Recurrence rates after EMR of large sessile serrated polyps

Distal cap-assisted EMR allows the safe and effective resection of adherent dysplastic lesions in the setting of inflammatory bowel disease: a multicenter retrospective study (with video)

BACKGROUND AND AIMS

EMR is established as the primary approach for large and complex dysplastic lesions. However, submucosal fibrosis caused by previous attempts at removal, biopsy sampling, inflammation, or tattoo placement can cause a benign "negative lift sign" and create difficulty for EMR. Here, we present the use of distal cap-assisted EMR (EMR-DC) specifically for the use of resecting dysplastic colonic lesions when submucosal fibrosis is present in patients with inflammatory bowel disease (IBD).

METHODS

Sixteen IBD patients were retrospectively evaluated from 2 high-volume centers. Patient demographics, lesion pathology and classification, outcomes including time and success of resection, serious adverse events (SAEs) within 30 days of the procedure, and efficacy were measured.

RESULTS

Seventy-five percent of patients treated with EMR-DC achieved complete resection with no SAEs within 30 days of the procedure.

CONCLUSIONS

EMR-DC represents an attractive option for the resection of adherent, dysplastic lesions in chronic IBD that is effective, safe, and inexpensive.

Cold Versus Hot Endoscopic Mucosal Resection for Sessile Serrated Colorectal Polyps ≥10 mm: A Systematic Review and Meta-analysis

INTRODUCTION

We performed a systematic review and meta-analysis studying the efficacy and safety of cold versus hot endoscopic mucosal resection (EMR) for resection of sessile serrated polyps (SSPs) ≥10 mm.

METHODS

Multiple databases were searched until January 2023 for studies reporting outcomes of cold versus hot EMR for SSPs ≥10 mm. The primary outcome was the residual SSP rate. Secondary outcomes included technical success rate, R0 resection rate, and adverse events. We used standard meta-analysis methods using the random-effects model, and I2 % was used to assess heterogeneity.

RESULTS

Thirteen studies were included in the final analysis. In all, 1896 SSPs were included with a mean polyp size of 23.7 mm (range, 15.9 to 33). A total of 1452 SSPs were followed up for a median follow-up duration of 15.3 months (range, 6 to 37). The pooled residual SSP rate for cold EMR was 4.5% (95% CI: 1.0-17.4), and 5.1% (95% CI: 2.4-10.4) for hot EMR ( P =0.9). The pooled rates of technical success, R0 resection, immediate bleeding, and perforation were comparable. Hot EMR was significantly associated with lower piecemeal resection (59.2% vs. 99.3%, P <0.001), higher en-bloc resection (41.4% vs. 1.4%, P <0.001), and delayed bleeding rate (4% vs. 0.7%, P =0.05) compared to cold EMR.

CONCLUSIONS

Cold EMR has similar efficacy compared to hot EMR for resection of SSP ≥ 10 mm, despite limitations in piecemeal R0 resection rate reporting. Although hot EMR was associated with a higher rate of en-bloc resection, it also showed an increased risk of delayed bleeding compared to cold EMR.

Histopathologic vertical margin positivity in cold snare polypectomy and mucosal resection for sessile serrated lesions

BACKGROUND AND AIMS

Data regarding the status of the vertical margin of sessile serrated lesions (SSLs) resected using cold snare polypectomy (CSP) are lacking, and whether a histopathologically positive vertical margin is related to recurrence remains unclear. Therefore, this preliminary study aimed to clarify the rates of positive or unassessable vertical and horizontal margins and the rate of muscularis mucosae resection in SSLs treated using CSP compared with those treated with EMR.

METHODS

Histologic outcomes of patients treated with CSP or EMR for SSLs were evaluated in this single-center observational study. The primary outcome was the incidence of histopathologically positive vertical margins in CSP and EMR. Furthermore, the comparisons were adjusted for confounding factors using propensity score matching.

RESULTS

Overall, 82 patients with SSLs were included in the CSP and EMR groups after matching. The incidence of positive histologic vertical margins in the CSP and EMR groups were 67.1% and 2.4%, respectively (P < .001). Regarding the evaluation of the presence of muscularis mucosae, 29.3% and 98.8% of patients in the CSP and EMR groups, respectively, had a complete muscularis mucosae resection (P < .001).

CONCLUSIONS

A rigorous histopathologic evaluation revealed that for SSLs, CSP more frequently leads to positive vertical margins than EMR. (Clinical trial registration number: UMIN 000051569.).

Cold EMR vs. Hot EMR for the removal of sessile serrated polyps larger than 10 mm: a systematic review and meta-analysis

BACKGROUND

Endoscopic mucosal resection (EMR) appears to be a promising technique for the removal of sessile serrated polyps (SSPs) ≥ 10 mm. To assess the effectiveness and safety of EMR for removing SSPs ≥ 10 mm, we conducted this systematic review and meta-analysis.

METHODS

We conducted a thorough search of Embase, PubMed, Cochrane, and Web of Science databases for relevant studies reporting on EMR of SSPs ≥ 10 mm, up until December 2023. Our primary endpoints of interest were rates of technical success, residual SSPs, and adverse events (AE).

RESULTS

Our search identified 426 articles, of which 14 studies with 2262 SSPs were included for analysis. The rates of technical success, AEs, and residual SSPs were 100%, 2.0%, and 3.1%, respectively. Subgroup analysis showed that the technical success rates were the same for polyps 10-19 and 20 mm, and en-bloc and piecemeal resection. Residual SSPs rates were similar in en-bloc and piecemeal resection, but much lower in cold EMR (1.0% vs. 4.2%, P = 0.034). AEs rates were reduced in cold EMR compared to hot EMR (0% vs. 2.9%, P = 0.168), in polyps 10-19 mm compared to 20 mm (0% vs. 4.1%, P = 0.255), and in piecemeal resection compared to en-bloc (0% vs. 0.7%, P = 0.169).

CONCLUSIONS

EMR is an effective and safe technique for removing SSPs ≥ 10 mm. The therapeutic effect of cold EMR is superior to that of hot EMR, with a lower incidence of adverse effects.

PROSPERO REGISTRATION NUMBER

CRD42023388959.

