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

BACKGROUND & AIMS: Thermal treatment of the defect margin after endoscopic mucosal resection (EMR) of large nonpedunculated colorectal lesions reduces the recurrence rate. Both snare tip soft coagulation (STSC) and argon plasma coagulation (APC) have been used for thermal margin treatment, but there are few data directly comparing STSC with APC for this indication. METHODS: We performed a randomized 3-arm trial in 9 US centers comparing STSC with APC with no margin treatment (control) of defects after EMR of colorectal nonpedunculated lesions ≥15 mm. The primary end point was the presence of residual lesion at first follow-up. RESULTS: There were 384 patients and 414 lesions randomized, and 308 patients (80.2%) with 328 lesions completed ≥1 follow-up. The proportion of lesions with residual polyp at first follow-up was 4.6% with STSC, 9.3% with APC, and 21.4% with control subjects (no margin treatment). The odds of residual polyp at first follow-up were lower for STSC and APC when compared with control subjects (P = .001 and P = .01, respectively). The difference in odds was not significant between STSC and APC. STSC took less time to apply than APC (median, 3.35 vs 4.08 minutes; P = .019). Adverse event rates were low, with no difference between arms. CONCLUSIONS: In a randomized trial STSC and APC were each superior to no thermal margin treatment after EMR. STSC was faster to apply than APC. Because STSC also results in lower cost and plastic waste than APC (APC requires an additional device), our study supports STSC as the preferred thermal margin treatment after colorectal EMR. (Clinicaltrials.gov, Number NCT03654209.).

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

BACKGROUND AND AIMS: Endoscopic submucosal dissection is increasingly promoted for the treatment of all large nonpedunculated colorectal polyps (LNPCPs) to cure potential low-risk cancers (superficial submucosal invasion without additional high-risk histopathologic features). The effect of a universal en bloc strategy on oncologic outcomes for the treatment of LNPCPs in the right colon is unknown. We evaluated this in a large Western population. METHODS: A prospective cohort of patients referred for endoscopic resection (ER) of LNPCPs was analyzed. Patients found to have cancer after ER and those referred directly to surgery were included. The primary outcome was to determine the proportion of right colon LNPCPs with low-risk cancer. RESULTS: Over 180 months until June 2023, 3294 sporadic right colon LNPCPs in 2956 patients were referred for ER at 7 sites (median size 30 [interquartile range 22.5-37.5] mm). A total of 63 (2.1%) patients were referred directly to surgery, and cancer was proven in 56 (88.9%). A total of 2851 (96.4%) of 2956 LNPCPs underwent ER (median size 35 [interquartile range 25-45] mm), of which 75 (2.6%) were cancers. The overall prevalence of cancer in the right colon was 4.4% (n = 131 of 2956). Detailed histopathologic analysis was possible in 115 (88%) of 131 cancers (71 after ER, 44 direct to surgery). After excluding missing histopathologic data, 23 (0.78%) of 2940 sporadic right colon LNPCPs were low-risk cancers. CONCLUSIONS: The proportion of right colon LNPCPs referred for ER containing low-risk cancer amenable to endoscopic cure was <1%, in a large, multicenter Western cohort. A universal endoscopic submucosal dissection strategy for the management of right colon LNPCPs is unlikely to yield improved patient outcomes given the minimal impact on oncologic outcomes. CLINICALTRIALS: gov, Numbers: NCT01368289, NCT02000141.

The impact of a multidisciplinary team approach on the management of patients diagnosed with complex colorectal polyps.

AIM: Large nonpedunculated colorectal polyps (LNPCPs) have a greater than average risk of malignancy, incomplete resection/recurrence and complications associated with treatment. Appropriate management of these lesions is crucial to prevent cancer and reduce harm. The British Society of Gastroenterologists (BSG) and the Association of Coloproctologists of Great Britain and Ireland (ACPGBI) published guidelines for the management of LNPCPs in 2015. The aim of this work was to evaluate the case mix and outcomes from a single centre's multidisciplinary approach to managing such lesions against the key performance indicators (KPIs) set within these national guidelines. METHOD: Cohort study from a single centre over a 2-year period, January 2020 to December 2022. RESULTS: After exclusions, a total of 229 cases were discussed. Most complex polyps were treated endoscopically, with conservative management recommended in 22 cases where patients had significant comorbidities and were unlikely to benefit from therapy. The overall surgical intervention rate (including transanal endoscopic microsurgery/per anal excision) was 14%. Of the cases treated endoscopically, there was residual polyp detected in 3.9% at 12-months' follow-up. Complications were rare. There was a single case of perforation following endoscopic submucosal dissection and no significant postprocedure bleeds. There were no perforations following endoscopic mucosal resection, although postpolypectomy bleeding requiring admission occurred in 4%. Sixty-eight per cent of patients were treated within 56 days of multidisciplinary team (MDT) discussion, despite the timeframe being within a period of huge disruption due to the global COVID pandemic. KPI standards published by the BSG were therefore met. CONCLUSION: MDT management of complex polyps (LNPCPs) is effective and meets the standards set by national guidance. Patient outcomes following treatment for complex polypectomy are improved when the most appropriate procedure is performed by the most appropriate operator. Discussion at a complex polyp MDT can facilitate this approach.

