSLs that received margin thermal ablation, no recurrence was identified at SC1 (0.0% vs 25.0%, p=0.002). Technical success, recurrence and adverse events were not different between groups, except for DMI (ARJ-LSLs 0% vs rectal LSLs 4.5%, p=0.027).

CONCLUSION

EMR is an effective technique for ARJ-LSLs and should be considered a first-line resection modality for the majority of these lesions.

Long-term outcomes of endoscopic treatment for colorectal laterally spreading tumor: a large-scale multicenter retrospective study from China

BACKGROUND

Laterally spreading tumor (LST) is a type of precancerous lesion of colorectal cancer with high malignant potential. The present study aimed to evaluate long-term outcomes of endoscopic treatment for LST in Chinese patients.

METHODS

This study was a retrospective review of data collected from 653 included patients with LST from six regional representative hospitals in China between January 2007 and January 2017. Demographic characteristics, endoscopic features of LST, operation-related data, and follow-up results were collected and analyzed.

RESULTS

LST-granular type (LST-G, 80.3%) was much more common than LST-non-grandular type (LST-NG, 19.7%). The overall submucosal invasion rate of all LSTs was 6.1% and the submucosal invasion rate of LST-NG was significantly higher than that of LST-G (6.79% vs. 3.87%, p = 0.000). The en bloc resection rate of ESD and EMR treatment was 96% and 93.7%, respectively, with pathologic R0 resection rate of 90.1% and 82.8%. After an average duration of follow-up about 34.52 ± 11.76 months, the recurrence rate of ESD was 3.47%, and the recurrence rate of EMR was 8.8% after an average follow-up of about 38.44 ± 4.42 months. However, the recurrence rate of ESD was much lower than piecemeal EMR for LST (3.47% vs. 8.62%, p = 0.017). Retroflexion-assisted technique applied for resection of rectal LST was associated with a significantly shortened operating time (85.40 min vs. 174.18 min, p = 0.002).

CONCLUSION

Endoscopic resection is a safe and efficient modality for the treatment of colorectal LST with a relatively low recurrence rate and shortened operating time with the use of retroflexion.

Clinical and financial impacts of introducing an endoscopic mucosal resection service for treatment of patients with large colonic polyps into a regional tertiary hospital

Background and study aims  Endoscopic mucosal resection (EMR) of large sessile or laterally spreading colonic lesions is a safe alternative to surgery. We assessed reductions in Surgical Resection (SR) rates and associated clinical and financial benefits following the introduction of an EMR service to a large regional center. Patients and methods  Ongoing prospective intention-to-treat analysis of EMR was undertaken from time of service inception in 2009 to 2017. Retrospective data for SR of large sessile/laterally spreading colonic lesions were collected for the period 4 years before commencement of the EMR service (2005 - 2008) and 9 years after its introduction (2009 - 2017). Results  From 2005 to 2008, 32 surgical procedures were performed for non-malignant colonic neoplasia (50 % male, median age 68 years, median Length of Stay (LoS) 10 days). Following the introduction of the EMR service, there was a 56 % reduction in the number of patients referred for surgery (32 surgical procedures, 47 % male, median age 70 years, median LoS 8.5 days). During this period, EMR was successfully performed in 183 patients with 216 lesions resected (60 % male, median age 68 years, median LoS 1 day). Compared to the SR group, the EMR cohort had a lower peri-procedural complication rate (7.7 % vs 54.7 %, P  < 0.0001), and shorter average LoS (1 vs 9 days, P  < 0.0001). A cost saving of AUD $ 19 543.5 was seen per lesion removed with EMR compared to SR. Conclusions  The introduction of a dedicated EMR service into a large regional center as an alternative to SR can lead to a substantial decrease in unnecessary surgery with subsequent clinical and financial benefits.

How to Perform Wide-Field Endoscopic Mucosal Resection and Follow-up Examinations

Wide-field endoscopic mucosal resection (EMR) is the primary management option for noninvasive laterally spreading colorectal lesions. It has been proved to be safe, highly effective, efficient, and cost-effective. Careful lesion interrogation before resection is essential because it provides essential information, including the risk of submucosal invasive disease. Adjuvant thermal ablation to the post-EMR defect margin has recently been shown to substantially reduce adenoma recurrence. Adenoma recurrence is predictable using the Sydney EMR Recurrence Tool. Adenoma recurrence can be accurately detected using standardized imaging of the post-EMR scar, and can be effectively treated.