Summary and comparison of recently updated post-polypectomy surveillance guidelines

Recently, updated guidelines for post-polypectomy surveillance have been published by the U.S. Multi-Society Task Force (USMSTF), the British Society of Gastroenterology/Association of Coloproctology of Great Britain and Ireland/Public Health England (BSG/ACPGBI/PHE), the European Society of Gastrointestinal Endoscopy (ESGE), the Japan Gastroenterological Endoscopy Society (JGES), and the Korean Multi-Society Taskforce Committee. This review summarizes and compares the updated recommendations of these 5 guidelines. There are some differences between the guidelines for the recommended post-polypectomy surveillance intervals. In particular, there are prominent differences between the guidelines for 1-4 tubular adenomas < 10 mm with low-grade dysplasia (nonadvanced adenomas [NAAs]) and tubulovillous or villous adenomas. The USMSTF, JGES, and Korean guidelines recommend colonoscopic surveillance for patients with 1-4 NAAs and those with tubulovillous or villous adenomas, whereas the BSG/ACPGBI/PHE and ESGE guidelines do not recommend endoscopic surveillance for such patients. Surveillance recommendations for patients with serrated polyps (SPs) are limited. Although the USMSTF guidelines provide specific recommendations for patients who have undergone SPs removal, these are weak and based on very lowquality evidence. Future studies should examine this topic to better guide the surveillance recommendations for patients with SPs. For countries that do not have separate guidelines, we hope that this review article will help select the most appropriate guidelines as per each country's healthcare environment.

New Model to Predict Recurrence After Endoscopic Mucosal Resection of Non-pedunculated Colonic Polyps ≥ 20 mm

BACKGROUND

Polyp recurrence is common after endoscopic mucosal resection (EMR) of non-pedunculated colonic polyps ≥ 20 mm. Two models haven been published for polyp recurrence prediction: Sydney EMR recurrence tool (SERT) and the size, morphology, colonic site, and access to target (SMSA) score. None of these models have been evaluated in a real-world United States (U.S.) cohort. We aimed to evaluate the external validity of these two models and develop a new model.

METHODS

Retrospective cohort study of patients with non-pedunculated polyps ≥ 20 mm that underwent EMR between 1/1/2012 and 6/30/2020. Univariate and multivariate analysis were performed to identify predictors of polyp recurrence to build a new model. Receiver Operating Characteristic (ROC) curves for the new model, SERT and a modified version of SMSA were derived and compared.

RESULTS

A total of 461 polyps from 461 unique patients were included for analysis. The average polyp size was 29.1 ± 12.4 mm. Recurrence rate at first or second surveillance colonoscopy was 29.0% at a 15.6 months median follow up (IQR 12.3-17.4). A model was created with 4 variables from index colonoscopy: size > 40 mm, tubulovillous adenoma histology, right colon location and piecemeal resection. ROC curves showed that the Area Under the ROC (AUC) for the new model was 0.618, for SERT 0.538 and for mSMSA 0.550.

CONCLUSION

SERT score and mSMSA have poor external validity to predict polyp recurrence after EMR of non-pedunculated polyps > 20 mm. Our new model is simpler and performs better in this multiethnic, non-referral cohort from the U.S.

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.

Incomplete resection of colorectal polyps of 4-20 mm in size when using a cold snare, and its associated factors

BACKGROUND : Cold snare polypectomy (CSP) is increasingly used for polypectomy and is recommended as the first-line modality for small (< 10 mm) polyps. This study aimed to evaluate incomplete resection rates (IRRs) when using CSP for colorectal polyps of 4-20 mm. METHODS : Adults (45-80 years) undergoing screening, surveillance, or diagnostic colonoscopy and CSP by one of nine endoscopists were included. The primary outcome was the IRR for colorectal polyps of 4-20 mm, defined as the presence of polyp tissue in marginal biopsies after resection of serrated polyps or adenomas. Secondary outcomes included the IRR for serrated polyps, ease of resection, and complications. RESULTS:  413 patients were included (mean age 63; 48 % women) and 182 polyps sized 4-20 mm were detected and removed by CSP. CSP required conversion to hot snare resection in < 1 % of polyps of < 10 mm and 44 % of polyps sized 10-20 mm. The IRRs for polyps < 10 mm and ≥ 10 mm were 18 % and 21 %. The IRR was higher for serrated polyps (26 %) compared with adenomas (16 %). The IRR was higher for flat (IIa) polyps (odds ratio [OR] 2.9, 95 %CI 1.1-7.4); and when resection was judged as difficult (OR 4.2, 95 %CI 1.5-12.1), piecemeal resection was performed (OR 6.6, 95 %CI 2.0-22.0), or visible residual polyp was present after the initial resection (OR 5.4, 95 %CI 2.0-14.9). Polyp location, use of a dedicated cold snare, and submucosal injection were not associated with incomplete resection. Intraprocedural bleeding requiring endoscopic intervention occurred in 4.7 %. CONCLUSIONS : CSP for polyps of 4-9 mm is safe and feasible; however, for lesions ≥ 10 mm, CSP failure occurs frequently, and the IRR remains high even after technical success. Incomplete resection was associated with flat polyps, visual residual polyp, piecemeal resection, and difficult polypectomies.

Evolution of endoscopic mucosal resection (EMR) technique and the reduced recurrence of large colonic polyps from 2012 to 2020

BACKGROUND

Endoscopic mucosal resection (EMR) is an effective method for removing non-pedunculated polyps ≥ 20 mm. We aimed to examine changes in EMR techniques over a 9-year period and evaluate frequency of histologic-confirmed recurrence.

METHODS

We identified patients who underwent EMR of non-pedunculated polyps ≥ 20 mm at a safety net and the Veteran's Affairs (VA) hospital in Houston, Texas between 2012 and 2020. Odds ratios (ORs) and 95% confidence intervals (CI) for associations with recurrence risk were estimated using multivariable logistic regression.

RESULTS

461 unique patients were included. The histologic-confirmed recurrence was 29.0% at 15.6 months median follow up (IQR 12.3 - 17.4). Polyps removed between 2018 and 2020 had a 0.43 decreased odds of recurrence vs. polyps removed between 2012 and 2014. The use of viscous lifting agents increased over time (from 0 to 54%), and the use of saline was associated with increased risk of recurrence (OR 2.28 [CI 1.33 - 3.31]).

CONCLUSIONS

Histologic-confirmed recurrence after EMR for non-pedunculated polyps ≥ 20 mm decreased over the seven year-period. Saline was associated with a higher risk of recurrence and the use of more viscous agents increased over time.

