Endoscopic Mucosal Resection Technique Research Articles

224 Is Completing Advance Endoscopy Fellowship Necessary to Perform Adequate Endoscopic Mucosal Resection to Remove Large Colon Polyps?

INTRODUCTION: Objective: The efficacy of Endoscopic mucosal resection (EMR) of large colon polyp could be addressed by assessing the recurrence rate, complication rates, and the number of procedures needed to eradicate the residual tissue. Aims: Assess risk factors for recurrence after EMR of large colon polyps and compare EMR efficacy between endoscopists who completed advanced endoscopy fellowship and skilled endoscopists who did not complete advance endoscopy fellowship. METHODS: We identified all patients with documented large colonic treated using EMR technique at Carilion Clinic, Roanoke between 01/01/2014–12/31/2017, with follow-up through 10–2018. Information on demographics, clinical and pathological features of high-risk polyps, number and 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. Risks associated with polyp recurrence were assessed using multivariate Cox proportional hazard analysis. RESULTS: One hundred and thirty patients (Mean age, 64.2 ± 10.7 yrs; 43.1% males) with large polyps removed using EMR (61 (46.9%) removed by advanced endoscopists (group 1) and 69 (53.1%) removed by non-advanced endoscopist (group 2)) were identified. Most of the polyp resected were located in the right colon (70.8%) and 60 (46.1%) removed in piecemeal fashion. At follow-up endoscopy, 37/130 (28.5%) developed polyp recurrence at the polypectomy site within a median of 5.5 months. The mean number of procedures needed to eradicate the residual tissue was 1.37 ± 0.64 and the resection was complicated by delayed bleeding in 6 cases (3 in each group). The median recurrence after polypectomy was not different between the two groups (1.76 yrs vs. 1.04 yrs, P = 0.26) (Figure 1). Using multivariate analysis, Prolonged withdrawal time (RR, 1.02; 95% CI, 1.003–1.027, P-value <0.01) and increased number of endoclips used to close the defect (RR, 1.2; 95% CI, 1.05–1.40, P-value <0.01) were found to be associated with high risk of polyp recurrence after resection. CONCLUSION: Polyp recurrence rates after EMR were not different between enodoscopists who completed advanced endoscopy training and the ones who did not. Prolonged withdrawal time and increased number of endoclips deployed to close the polypectomy defect were associated with increased risk for polyp recurrence.

283 Too Few or Too Many Endoclips to Close Polypectomy Defect After Endoscopic Mucosal Resection?

INTRODUCTION: Endoclips could be placed prophylactically at the polypectomy site after the removal of large polyps to prevent post-polypectomy bleeding. The effect of an increased number of endoclips deployed after endoscopic mucosal resection (EMR) on polyp recurrence is unknown. AIMS: Evaluate the risk of polyp recurrence in patients with large polyps undergoing EMR based on the number of endocips deployed. METHODS: We identified all patients with documented large colon polyps treated using EMR technique at Carilion Clinic, Roanoke between 01/01/2014–12/31/2017, with follow-up through 10-2018. Information on demographics, clinical and pathological features of high-risk polyps, additional treatments required, number of endoclips used, and number and timing of surveillance endoscopies were extracted. The cumulative risks of polyp recurrence after first resection using EMR technique were estimated using Kaplan-Meier curves. RESULTS: One-hundred and thirty patients (Mean age, 64.2 ± 10.7 yrs; 43.1% males) with polyps removed using EMR (60 (46.2%) removed in piecemeal fashion, 70 (53.8%) removed en bloc) were identified. The mean size of polyps resected was 2.12 ± 1.12. Argon plasma coagulation and/or the tip of the snare were used to cauterize remnant polyps in 42/130 (32%). Eighty-six patients (66.2%) required endoclips deployment to close the polypectomy defect (Table 1). At follow-up endoscopy, 14/53 (26.4%) in group 1 and 14/33 (42.4%) in group 2 developed polyp recurrence at the polypectomy site within a median of 5.9 months. The median time for recurrence after polypectomy was longer for pts in group 1 as compared to those in group 2 (P < 0.01) (Figure 1). After excluding patients receiving cauterization of the remaining polypoid tissue after EMR, median time for recurrence after polypectomy remained longer for pts in group 1 (P = 0.03) (Figure 2). Late post-polypectomy bleeding occurred despite endoclips deployment in 2/53 (3.8%) in group 1 and 4/33 (12.1%) in group 2. CONCLUSION: Large polyps EMR appear to be associated with higher recurrence rate in lesions requiring more than three endoclips. These findings need to be confirmed in prospective trials.