Comparison of efficacy of colonoscopy between the morning and afternoon: A systematic review and meta-analysis

OBJECTIVE

Colonoscopy performed in the afternoon, rather than morning, has been reported to be associated with lower rates of adenoma and polyp detection (ADR and PDR) and cecal intubation (CIR). This meta-analysis evaluated the efficacy of afternoon colonoscopy relative to morning colonoscopy.

METHODS

The databases MEDLINE, Web of Science, EMBASE, and the Cochrane Library were searched to identify potential relevant studies. The primary outcome was ADR and the secondary outcomes were CIR and PDR. The outcomes were estimated by relative risk (RR) and 95% confidence interval (CI) with a random effects model.

RESULTS

Sixteen studies with 38,063 participants met the inclusion criteria. The pooled analyses indicated that ADR (RR: 1.08, 95% CI: 1.00-1.17) and CIR (RR: 1.01, 95% CI: 1.00-1.02) were stable during the whole day. In subgroup analyses, the effect of full-day block or inferior bowel preparation were more prominent, reflected by a significant reduction of ADR (RR: 1.18, 95% CI: 1.09-1.28; RR: 1.12, 95% CI: 1.01-1.24) and CIR (RR: 1.08, 95% CI: 1.02-1.13; RR: 1.02, 95% CI: 1.01-1.03) in the afternoon, respectively.

CONCLUSIONS

Colonoscopy quality, as indicated by the ADR and CIR, is not affected by the time of day for procedures performed in block shifts. However, endoscopists' working full-day blocks and inferior bowel preparation are associated with a significant decrease in ADR and CIR in the afternoon.

Advances in CRC Prevention: Screening and Surveillance

Colorectal cancer (CRC) is among the most commonly diagnosed cancers and causes of death from cancer across the world. CRC can, however, be detected in asymptomatic patients at a curable stage, and several studies have shown lower mortality among patients who undergo screening compared with those who do not. Using colonoscopy in CRC screening also results in the detection of precancerous polyps that can be directly removed during the procedure, thereby reducing the incidence of cancer. In the past decade, convincing evidence has appeared that the effectiveness of colonoscopy as CRC prevention tool is associated with the quality of the procedure. This review aims to provide an up-to-date overview of recent efforts to improve colonoscopy effectiveness by enhancing detection and improving the completeness and safety of resection of colorectal lesions.

Endoscopic Submucosal Dissection: Indications and Application in Western Endoscopy Practice

Endoscopic submucosal dissection was developed in Japan, early in this century, to provide a minimally invasive yet curative treatment for the large numbers of patients with early gastric cancer identified by the national screening program. Previously, the majority of these patients were treated surgically at substantial cost and with significant risk of short- and long-term morbidity. En-bloc excision of these early cancers, most with a limited risk of nodal metastasis, allowed complete staging of the tumor, stratification of the subsequent therapeutic approach, and potential cure. This transformative innovation changed the nature of endoscopic treatment for superficial mucosal neoplasia and, ultimately, for the first time allowed endoscopists to assert that the early cancer had been definitively cured. Subsequently, Western endoscopists have increasingly embraced the therapeutic possibilities offered by endoscopic submucosal dissection, but with some justifiable scientific caution. Here we provide an evidence-based critical appraisal of the role of endoscopic submucosal dissection in advanced endoscopic tissue resection.

Colorectal endoscopic mucosal resection (EMR)

Colonoscopy has the benefit of detecting and treating precancerous adenomatous polyps and thus reduces mortality associated with CRC. Screening colonoscopy is the keystone for prevention of colorectal cancer. Over the last 20 years there has been increased in the management of large colorectal polyps from surgery to endoscopic removal techniques which is less invasive. Traditionally surgical resection was the treatment of choice for many years for larger polyps but colectomy poses significant morbidity of 14-46% and mortality of up to 7%. There are several advantages of endoscopic resection technique over surgery; it is less invasive, less expensive, has rapid recovery, and preserves the normal gut functions. In addition patient satisfaction and efficacy of EMR is higher with minor complications. Thus, this has facilitated the development of advanced resection technique for the treatment of large colorectal polyps called as endoscopic mucosal resection (EMR).