Local recurrence after endoscopic resection of sessile serrated lesions: A multicenter prospective study by the Osaka Gut Forum

BACKGROUND AND AIM

Sessile serrated lesions (SSLs) act as precursors to colorectal cancer, sometimes harbor carcinomas, and are sometimes incompletely resected. We aimed to evaluate local recurrence after endoscopic resection of SSL ≥10 mm.

METHODS

This prospective, single-arm, observational study was performed at eight Japanese tertiary institutions. Colorectal lesions ≥10 mm were resected endoscopically, and the pathological diagnosis was either an SSL or hyperplastic polyp (HP). Follow-up colonoscopy was performed 1 year later, and the local recurrence was evaluated by biopsy.

RESULTS

From October 2018 to September 2021, 104 cases with 123 lesions were registered. Among the pathologically diagnosed 105 SSLs and 18 HPs, 95 and 7 lesions were diagnosed as SSLs and HPs, respectively, by central pathological review. Among the 104 endoscopically diagnosed SSLs, 86 were diagnosed as SSLs, whereas among the 11 endoscopically diagnosed HPs, two were diagnosed as HPs by central pathological review (the rest were SSLs). Among the 95 patients with 113 lesions who underwent follow-up colonoscopy, resection scars were identified in 95 (84%) lesions. Three (3.1%; 95% confidence interval 0.6-8.7%) local recurrences were diagnosed pathologically among 98 pathologically diagnosed SSLs. Two (6%) local recurrences were diagnosed in patients with SSLs ≥20 mm.

CONCLUSIONS

The local recurrence rate after endoscopic resection of SSLs ≥10 mm was 3.1%. Careful follow-up is recommended after endoscopic resection of large SSLs. Endoscopically diagnosed HPs ≥10 mm were sometimes pathologically diagnosed as SSL and should be considered for resection.

Snare tip soft coagulation (STSC) after endoscopic mucosal resection (EMR) of large (> 20 mm) non pedunculated colorectal polyps: a systematic review and meta-analysis

Background and study aims  Endoscopic mucosal resection (EMR) of laterally spreading tumors (LSTs) > 20 mm in size can be challenging. Piecemeal EMR of these lesions results in high rates of adenoma recurrence at first surveillance colonoscopy (SC1). Snare tip soft coagulation (STSC) of post resection margins is a safe and effective technique to prevent adenoma recurrence. We conducted a systematic review and meta-analysis to evaluate the effectiveness and safety of this technique. Patients and methods  Multiple databases were searched through April 2021 for studies that reported on outcomes of post EMR STSC for LSTs > 20 mm in size. Meta-analysis was performed to determine pooled odds of adenoma recurrence as well as pooled proportion of adverse events including intraprocedural and delayed bleeding as well as intraprocedural perforation events. Results  Six studies including two randomized controlled trials (RCT) and four cohort studies with 2122 patients were included in the final analysis. Overall pooled odds of adenoma recurrence at SC1 with post EMR STSC compared to no STSC was 0.27 (95 % 0.18-0.42; I2 = 0 %), P < 0.001. Pooled rate of adenoma recurrence at SC1 in post EMR STSC cohort was 6 %. Rates of intraprocedural bleeding, delayed bleeding and intraprocedural perforation were 10.3 %, 6.5 % and 2 % respectively. Conclusions  Our results show that thermal ablation of resection margins with STSC in LSTs > 20 mm is a safe and effective technique in reducing the incidence of adenoma recurrence.

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

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

Adverse events and residual lesion rate after cold endoscopic mucosal resection of serrated lesions ≥10 mm

BACKGROUND AND AIMS

Cold EMR is being increasingly used for large serrated lesions. We sought to measure residual lesion rates and adverse events after cold EMR of large serrated lesions.

METHODS

In a single academic center, we retrospectively examined a database of serrated class lesions ≥10 mm removed with cold EMR for safety and efficacy.

RESULTS

Five hundred sixty-six serrated lesions ≥10 mm in size were removed from 312 patients. We successfully contacted 223 patients (71.5%) with no reported serious adverse events that required hospitalization, repeat endoscopy, or transfusion. The residual lesion rate per lesion at first follow-up colonoscopy was 18 of 225 (8%; 95% confidence interval, 5-12.1). Lesions with residual were larger at polypectomy compared with lesions without recurrence (median, 23 mm versus 16 mm, P = .017).

CONCLUSION

Cold EMR appears to be safe and effective for the removal of large serrated lesions.

Efficacy and Safety of Endoscopic Resection of Sessile Serrated Polyps 10 mm or Larger: A Systematic Review and Meta-Analysis

BACKGROUND & AIMS

The best method for endoscopic resection of sessile serrated polyps (SSP) 10 mm or larger is unclear; studies report variable outcomes in comparison to conventional adenomas. We performed a systematic review and meta-analysis to assess the efficacy and safety of resection of SSPs 10 mm or larger in size.

METHODS

We searched the PubMed/MEDLINE, Google Scholar, Embase, and Cochrane databases for studies reporting data on endoscopic resection of SSPs 10 mm or larger, through May 31st, 2019. The primary outcome was rate of residual SSP, which was the rate of residual SSP found at the polypectomy site during the first follow-up colonoscopy. Secondary outcomes were: technical success (rate of complete macroscopic resection), R0 resection rate (complete histological resection with absence of any polyp tissue at the lateral and deep margins after en-bloc resection), and adverse events (immediate or delayed bleeding and perforation). We performed IQR,group analyses for outcomes based on polyp size and resection techniques. Pooled proportion rates (%) or odds ratio with 95% CIs with heterogeneity (I²) and P < .05.

RESULTS

A total of 14 studies met the inclusion criteria: 911 patients (50.2% male; mean age, 62.8 ± 4.9 years) who underwent resection of 1137 SSPs (574 SSPs ≥ 20 mm) with a median polyp size of 19.4 mm (interquartile range, 15.9-29.6 mm). Follow-up information was available for 832 SSPs with a median follow-up duration of 12 months (interquartile range, 6-22.5 months). Piecemeal resection was performed in 58.5% SSPs. The pooled residual SSP rate was 4.3% (95% CI, 2%-6.5%). There was a higher residual SSP rate for polyps ≥ 20 mm compared to 10-19 mm (5.9% vs 1.2%; odds ratio, 3.02; 95% CI, 1-9.2; P = .049). Cold endoscopic mucosal resection (EMR) had significantly lower rates of delayed bleeding (0 vs 2.3%; P = .03) and residual polyp rate (0.9% vs 5%; P=.01) compared to hot EMR, based on univariate analysis. In multi-variate analysis there was no difference in residual polyp rate. There was no significant difference in other outcomes based on the size or method of resection.