125 Underwater Versus Conventional Endoscopic Mucosal Resection for the Treatment of Colorectal Laterally Spreading Tumors: Results From an International, Multicenter, Randomized Controlled Trial

INTRODUCTION: Safe and effective resection of large colonic polyps remains a challenge for the practicing endoscopist. Recently, an underwater technique for endoscopic mucosal resection (UEMR) has emerged as an alternative to conventional injection-assisted EMR (CEMR). While the effectiveness of UEMR technique seems to be borne out in several case series and retrospective analyses, prospective data regarding its performance against CEMR technique is lacking. METHODS: This study was a prospective international multicenter randomized controlled trial involving 4 tertiary referral centers, 3 in the US and 1 in Italy, in order to compare the outcomes and safety of UEMR versus CEMR technique for large colon polyps (15 mm or larger). Block randomization was used to assign patients to either the UEMR arm or CEMR arm. Primary outcome was the rate of curative resection, as documented by presence of residual neoplasia on 3–6 month surveillance colonoscopy. Secondary outcomes included resection time, total procedure time, en bloc resection rates, and adverse events. RESULTS: A total of 303 patients with 303 lesions were enrolled in this trial. 145 patients were randomized into the CEMR arm, and 158 patients were enrolled in the UEMR arm. Among those in the CEMR arm, 13 patients crossed over into the UEMR arm at the discretion of the performing endoscopist. Among those in the UEMR arm, 1 patient crossed over to the CEMR arm. At follow up, a total of 95 patients had surveillance colonoscopy performed in the CEMR arm, with residual neoplasia found in 16 of these patients (16.8%). In the UEMR arm, 118 patients followed up, with residual neoplasia found in 10 of these patients (8.5%) [P = 0.06] The resection time and total procedure time were found to be less in the UEMR arm and there was a significantly higher rate of en bloc resection achieved by UEMR versus CEMR (P < 0.01). There was no difference in the rate of adverse events. CONCLUSION: This large multicenter randomized study supports that UEMR technique is a safe and effective alternative to CEMR technique and should be considered a first line option in the management of large laterally spreading colorectal tumors.

225 Barriers to Endoscopic Mucosal Resection of Large Colorectal Lesions: Results of a Nationwide Survey

INTRODUCTION: Over 90% of complex colon polyps that lack overt features of cancer can be removed using endoscopic mucosal resection (EMR) techniques. EMR is more cost-effective and is associated with less morbidity and mortality than surgery. However, rates of surgical resection have been rising even though extensive evidence suggests endoscopic resection should be first line for the management of complex colon polyps. We aimed to assess perceived barriers towards the utilization of EMR for >2 cm polyps among American endoscopists. METHODS: We administered a 21 question web-based survey with Qualtrics software (Provo, UT, USA). The American College of Gastroenterology distributed the survey to their mailing list on January 24, 2019 and closed it on February 21, 2019. We assessed endoscopist and practice characteristics as well as perceived barriers and facilitators of EMR, and compared responses between providers who performed 0–1 EMR per month with 2 or more EMR per month to determine which barriers and facilitators influence the utilization of EMR. RESULTS: A total of 8,797 practitioners received the survey, with 415 replies (4.7%). Provider demographics are summarized in Table 1. 275 providers (66.7%) reported performing 2 or more EMRs per month. 146 providers (35.1%) felt their fellowship prepared them poorly for large polyp resection. 237 providers (57.1%) felt that the incorporation of EMR training into fellowship would be very beneficial, followed by higher reimbursement (N = 176, 42.4%) and training on EMR technique (N = 154, 37.1%). Providers who performed 1 or fewer EMR per month were significantly more likely to report that lack of structured training, fear of complications, and uncertainty regarding which lesions were amenable to endoscopic management were barriers to routine use of EMR than providers who performed 2 or more EMR per month (Figure 1). They were also more likely to report improved training to be a facilitator for EMR utilization whereas providers who performed 2 or more EMR per month were more likely to report increased reimbursement as a facilitator for EMR utilization (Figure 2). CONCLUSION: We found that endoscopists identified lack of training to be a major barrier to performing EMR, especially for low-volume providers. Increasing reimbursement and training were important potential facilitators identified in our study. Future quality improvement efforts should target these key practice aspects to optimize the endoscopic management of complex colon lesions.