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.

Protocol design for randomized clinical trial to compare underwater cold snare polypectomy to conventional cold snare polypectomy for non-pedunculated colon polyps of size 5-10 mm (COLDWATER study).

BACKGROUND: Colorectal cancer is internationally the third leading cause of death from a malignant disease. The aim of screening colonoscopy in adults > 45 years of age is early diagnosis and treatment of precancerous polyps. Endoscopic polyp removal (polypectomy) can be achieved with various techniques depending on the size, morphology, and location of the polyp. According to current guidelines, small non-pedunculated polyps should be removed with a cold snare after the colorectal lumen has been insufflated with air (conventional cold snare polypectomy).In recent years, several studies have described the benefits of water aided colonoscopy, as well as the safety and efficacy of underwater cold snare polypectomy for large colon polyps. However, there are insufficient data on conventional and underwater techniques for small polyps, the most commonly diagnosed colorectal polyps. METHODS: We have designed a prospective randomized double-blind clinical trial to compare the safety and efficacy of conventional and underwater cold snare polypectomy for non-pedunculated polyps 5-10 mm in size. A total of 398 polyps will be randomized. Randomization will be carried out using the random numbers method of Microsoft Excel 2016. The primary endpoint is the muscularis mucosa resection rate. Secondary endpoints are the depth and percentage of R0 excisions, complications, and the recurrence rate at follow-up endoscopy 6-12 months after polypectomy. DISCUSSION: We hypothesize underwater polypectomy will result in a higher muscularis mucosa resection rate. The results of our study will provide useful data for the development of guidelines in polypectomy techniques for non-pedunculated polyps 5-10 mm in size. CLINICAL TRIAL REGISTRATION: Clinicaltrials.gov, NCT05273697.

The Role of Clips in Preventing Delayed Bleeding After Colorectal Polyp Resection: An Individual Patient Data Meta-Analysis.

BACKGROUND & AIMS: Nonpedunculated colorectal polyps are normally endoscopically removed to prevent neoplastic progression. Delayed bleeding is the most common major adverse event. Clipping the resection defect has been suggested to reduce delayed bleedings. Our aim was to determine if prophylactic clipping reduces delayed bleedings and to analyze the contribution of polyp characteristics, extent of defect closure, and antithrombotic use. METHODS: An individual patient data meta-analysis was performed. Studies on prophylactic clipping in nonpedunculated colorectal polyps were selected from PubMed, Embase, Web of Science, and Cochrane database (last selection, April 2020). Authors were invited to share original study data. The primary outcome was delayed bleeding ≤30 days. Multivariable mixed models were used to determine the efficacy of prophylactic clipping in various subgroups adjusted for confounders. RESULTS: Data of 5380 patients with 8948 resected polyps were included from 3 randomized controlled trials, 2 prospective, and 8 retrospective studies. Prophylactic clipping reduced delayed bleeding in proximal polyps ≥20 mm (odds ratio [OR], 0.62; 95% confidence interval [CI], 0.44-0.88; number needed to treat = 32), especially with antithrombotics (OR, 0.59; 95% CI, 0.35-0.99; number needed to treat = 23; subgroup of anticoagulants/double platelet inhibitors: n = 226; OR, 0.40; 95% CI, 0.16-1.01; number needed to treat = 12). Prophylactic clipping did not benefit distal polyps ≥20 mm with antithrombotics (OR, 1.41; 95% CI, 0.79-2.52). CONCLUSIONS: Prophylactic clipping reduces delayed bleeding after resection of nonpedunculated, proximal colorectal polyps ≥20 mm, especially in patients using antithrombotics. No benefit was found for distal polyps. Based on this study, patients can be identified who may benefit from prophylactic clipping. (PROSPERO registration number CRD42020104317.).

Linear-array EUS improves the accuracy of predicting deep submucosal invasion in non-pedunculated rectal polyps compared with radial EUS: a prospective observational study.