CONCLUSIONS

In a systematic review and meta-analysis, we found that SSPs ≥ 10 mm can be safely resected with low residual polyp rates. Polyp size ≥ 20 mm is a significant factor for residual polyp. Compared to hot EMR, cold EMR is associated with a lower rate of delayed bleeding. Randomized controlled trials comparing hot and cold resection are needed to standardize techniques and optimize outcomes.

Risk Factors for Recurrent Colorectal Polyps

The recurrence of colorectal polyps is caused by various factors and leads to the carcinogenesis of colorectal cancer, which ranks third in incidence and fourth in mortality among cancers worldwide. The potential risk factors for colorectal polyp recurrence have been demonstrated in multiple trials. However, an article that pools and summarizes the various results is needed. This review enumerates and analyzes some risk factors in terms of patient characteristics, procedural operations, polyp characteristics, and dietary aspects to propose some effective prophylactic measures. This review aimed to provide a reference for clinical application and guide patients to prevent colorectal polyp recurrence in a more effective manner.

Colorectal Cancer Screening for the Serrated Pathway

Serrated polyps are classified into hyperplastic polyps, sessile serrated adenomas/polyps, and traditional serrated adenomas. Although all serrated polyps share characteristic colonic crypts serrations, distinguishing hyperplastic polyps from sessile serrated adenomas/polyps is challenging. Traditional serrated adenomas are cytologically dysplastic lesions; sessile serrated adenomas/polyps develop cytologic dysplasia as they progress to colorectal cancer. A flat and pale appearance of serrated polyps may make detection difficult. Endoscopic mucosal resection has higher rates of complete resection. Close surveillance is recommended for sessile serrated adenomas/polyps, sessile serrated adenomas/polyp with dysplasia, hyperplastic polyps ≥10 mm, and traditional serrated adenomas.

Dissection-enabled scaffold-assisted resection (DeSCAR): a novel technique for resection of residual or non-lifting gastrointestinal neoplasia of the colon, expanded experience and follow-up

Background and study aims  Colonic lesions may not be amenable to conventional endoscopic mucosal resection (EMR) due to previous manipulation, submucosal invasion, or lesion flatness. In 2018, we described Dissection-enabled Scaffold Assisted Resection (DeSCAR) to be safe for the endoscopic resection of non-lifting or residual colonic lesions 1 In this study, we expand our original cohort to describe our expanded experience with patients undergoing DeSCAR and assess the efficacy, safety, and feasibility of DeSCAR for endoscopic resection of non-lifting or residual colonic lesions. Patients and methods  We retrospectively reviewed 57 patients from 2015-2019 who underwent DeSCAR for colonic lesions with incomplete lifting and/or previous manipulation. Cases were reviewed for location, prior manipulation, rates of successful resection, adverse events, and endoscopic follow up to assess for residual lesions. Results  Fifty-seven lesions underwent DeSCAR. Of the patients, 51 % were female, and average patient age was 69 years. Lesions were located in the cecum (n = 16), right colon (n = 27), left colon (n = 10), and rectum (n = 4). Average lesion size was 27.7 mm. Previous manipulation occurred in 54 cases (72 % biopsy, 44 % resection attempt, 18 % intralesional tattoo). The technical success rate for resection of non-lifting lesions was 98 %. There were two delayed bleeding episodes (one required endoscopic intervention) and one small perforation (managed by endoscopic hemoclip closure). Endoscopic follow up was available in 31 patients (54 %) with no residual adenoma in 28 patients (90 % of those surveilled). Conclusions  Our expanded experience with DeSCAR demonstrates high safety, feasibility, and effectiveness for the endoscopic management of non-lifting or residual colonic lesions.

Impact of observational training on endoscopic mucosal resection outcomes and competency for large colorectal polyps: single endoscopist experience

Background and study aims  Endoscopic mucosal resection (EMR) is standard treatment for large colorectal polyps. However, it is a specialized technique with limited data on the effectiveness of training methods to acquire this skill. The aim of this study was to evaluate the impact of observational training on EMR outcomes and competency in an early-stage endoscopist. Patients and methods  A single endoscopist completed comprehensive EMR training, which included knowledge acquisition and direct observation of EMR cases, and proctored supervision, during the third year of gastroenterology fellowship. After training, EMR was independently attempted on 142 consecutive, large (i. e., ≥ 20 mm), non-pedunculated colorectal polyps between July 2014 and December 2017 (mean age 61.7 years; mean polyp size 30.4 mm; en-bloc resection 55 %). Surveillance colonoscopy for evaluation of residual neoplasia was available for 86 % of the cases. Three primary outcomes were evaluated: endoscopic assessment of complete resection, rate of adverse events (AEs), and rate of residual neoplasia on surveillance colonoscopy. Results  Complete endoscopic resection was achieved in 93 % of cases, the rates of AEs and residual neoplasia were 7.8 % and 7.3 %, respectively. The rate of complete resection remained stable (at 85 % or greater) with increasing experience while rates of AEs and residual neoplasia peaked and decreased after 60 cases. Conclusions  An early-stage endoscopist can acquire the skills to perform effective EMR after completing observational training. At least 60 independent EMRs for large colorectal polyps were required to achieve a plateau for clinically meaningful outcomes.

Cold snare endoscopic resection of nonpedunculated colorectal polyps larger than 10 mm: a systematic review and pooled-analysis

BACKGROUND AND AIMS

Hot snare polypectomy and EMR are the standard of care in resecting colorectal polyps ≥10 mm. To avoid the risk of electrocautery-induced damage, there is recent evidence about using cold snare polypectomy and cold EMR for such lesions. The aim of this pooled analysis is to report outcomes of cold snare resection for polyps ≥10 mm.