229 Assessing Varying Techniques of Colonic Endoscopic Mucosal Resection and Subsequent Residual Adenoma at 6-Month Follow-Up

INTRODUCTION: Local recurrence at colonic endoscopic mucosal resection (EMR) sites of medium to large polyps is common at first follow-up (∼10–30%). Extended edge resection has not shown a benefit of reducing this rate; however, edge ablation with snare tip soft coagulation has shown reduced local recurrence. Hybrid argon plasma coagulation (APC) is a novel technique, which can be used to treat microscopic residual disease to prevent local recurrence at follow-up surveillance colonoscopy. This study aims to evaluate if treating both the edges and base of an EMR site with a novel technique, hybrid APC, can reduce the rate of local recurrence at 6-month follow-up versus standard EMR assessing a single endoscopist. METHODS: This is a single center retrospective case series of all colonic EMRs with 6-month surveillance performed by a single endoscopist at a tertiary care center using both standard EMR and hybrid APC assisted EMR from May 2018 to May 2019. The main outcome measure was recurrence of precancerous polyp at prior EMR site at 6-month surveillance colonoscopy. Secondary outcome measures were the rate of procedure associated complications, including post-polypectomy bleeding and post-polypectomy syndrome. RESULTS: A total of 84 EMRs, 38 utilized hAPC, were performed from in the study period. 25 patients (mean age: 65.4 years, 48% men) with 30 polyps were included who completed surveillance colonoscopy after 6 months to evaluate for recurrence (Table 1). The average resected polyp size was 32 mm. Residual polyp recurrence occurred at 4 prior EMR sites (13.3%), with all of the recurrences occurring in patients who underwent standard EMR (100%). There was no recurrence of residual polyps in patients treated with hAPC assisted EMR. Further, 4 patients (15.4%) experienced post-polypectomy bleeding complications within 6 months, with all complications associated with patients treated with standard EMR (Table 2). There was a statistically non-significant trend toward higher recurrence and complication rate in patients treated with standard EMR compared to hAPC assisted EMR. CONCLUSION: In this retrospective study of colonic EMRs, the use of hAPC at initial EMR was associated with decreased local recurrence rate of precancerous tissue at EMR sites and rate of early complications. The findings of this early retrospective study warrant further studies to determine the efficacy of hAPC in reducing the recurrence rate after 6 months and how it compares to standard EMR procedure with snare tip soft coagulation.

2194 Prevention of Excessive Gas Accumulation With a Biliary Dilation Balloon During Endoscopic Cryotherapy

INTRODUCTION: Endoscopic cryotherapy for the treatment of premalignant and malignant conditions has been demonstrated to be an effective tool in esophageal malignancy. However, there is concern for perforation from gas production during cryotherapy. Here we describe the use of a biliary dilation balloon to prevent distal gas accumulation in Roux-en-Y anatomy. CASE DESCRIPTION/METHODS: This is a case of a 77-year-old male with history of total gastrectomy with Roux-en-Y esophagojejunostomy for remote history of gastric leiomyosarcoma and locally advanced esophageal cancer. Two years prior he underwent Endoscopic Submucosal Dissection (ESD) of an esophageal nodule previously biopsied positively for adenocarcinoma. One year ago a surveillance EGD/EUS with biopsy showed no evidence of residual disease at the ESD site. Repeat surveillance EGD/EUS early this year identified thickening of subepithelial layers with a 6mm hypoechoic lesion at the level of the ESD scar. A hybrid ESD and endoscopic mucosal resection (EMR) technique was performed to remove the nodule. Pathology showed invasive poorly differentiated adenocarcinoma with the deeper cauterized margin involved. Endoscopic cryoablation was planned for the remaining margins. Close examination of the ESD defect using EGD and EUS showed no evidence of recurrence. Cryotherapy was then prepared with the insertion of a biliary dilation balloon via a nasal trumpet. The balloon was endoscopically guided to the jejunum distal to the esophagojejunal anastomosis and inflated to prevent distal leakage of cooling gases. A decompression tube was placed in the esophagus proximal to the treatment area. Using the cryocatheter, 3 treatments of liquid nitrogen at -190⁰ C were sprayed over the ESD scar to achieve uniform white frost, each treatment lasting 30 seconds with 60 seconds of defrost time between. Throughout the treatment, suction was provided via the decompression tube and the abdomen was palpated without significant distention. The patient tolerated the procedure well without complication and was discharged home. DISCUSSION: Gas by-products are produced during cryotherapy, which in the case of a patient with a Roux-en-Y, causes substantial risk for perforation. With a distally inflated biliary dilation balloon, gas is prevented from accumulating in the small intestine where it may be difficult to suction, reducing the risk of perforation. This technique may be applied to similar cases where perforation risk is elevated.