BACKGROUND: Radial endoscopic ultrasound (EUS) is typically used to estimate the depth of rectal polyp invasion, however, there are no data on linear EUS in this setting and its relative accuracy compared to radial EUS. METHODS: In this prospective cohort study, 89 patients with non-pedunculated rectal polyp who underwent linear EUS or radial EUS were prospectively enrolled. The invasion depth was measured for each polyp and categorized as mucosal to shallow submucosal(SMs) or deep submucosal(SMd) invasion. Invasion measurements were compared with the final diagnosis on histopathology. RESULTS: A total of 58 patients underwent radial EUS and 31 patients underwent linear EUS examination. There were 38 lesions correctly diagnosed in the radial EUS group and 29 correctly diagnosed lesions in the linear EUS group. The diagnostic accuracy of SMd invasion for linear EUS was significantly higher than radial EUS (0.936 vs. 0.655, p = 0.003). A significant difference was also noted for specificity between the two groups (0.963 vs. 0.659, p = 0.003). Univariate analysis showed radial EUS type (OR 0.131, 95% CI 0.028-0.606, p = 0.009) to be an independent predictor for incorrect diagnosis. The area under the receiver operating curve (ROC) was 0.856 and 0.651 for linear EUS and radial EUS, respectively. It was noted that four patients underwent unnecessary surgery for radial EUS while there were no such patients in the linear EUS group. CONCLUSIONS: Linear EUS was more accurate for determining SMd invasion and contributed to the selection of appropriate treatment modalities in patients with non-pedunculated rectal polyp.

Safety of endoscopic mucosal resection (EMR) of large non-pedunculated colorectal adenomas in the elderly.

BACKGROUND: Endoscopic mucosal resection (EMR) has been proven to be safe and effective for the treatment of colorectal adenomas. However, data are limited on the safety of this technique for large polyps and in elderly patients. Aims of our study were to examine the bleeding and perforation rates in patients with large non-pedunculated adenomas (≥20mm) and to evaluate the influence of size (≥40mm) and age (≥75 years) on the complication rates. METHODS: In this multicenter retrospective study, patients who underwent EMR of non-pedunculated adenomas ≥20mm between January 2012 and March 2016 were included. The demographics of the patients, the use of antithrombotic drugs, size of the polyps, type of resection, pathology report, occurrence of post-polypectomy bleeding, and perforation- and recurrence rate were collected. RESULTS: In 343 patients, 412 adenomas were removed. Eighty patients (23.3%) were ≥75 years of age, 138 polyps (33.5%) were ≥40mm. Bleeding complications were observed in 28 cases (6.8%) and were found significantly more frequent in adenomas ≥40mm, independent of the use of antithrombotic therapy. Five perforations (1.2%) were described, not related to the size of the polyp. There was no significant difference in complication rates between patients <75 years and patients ≥75 years. Bleeding complications rates were significantly higher in patients receiving double antithrombotic therapy. CONCLUSION: EMR is safe in elderly patients. EMR of adenomas of ≥40mm was associated with more bleeding complications. Future studies should address how the bleeding rates can be reduced in these patients, especially in those who use double antithrombotic treatment.

Efficacy and Safety of Gel Immersion Endoscopic Mucosal Resection for Non-Pedunculated Colorectal Polyps.

Underwater endoscopic mucosal resection (UEMR) has become a popular endoscopic resection method for large colorectal neoplasms. However, visualization can be poor during UEMR due to the presence of intestinal fluid. Gel immersion endoscopic mucosal resection (GIEMR), using a specially developed gel (Viscoclear®, Otsuka Pharmaceutical Factory, Tokushima, Japan), can improve the visual field. However, reports of GIEMR for colorectal polyps are limited. Herein, we evaluated the short-term outcomes of GIEMR for non-pedunculated colorectal neoplasms (NPCRN). This single-center, retrospective, and observational study includes 25 lesions in 20 patients with NPCRN who underwent GIEMR between January and October 2022. The short-term outcomes and adverse events were evaluated. The lesion locations were as follows: right colon, 18 lesions; left colon, 7 lesions; and rectum, none. The median tumor diameter was 15 (IQR, 10-18) mm. Histological classification was as follows: sessile serrated lesion, 9 cases; adenoma, 12 cases; and intramucosal adenocarcinoma, 4 cases. The overall en bloc resection rates and R0 resection rates were 80% (20/25) and 72% (18/25). For NPCRN in 10-19 mm, the en bloc resection rate was 75% (12/16), with an R0 resection rate of 69% (11/16). No post-polypectomy bleeding, perforation, or post-coagulation syndrome were observed. The findings of our study provide preliminary evidence of the efficacy and safety of GIEMR for NPCRN. Therefore, GIEMR may be a promising novel endoscopic resection method for NPCRN.

Prevention of late complications of endoscopic resection of colorectal lesions with a coverage agent: Current status of gastrointestinal endoscopy.