METHODS

PubMed/Medline, Embase, Google Scholar, and Cochrane databases were searched up to July 2018 to identify studies that performed cold snare resection for colorectal polyps ≥10 mm. Primary outcomes were adverse events (bleeding, perforation, and postpolypectomy abdominal pain), and secondary outcomes were the rates of complete resection, overall residual polyp rates, and rates for adenomas versus sessile serrated polyps (SSPs). Subgroup analysis was performed focusing on lesion size, location, and resection technique.

RESULTS

Eight studies were included in the final analysis that included 522 colorectal polyps with a mean polyp size of 17.5 mm (range, 10-60). The overall adverse event rate was 1.1% (95% confidence interval, CI, 0.2%-2.0%; I2 = 0%). Intra- and postprocedural bleeding rates were .7% (95% CI, 0%-1.4%) and .5% (95% CI, .1%-1.2%), respectively, with abdominal pain rate being .6% (95% CI, .1%-1.3%). Polyps ≥20 mm had a higher intraprocedural bleeding rate of 1.3% (95% CI, .7%-3.3%) and abdominal pain rate of 1.2% (95% CI, .7%-3.0%) but no delayed bleedings. No perforations were reported. The complete resection rate was 99.3% (95% CI, 98.6%-100%). Overall pooled residual rates of polyps of any histology, adenomas, and SSPs were 4.1% (95% CI, .2%-8.4%), 11.1% (95% CI, 4.1%-18.1%), and 1.0% (95% CI, .4%-2.4%), respectively, during a follow-up period ranging from 154 to 258 days.

CONCLUSIONS

The results of this systematic review and pooled analysis were excellent with cold snare resection of colorectal polyps >10 mm in terms of postpolypectomy bleeding, complete resection, and residual polyp rates. Randomized controlled trials comparing cold snare resection with hot snare resections of polyps ≥10 mm are required for further investigation.

Low detection rate of advanced neoplasia within 5 years after polypectomy of small serrated adenoma

AIM

Patients with small serrated adenomas (SAs) (<10 mm) often undergo surveillance colonoscopy before the routine recommended time. We aimed to determine the appropriate surveillance intervals following polypectomy of small SAs for symptomatic patients.

METHOD

We retrospectively reviewed the data of 638 patients, including 122 cases and 516 controls. Subjects in the case group had small SAs at baseline colonoscopy, including sessile SA/polyps and traditional SAs, while subjects in the control group had negative findings. All patients underwent at least one surveillance colonoscopy during the following 5 years.

RESULTS

There was no significant difference in the incidence rate of advanced neoplasia between the two groups over a 5-year duration (3.6% vs 2.6%, p=0.455). Moreover, both groups also showed a low prevalence of SA formation over 1-5 years (3.6% vs 1.0%, p=0.145). Patients with baseline SA tended to undergo the first surveillance colonoscopy earlier than those without adenoma (≤1 year vs 1 to ≤3 years). Seventy-one (11.1%) of the total included subjects underwent inadequate initial colonoscopy, and 30 (42.3%) underwent early surveillance of adenoma formation within 1 year. Patients with a family history of colorectal cancer (OR 4.69, 95% CI 1.48 to 14.71, p=0.017) or inadequate baseline colonoscopy (OR 3.17, 95% CI 1.202 to 8.409, p=0.035) were at a higher risk of metachronous adenoma formation during the surveillance period.

CONCLUSION

Patients with small SAs at baseline gain little benefit from follow-up of colonoscopy within 5 years after complete polypectomy.

A retrospective comparative study of argon plasma versus polypectome snare tip coagulation: effect on recurrence rate after resection of large laterally spreading type lesions

Background

Endoscopic mucosal resection (EMR) is an established technique for treating large laterally spreading type (LST) lesions ≥20 mm. The aim of our study was to compare the use of argon plasma (APC) versus snare-tip coagulation on the recurrence rate of large LST lesions.

Methods

All patients with large LST lesions resected by EMR between January 2006 and December 2014 were enrolled. After piecemeal resection, patients underwent either APC or snare-tip coagulation of the rim of the resection area and any residual adenomatous tissue. Follow up included colonoscopy and biopsies. Medical records, including characteristics of patients and polyps, complications and recurrence were retrieved and collected.

Results

One hundred one patients were included in the final analysis. They were divided into the APC group (n=50) and the snare-tip coagulation group (n=51). The 2 groups were similar concerning patients’ characteristics, size of polyps and histology. Post-polypectomy coagulation syndrome was observed in 8 patients (7.9%) (APC group: n=5 and snare tip group: n=3). EMR-related bleeding occurred in 9 patients (8.9%) (APC group: n=4 and snare tip group: n=5). Total recurrence rate was 14.85% (16% and 13.7% in APC and snare-tip groups, respectively, P=0.34).

Conclusion

The effectiveness of snare-tip coagulation is comparable with that of APC with respect to recurrence rate after resection of large LST lesions. It thus represents a cost-effective alternative to APC.

Screening Relevance of Sessile Serrated Polyps

Conventional adenomas have historically been considered to be the only screening-relevant colorectal cancer (CRC) precursor lesion. The prevailing paradigm was that most CRCs arise along the chromosomal instability pathway, where adenomas accumulate incremental genetic alterations over time, leading eventually to malignancy. However, it is now recognized that this “conventional” pathway accounts for only about two-thirds of CRCs. The serrated pathway is responsible for most of the remainder, and is a disproportionate contributor to postcolonoscopy CRC. Hallmarks of the serrated pathway are mutations in the BRAF gene, high levels of methylation of promoter CpG islands, and the sessile serrated polyp (SSP). Accumulating evidence shows that SSPs can be considered adenoma-equivalent from the standpoint of CRC screening. SSPs have a higher prevalence than previously thought, and appear to have a relatively long dwell time similar to that of conventional adenomas. In addition, SSPs, whether sporadic or as part of the serrated polyposis syndrome, are associated with increased risk of synchronous and metachronous neoplasia. These features collectively support that SSPs are highly relevant to CRC prevention.