3087 Combined Endoscopic and Surgical Management of Small Bowel Polyposis in a Patient With Peutz-Jeghers Syndrome

INTRODUCTION: A 55-year-old male with history of Peutz-Jeghers syndrome was referred for a colonoscopy for management of a large ileal polyp. Surgical history was notable for two laparatomies for small bowel obstructions in the setting of intussusception as well as multiple enterotomies for removal of polyps. CASE DESCRIPTION/METHODS: Colonoscopy confirmed a polypoid mass in the distal ileum that was partially obstructing. Endoscopic submucosal dissection of the polyp stalk was performed but revealed two feeding arteries as well as a thick muscular band, concerning for muscularis propria, that precluded further safe dissection. Hemoclips were placed on the feeding arteries in an attempt to cause necrosis of the lesion. After discharge the patient developed hematochezia. Repeat colonoscopy did not show any ongoing bleeding but the mass appeared to be necrotic. Repeat colonoscopy was planned in the operating room to evaluate the mass. If the necrosis was not complete, dissection of the stalk would be re-attempted with plans to convert to surgical resection if needed. On endoscopy, the mass appeared to have revitalized. Another attempt at submucosal dissection of the polyp stalk was performed. However as the area had already been dissected through, the submucosal plane was not easily identified in the stalk and did not feel that it was safe to continue the submucosal dissection. Subsequently, the patient was converted to surgical resection of the ileal polyp, which also revealed multiple polyps more proximally throughout the small bowel. The bowel resection included the initial large polyp and another large polyp at a prior ileal anastomosis that could not be removed without a resection. Multiple other polyps were removed via enterotomies. To clear the remaining small bowel of residual polyps, we performed a clean sweep. A pediatric colonoscope was introduced orally and the scope was able to be advanced distally to the ileal anastomosis by plicating the bowel over the scope. Multiple further polypectomies were then performed using standard endoscopic mucosal resection technique. On 3 month follow up MR enterography, there were no convincing polyps identified in the entire small bowel. DISCUSSION: This case demonstrates the importance of a multi-disciplinary approach to the management of this patient's polyposis. The combination of endoscopic and surgical approach allowed for effective management of both the large ileal polyp as well as his overall polyp burden. Watch the video: http://bit.ly/2JWHRA2

866 Safety and Efficacy of the Novel Endorotor® Mucosal Resection System: First Multicenter USA Experience

INTRODUCTION: The EndoRotor® (ER) non-thermal tissue resection device (Interscope Inc., USA) is a novel mechanical endoscopic resection system developed for use in the gastrointestinal tract for removal of neoplastic or pre-neoplastic tissue. It utilizes adjustable suction and a rotary cutting blade to precisely resect mucosal and submucosal tissue. Our aim was to assess the technical feasibility, safety and efficacy of endoscopic mucosal resection (EMR) using the ER device. METHODS: This was an IRB-approved multicenter retrospective review of prospectively collected data of patients that underwent EMR with ER device from 11/2018 to 06/2019 at 4 high-volume US centers. Patient-specific data were collected including demographics and indication for EMR. Procedural and histopathological data were also obtained. RESULTS: During the study period, 35 patients underwent EMR with ER of 42 lesions. Patient characteristics described in Table 1. Most common indications for EMR were colon polyps (n = 15, 42.9%) and Barrett’s Esophagus (n = 10; 28.6%). Most (n = 25; 71.4%) patients had a prior resection attempt for the same indication using standard techniques; ER-EMR was successful in all these difficult cases. The majority (n = 32; 91.4%) had a single lesion resected; 3 patients had multiple lesions resected in same session. ER-EMR was technically feasible in all patients, with complete resection achieved in 33 (94.3%) patients (Table 2). Mean lesion size was 2.1 cm (range = 0.35–4 cm). Most frequent histopathological findings in the colon were tubular adenoma (n = 10; 45.5%) or sessile serrated adenoma (n = 5; 22.7%). Most common esophageal pathology in BE patients was high-grade dysplasia (n = 5; 50%). Intra-procedural bleeding was observed in 9 (25.7%) patients, all managed endoscopically. No ER-related perforation occurred. Post-procedural complications were reported in 7 patients (20%), including self-limited chest pain (n = 1), mild stenosis (n = 3), and delayed bleeding (n = 3). Of patients that have undergone a follow-up endoscopy (n = 13; 37.1%), no residual lesion was seen in majority (n = 10; 76.9%). CONCLUSION: The Endorotor® device is a novel, effective and safe non-thermal EMR technique that allows efficient endoscopic resection of flat and polypoid lesions, especially those with submucosal scarring. Our initial experience suggests it has a promising role in the endoscopic management of both naïve and difficult to remove luminal lesions in the foregut and in the colon.