Endoscopic ectomy of large nonpedunculated colorectal lesions (≥ 20 mm) might cause significant adverse incidents, such as delayed perforation and delayed bleeding, despite the closure of mucosal lesions with clips. The conventional utilization of prophylactic clipping has not decreased the risk of postprocedural delayed adverse events, and additional outcomes and cost-effectiveness research is needed for patients with proximal lesions ≥ 20 mm, in whom prophylactic clipping might be useful. Coverage of the wound after endoscopic excision offers shield protection against delayed concomitant diseases.

Evaluation of blue laser endoscopy for detecting colorectal non-pedunculated adenoma.

BACKGROUND AND STUDY AIMS: Non-pedunculated lesions are easily missed on endoscopy, and histopathological examination shows that some of these lesions are adenomas. Adenoma is a precursor of colorectal cancer, a common tumor of the digestive tract. This study was conducted to compare the detection efficacy of non-pedunculated lesions in the same patient under different modes of blue laser endoscopy and to determine whether the surface pattern of the sample was consistent with its histopathological results. PATIENTS AND METHODS: A total of 91 patients with non-pedunculated lesions diagnosed at our hospital between April 2018 and March 2019 were included in this study. White light imaging (WLI), linked color imaging (LCI), and blue laser imaging (BLI) modes were used to record the location, number, and Hiroshima classification of the surface patterns of the non-pedunculated lesions. The lesions were removed by different endoscopic excision methods for histopathological examination; the histopathological results were compared with the surface patterns. RESULTS: A total of 105, 198, and 223 lesions were detected using the WLI, BLI, and LCI modes, respectively. The Wilcoxon signed rank test revealed a significant difference in the number of lesions detected using each observation mode (p < 0.01). The non-pedunculated lesions were primarily located in the rectum and transverse colon, followed by the sigmoid, descending, and ascending colon. The efficacy of LCI and BLI modes was better than that of WLI mode for detecting the non-pedunculated lesions measuring < 5 mm in size (p < 0.05). The surface pattern was not detected by the WLI mode. The surface patterns detected using the LCI and BLI modes were primarily types A and B. Histopathological results of the non-pedunculated lesions included inflammatory polyp, hyperplastic polyp, tubular adenoma, and adenoma. Surface patterns could not be detected using the WLI mode. The McNemar's test revealed a significant difference between the WLI mode findings and the histopathological results (p < 0.01). No significant difference was observed between the histopathological results and the surface patterns detected using the LCI mode (kappa = 0.57); the agreement was poor. There was also no significant difference between the histopathological results and the surface patterns detected using the BLI mode (kappa test, p < 0.01; kappa = 0.88); hence, there was good agreement between the surface patterns detected using the BLI mode and the histopathological results. CONCLUSION: The detection rate of colorectal non-pedunculated lesions may be improved using blue laser endoscopy. Non-pedunculated colorectal adenomas could be identified more accurately using the BLI mode, which might improve the adenoma detection rate, thus indicating that BLI is a feasible option in the practical settings.

Cold snare endoscopic resection of nonpedunculated colorectal polyps larger than 10 mm. A retrospective series.

BACKGROUND AND AIMS: Cold snare polypectomy (CSP) is an accepted technique to remove diminutive or small (6-9 mm) polyps. Here we present a series of CSP for advanced non-pedunculated polyps (> 10 mm). PATIENTS AND METHODS: This is a retrospective, single operator study. A total of 111 patients with non-pedunculated polyps (Paris classification 0-IIa, 0-IIb, 0-Is) estimated > 10 mm, underwent CSP. RESULTS: A total of 129 polyps were removed (87 0-IIa, 18 0-IIb, 24 0-Is). The number of these polyps ranked according to size were as follows : 11-19 mm : 63 (49%), 20-29 mm : 44 (34%), > 30 mm : 22 (17%). Thirty-eight (29.5%) were sessile serrated adenomas, 47 (36%) were tubular adenomas, 25 (19.3%) were villous adenoma's and 18 (14%) were hyperplastic polyps. Forty-nine (38%) polyps were resected in a piecemeal fashion, submucosal injection with diluted Indigo Carmine was used in 24 (19%). Immediate oozing bleeding was frequent but in almost all patients rapid spontaneous haemostasis occurred. In only one patient haemostatic clipping was required (in order to achieve hemostasis). Preventive clipping was used in 3 patients. There were no complications. Seventy-two patients (with 87 lesions) had a follow-up colonoscopy. Of these 87 lesions, 9 had residual adenomatous tissue (10.3 %). According to the size of the original polyp, the distribution was as follows: 11-19 mm : 2/36 (5.5 %), 20-29 mm : 4/32 (12.5 %), > 30 mm : 3/19 (15.7%). CONCLUSION: CSP for advanced, non-pedunculated lesions is feasible, effective and extremely safe.