The dark side of the colon: current issues surrounding the significance, prevalence, detection, diagnosis and management of serrated polyps

PURPOSE OF REVIEW

Hyperplastic polyps, once considered to have no malignant potential, are now recognized to be part of a larger group of polyps known as serrated polyps. Serrated polyps can progress to CRC through an epigenetic pathway known as CpG Island Methylator Phenotype (CIMP), characterized by hypermethylation of specific DNA regions such as the promoter regions of the DNA mismatch repair genes like MLH1. The CIMP pathway is tightly linked with mutations of the oncogene BRAF. There are three subtypes of serrated polyps - hyperplastic polyps, sessile serrated polyps (SSPs) and traditional serrated adenomas (TSAs). TSAs harbor cytologic dysplasia whereas hyperplastic polyps and SSPs are nondysplastic lesions. Currently, only SSPs and TSAs are believed to progress to CRC whereas hyperplastic polyps are thought to be benign with no malignant potential. This article will review the current evidence while highlighting some of the issues regarding serrated polyps.

RECENT FINDINGS

One challenge has been pathologically distinguishing hyperplastic polyps from SSPs, which is an important distinction, given the potential for progression of SSPs to CRC. Other challenges regarding serrated polyps include adequate detection and resection. Surveillance guideline recommendations for some serrated polyps have been changed in current guidelines to reflect the malignant potential, recommending closer surveillance intervals than the 10-year follow-up that has been traditionally provided for hyperplastic polyps.

SUMMARY

Given the difficulties in diagnosing as well as resecting, it is important for endoscopists to know how to detect, resect and manage follow-up in patients with serrated polyps.

Management of local recurrence after endoscopic resection of neoplastic colonic polyps

A proportion of neoplastic polyps are incompletely resected, resulting in local recurrence, especially after resection of large polyps or piecemeal resection. Local recurrences that develop after endoscopic resection of intramucosal neoplasms that lacked risk factors for lymph node metastasis or positive vertical margins are usually treated endoscopically. Endoscopic submucosal dissection (ESD) is indicated for local residual or recurrent early carcinomas after endoscopic resection. However, ESD for such recurrent lesions is technically difficult and is typically a lengthy procedure. Underwater endoscopic mucosal resection (UEMR), which was developed in 2012, is suitable for recurrent or residual lesions and reportedly achieves superior en bloc resection rates and endoscopic complete resection rates than conventional EMR. However, a large recurrent lesion is a negative independent predictor of successful en bloc resection and of complete endoscopic removal. We therefore perform UEMR for relatively small (≤ 10-15 mm) recurrent lesions and ESD for larger lesions.

Sessile Serrated Adenomas: How to Detect, Characterize and Resect

Serrated polyps are important contributors to the burden of colorectal cancers (CRC). These lesions were once considered to have no malignant potential, but currently up to 30% of all CRC are recognized to arise from the serrated neoplasia pathway. The primary premalignant lesions are sessile serrated adenomas/polyps (SSA/Ps), although traditional serrated adenomas are relatively uncommon. Compared to conventional adenomas, SSA/Ps are morphologically subtle with indistinct borders, may be difficult to detect endoscopically, are more prevalent than previously thought, are associated with synchronous and metachronous advanced neoplasia, and have a higher risk of incomplete resection. Although many lesions remain “dormant,” progressive disease is associated with the development of dysplasia and more rapid progression to CRC. As a result, SSA/Ps are strongly implicated in the development of interval cancers. These factors represent unique challenges that require a meticulous approach to their management. In this review, we summarize the contemporary literature on the characterization, detection and resection of SSA/Ps.

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.

Dissection-enabled scaffold-assisted resection (DeSCAR): a novel technique for resection of residual or non-lifting GI neoplasia of the colon (with video)

BACKGROUND AND AIMS

As a result of previous manipulation or submucosal invasion, GI lesions referred for EMR frequently have flat areas of visible tissue that cannot be snared. Current methods for treating residual tissue may lead to incomplete eradication or not allow complete tissue sampling for histologic evaluation. Our aim is to describe dissection-enabled scaffold-assisted resection (DeSCAR), a new technique combining circumferential ESD with EMR for removal of superficial non-lifting or residual "islands" with suspected submucosal involvement/fibrosis.

METHODS

From 2015 to 2017, lesions referred for EMR were retrospectively reviewed. Cases were identified where lifting and/or snaring of the lesion was incomplete and the DeSCAR technique was undertaken. Cases were reviewed for location, previous manipulation, rates of successful hybrid resection, and adverse events.

RESULTS

Twenty-nine lesions underwent DeSCAR because of non-lifting or residual "islands" of tissue. Fifty-two percent of the patients were male and 48% were female; average age was 66 years (standard deviation ±9.9 years). Lesions were located in the cecum (n = 10), right side of the colon (n = 12), left side of the colon (n = 4), and rectum (n = 3). Average size was 31 mm (standard deviation ±20.6 mm). Previous manipulation had occurred in 28 of 29 cases (83% biopsy, 34% resection attempt, 52% tattoo). The technical success rate for resection of non-lifting lesions was 100%. There was one episode of delayed bleeding but no other adverse events.

CONCLUSIONS

DeSCAR is a feasible and safe alternative to argon plasma coagulation and avulsion for the endoscopic management of non-lifting or residual GI lesions, providing en bloc resection of tissue for histologic review. Further studies are needed to demonstrate long-term eradication and for comparison with other methods.

Polypectomy for complete endoscopic resection of small colorectal polyps

BACKGROUND AND AIMS

Small colorectal polyps are encountered frequently and may be incompletely removed during colonoscopy. The optimal technique for removal of small colorectal polyps is uncertain. The aim of this study was to compare the incomplete resection rate (IRR) by using EMR or cold snare polypectomy (CSP) for the removal of small adenomatous polyps.

METHODS

This was a prospective randomized controlled study from a tertiary-care referral center. A total of 358 patients who satisfied the inclusion criteria (polyp sized 6-9 mm) were randomized to the EMR (n =179) and CSP (n =179) groups, and their polyps were treated with conventional EMR or CSP, respectively. After polypectomy, an additional 5 forceps biopsies were performed at the base and margins of polypectomy sites to assess the presence of residual polyp tissue. The EMR and CSP samples were compared to assess the IRR.

RESULTS

Among a total of 525 polyps, 415 (79.0%) were adenomatous polyps, and 41 (16.4%) were advanced adenomas. The overall IRR for adenomatous polyps was significantly higher in the CSP group compared with the EMR group (18/212, 8.5% vs 3/203, 1.5%; P = .001). Logistic regression analysis revealed that the CSP procedure was a stronger risk factor for the IRR (odds ratio [OR] 6.924; 95% confidence interval [CI], 2.098-24.393; P = .003). In addition, piecemeal resection was the most important risk factor for the IRR (OR 28.696; 95% CI, 3.620-227.497; P = .001). The mean procedure time for polypectomy was not significantly different between the EMR and CSP groups (5.5 ± 2.7 vs 4.7 ± 3.4 minutes; P = .410). None of these patients presented with delayed bleeding. There were no severe adverse events related to the biopsies.

CONCLUSIONS

EMR was significantly superior to CSP for achieving complete endoscopic resection of small colorectal polyps. Patients with piecemeal resection of polyps had a higher risk for incomplete resection. (Clinical trial registration number: Hongwei-1102-12.).

Adjunctive use of chromoendoscopy may improve the diagnostic performance of narrow-band imaging for small sessile serrated adenoma/polyp

BACKGROUND AND AIM

Endoscopic diagnosis of sessile serrated adenoma/polyp (SSA/P) is challenging because of their subtle appearance. Narrow-band imaging (NBI) is useful for diagnosis, but its utility with concurrent chromoendoscopy (CE), especially to detect small SSA/P, is unproven.

METHODS

This prospective study enrolled 367 consecutive patients who underwent screening colonoscopy with the finding of serrated polyps. Patients were divided into derivation and validation cohorts: Diagnostic criteria using different endoscopic modalities were generated by regression analysis in the derivation cohort and were validated in the validation cohort for sensitivity, specificity, and accuracy.

RESULTS

There were 180 patients with 119 SSA/P and 147 hyperplastic polyps (HP) in the derivation cohort and 187 patients with 177 SSA/P and 125 HP in the validation cohort. With white-light endoscopy plus NBI, mucus cap, surface grooves, and expanded crypt were most associated with SSA/P. With white-light endoscopy plus CE, II-O pit pattern, mucus cap, and superficial telangiectasia were most associated with SSA/P. With the combined use of these three modalities, II-O pit pattern, mucus cap, and surface grooves were most associated with SSA/P. For large serrated polyp, NBI in combination with CE had a better accuracy than NBI alone (91% vs 86%, P = 0.025) to distinguish SSA/P from HP. CE alone had a better accuracy than NBI alone for distinguishing small SSA/P from small HP (85% vs 72%, P < 0.0001).

CONCLUSION

Compared with NBI alone, adjunctive use of CE can improve the diagnostic accuracy for distinguishing SSA/P from HP, especially for small SSA/P.

Serrated polyps - a concealed but prevalent precursor of colorectal cancer

Serrated polyps have long been considered to lack malignant potential but accumulating data suggest that these lesions may cause up to one-third of all sporadic colorectal cancer. Serrated polyps are classified into three subtypes, including sessile serrated adenomas/polyps (SSA/Ps), traditional serrated adenomas (TSAs), and hyperplastic polyps (HPs). SSA/P and TSA harbour malignant potential but TSA represents only 1-2%, wheras SSA/P constitute up to 20% of all serrated lesions. HPs are most common (80%) of all serrated polyps but are considered to have a low potential of developing colorectal cancer. Due to their subtle appearence, detection and removal of serrated polyps pose a major challenge to endoscopists. Considering that precancerous serrated polyps are predominately located in the right colon could explain why interval cancers most frequently appear in the proximal colon and why colonoscopy is less protective against colon cancer in the proximal compared to the distal colon. Despite the significant impact on colorectal cancer incidence, the aetiology, incidence, prevalence, and natural history of serrated polyps is incompletely known. To effectively detect, remove, and follow-up serrated polyps, endoscopists and pathologists should be well-informed about serrated polyps. This review highlights colorectal serrated polyps in terms of biology, types, diagnosis, therapy, and follow-up.

Endoscopic mucosal resection for large serrated lesions in comparison with adenomas: a prospective multicentre study of 2000 lesions

OBJECTIVE

Endoscopic mucosal resection (EMR) is effective for large laterally spreading flat and sessile lesions (LSLs). Sessile serrated adenomas/polyps (SSA/Ps) are linked to the relative failure of colonoscopy to prevent proximal colorectal cancer. We aimed to examine the technical success, adverse events and recurrence following EMR for large SSA/Ps in comparison with large conventional adenomas.

DESIGN

Over 74 months till August 2014, prospective multicentre data of LSLs ≥20 mm were analysed. A standardised dye-based conventional EMR technique followed by scheduled surveillance colonoscopy was used.

RESULTS

From a total of 2000 lesions, 323 SSA/Ps in 246 patients and 1527 adenomas in 1425 patients were included for analysis. Technical success for EMR was superior in SSA/Ps compared with adenomas (99.1% vs 94.5%, p<0.001). Significant bleeding and perforation were similar in both cohorts. The cumulative recurrence rates for adenomas after 6, 12, 18 and 24 months were 16.1%, 20.4%, 23.4% and 28.4%, respectively. For SSA/Ps, they were 6.3% at 6 months and 7.0% from 12 months onwards (p<0.001). Following multivariable adjustment, the HR of recurrence for adenomas versus SSA/Ps was 1.7 (95% CI 0.9 to 3.0, p=0.097). Subgroup analysis by lesion size revealed an eightfold increased risk of recurrence for 20-25 mm adenomas versus SSA/Ps, but no significantly different risk between lesion types in larger lesion groups.

CONCLUSION

Recurrence after EMR of 20-25 mm LSLs is significantly less frequent in SSA/Ps compared with adenomatous lesions. SSA/Ps can be more effectively removed than adenomatous LSLs with equivalent safety. Ensuring complete initial resection is imperative for avoiding recurrence.

TRIAL REGISTRATION NUMBER

ClinicalTrials.gov NCT01368289.

Clip retention rates and rates of residual polyp at the base of retained clips on colorectal EMR sites

BACKGROUND AND AIMS

Prophylactic endoscopic clipping may be effective in preventing delayed post-polypectomy hemorrhage after EMR of large colorectal lesions. The rate of retention of hemoclips on EMR sites has not been fully described. The aim of this study was to evaluate the adherence rates of hemoclips placed after EMR of large colorectal lesions.

METHODS

This was a retrospective review of a prospectively maintained database of large colorectal polyps (≥20 mm) referred to Indiana University Hospital between June 2006 and August 2015. Sites were closed with a mean of 4 clips. Patients were followed up for 3 to 6 months after EMR with a second follow-up 1 year later. Biopsy specimens of EMR scars were examined at follow-up, including the tissue at the base of retained clips.

RESULTS

There were 479 EMR sites in 424 patients that had first follow-up at our center with high-quality photographs of the EMR sites taken immediately after clip placement and at follow-up. Of 1407 Boston Scientific Resolution clips placed, 59 (4.2%) were retained at follow-up. Of 532 Cook Instinct clips placed, 46 (8.6%) were retained at first follow-up (P = .0001). There was no difference in the follow-up interval for the 2 clips. No patient had residual polyp by biopsy at the base of a retained clip.

CONCLUSIONS

Clip retention at first follow-up at 3 to 6 months after EMR was twice as high for the Cook Instinct clip compared with Boston Resolution clip but retention rates were low for both clips. Residual polyp at the base of retained clips was not a significant clinical problem.

High yield of synchronous lesions in referred patients with large lateral spreading colorectal tumors

BACKGROUND AND AIMS

There are few data on the prevalence of synchronous colorectal lesions in patients who have large lateral spreading tumors (LLSTs). We sought to describe the rate of synchronous lesions found in patients who underwent endoscopic resection of large sessile adenomas and serrated lesions.

METHODS

This is a retrospective assessment of a prospectively created database of 728 consecutive patients with resected LLSTs who underwent complete clearing of the colon during 2 colonoscopies by a single expert endoscopist.

RESULTS

The 728 patients with resected LLSTs and complete clearing had 4578 synchronous lesions, including 584 patients (80.2%) with at least 1 synchronous conventional adenoma, 132 (18.1%) with at least 1 synchronous conventional adenoma ≥ 20 mm in size, 294 (40.4%) with at least 1 synchronous advanced conventional adenoma, and 6 patients with a synchronous lesion with cancer. Patients with an index large sessile conventional adenoma compared with those with an index large serrated lesion had on average more synchronous conventional adenomas (4.8 vs 2.9, P = .001) and fewer synchronous serrated lesions (1.4 vs 4.5, P < .001). Of the 97 patients with a serrated class index lesion, 28 (28.9%) met criteria for serrated polyposis.

CONCLUSIONS

There is a very high prevalence of synchronous lesions, including other large and advanced synchronous lesions, in patients with flat or sessile conventional adenomas and serrated colorectal polyps. Patients with LLSTs in the colon need detailed clearing of the rest of the colon. Patients referred for endoscopic resection of serrated lesions ≥ 20 mm have a very high prevalence of serrated polyposis. This study has potential implications for further stratification of high-risk patient groups in postpolypectomy surveillance guidelines.

Large Sessile Serrated Polyps Can Be Safely and Effectively Removed by Endoscopic Mucosal Resection

BACKGROUND & AIMS

As many as 50% of large sessile serrated adenomas/polyps (SSPs) are removed incompletely, which is significant because SSPs have been implicated in the development of interval cancers. It is unclear if endoscopic mucosal resection (EMR) is an optimal method for removal of SSPs. We assessed the efficacy and safety of removal of SSPs 10 mm and larger using a standardized inject-and-cut EMR technique.

METHODS

We performed a retrospective analysis of colonoscopy data, collected over 7 years (2007-2013) at 2 centers, from 199 patients with proximal colon SSPs 10 mm and larger (251 polyps) removed by EMR by 4 endoscopists. The primary outcome measure was local recurrence. The secondary outcome measure was safety.

RESULTS

At the index colonoscopy, patients had a median of 1 serrated lesion (range, 1-12) and 1 nonserrated neoplastic lesion (range, 0-15). The mean SSP size was 15.9 ± 5.3 mm; most were superficially elevated (84.5%) and located in the ascending colon (51%), and 3 SSPs (1.2%) had dysplasia. Surveillance colonoscopies were performed on 138 patients (69.3%) over a mean follow-up period of 25.5 ± 17.4 months. Of these patients, 5 had local recurrences (3.6%; 95% confidence interval, 0.5%-6.7%), detected after 17.8 ± 15.4 months, with a median size of 4 mm. No patients developed postprocedural bleeding, perforation, or advanced colon cancer, or had a death related to the index colorectal lesion during the study period.

CONCLUSIONS

Inject-and-cut EMR is a safe and effective technique for the resection of SSPs. Less than 5% of patients have a local recurrence, which is usually small and can be treated endoscopically.

Frequency of coexistent carcinoma in sessile serrated adenoma/polyps and traditional serrated adenomas removed by endoscopic resection

BACKGROUND AND STUDY AIMS

Sessile serrated adenoma/polyps (SSA/Ps) have a different potential than traditional adenomatous polyps for developing into malignant colorectal cancer. However, little is known about the coexistent cancer rate. Here, we evaluate the frequency of carcinoma in serrated polyps removed by endoscopic resection (ER).

PATIENTS AND METHODS

This was a retrospective single-center cohort study of consecutive patients with colorectal polyps who underwent ER from March 2003 to October 2014. We determined the frequency of serrated polyps among all resected colorectal polyps and analyzed the clinicopathological findings as well as the frequency and characteristics of coexistent carcinoma in the serrated polyps resected by ER based on pathology reports.

RESULTS

A total of 21,048 polyps from 15,326 patients were identified, including 15,984 traditional adenomatous polyps (75.9 %), 621 SSA/Ps (3.0 %), 136 traditional serrated adenomas (TSAs) (0.6 %), 1,121 hyperplastic polyps (5.3 %), and 3,186 polyps of other types (15.1 %). The clinical and endoscopic findings of SSA/Ps revealed a male predominance (68.6 %), with 61.7 % of the polyps located in the proximal colon. Males accounted for 77.2 % of all patients with TSAs, and 77.2 % of these polyps were located in the distal colon. The mean sizes of the SSA/Ps and TSAs were 8.8 and 10.7 mm, respectively. Among the SSA/Ps, 8 (1.3 %) cases had coexistent carcinoma, and 1 (0.7 %) patient with TSA showed coexistent carcinoma. In the patients with SSA/Ps, female sex and a tumor size ≥ 10 mm were predictive factors for coexistent carcinoma.

CONCLUSIONS

The frequency of SSA/Ps with carcinoma was lower than that for traditional adenoma. Female sex and tumor size ≥ 10 mm were significant predictive factors for coexistent carcinoma.