A novel non-thermal resection tool in endoscopic management of scarred polyps.

Background and study aims Scarred polyps are challenging to resect using conventional endoscopic mucosal resection (EMR) techniques. The aim of this pilot study was to assess the feasibility of the EndoRotor device in resecting scarred polyps arising from previous endoscopic resection attempts. Patients and methods This was a prospective pilot study of patients with scarred colonic polyps treated using EndoRotor carried out in two centers. Results A total of 19 patients were included in this study. The overall cure rate using EndoRotor was 84 %; 10 patients (52.6 %) achieved cure after one attempt and six patients (31.5 %) achieved cure after two attempts. A total of three patients who had polyp recurrence after the first EndoRotor resection were referred for either endoscopic submucosal dissection (2 patients) or surgery (1 patient) due to difficult access. There were no perforations, delayed bleeding, post-polypectomy syndrome or complications requiring surgery. Conclusions In this pilot study, the novel non-thermal device (EndoRotor) has been demonstrated to be a safe and effective technique in challenging management of scarred polyps. Further randomized controlled trials comparing this technique with APC, hot avulsion, ESD and endoscopic full-thickness resection are required to ascertain the utility of EndoRotor in the hands of non-expert endoscopists.

Mo1226 THE EFFECT OF ENDOSCOPIC MUCOSAL RESECTION (EMR) VS ENDOSCOPIC SUBMUCOSAL DISSECTION (ESD) TECHNIQUE ON HISTOLOGIC MARGINS FOR ENDOSCOPICALLY TREATED EARLY ESOPHAGEAL ADENOCARCINOMA

Both endoscopic mucosal resection (EMR) and endoscopic submucosal dissection (ESD) techniques are used for the treatment of early esophageal cancers. ESD has potential advantages including higher en bloc and R0 resection rates, which have been demonstrated for squamous cell carcinomas (ESCC) but data for esophageal adenocarcinoma (EAC) is more limited. Histologic determination of the horizontal and vertical margins is important to determine the completeness of resection and risk of recurrence. Larger tumors, especially those that spread laterally may exceed with limits of en bloc resectability using standard EMR techniques.

Endoscopic Submucosal Dissection for Colitis-Associated Dysplasia.

Dysplasia is a precancerous lesion of colorectal cancer in patients with long-standing inflammatory bowel diseases (IBDs), such as ulcerative colitis and Crohn’s disease. Recent guidelines suggest endoscopic resection as a key modality for the treatment of endoscopically resectable dysplasia in patients with colitis. Endoscopic submucosal dissection (ESD) has been suggested as one of the therapeutic options for dysplasia that is potentially resectable but not suitable for the conventional endoscopic mucosal resection technique. Several recent studies supported the feasibility of ESD for the treatment of colitis-associated dysplasia in terms of the en bloc and complete resection rates and the risk of procedure-related complications. However, these studies were performed exclusively in expert centers. Moreover, the local and metachronous recurrence rates were relatively high, and long-term outcome data are still lacking. Endoscopists should be highly skilled in colorectal ESD and have an intensive understanding of not only the lesions but also the conditions of patients with IBDs. Therefore, the decision to perform ESD for colitis-associated dysplasia should be made scrupulously after careful discussion with patients, in collaboration with a multidisciplinary IBD team including physicians, surgeons, and pathologists specialized in IBDs.

Solutions for submucosal injection: What to choose and how to do it.

During the past decades, endoscopic resection techniques have gradually improved and gained more importance for the management of premalignant lesions and early cancers. These endoscopic resection techniques can be divided in 3 major groups: snare polipectomy, endoscopic mucosal resection (EMR) and endoscopic submucosal dissection (ESD). The use of submucosal injection is essential for the majority of EMR techniques and is an integral part of ESD, whereas during polipectomy it is not crucial in most cases except to prevent bleeding in large polyps and/or those with large stalks as an alternative to mechanical methods. Injection provides a lifting up effect of the lesion separating it from the muscular layer, thereby reducing thermal injury and the risk of perforation and bleeding while also facilitating en-bloc resection by improving technical feasibility. With this work, we aim to review the most common endoscopic resection techniques and the importance of submucosal injection in each one of them. For that, we present some of the most commonly used submucosal injection solutions, taking into account their advantages and disadvantages. We also discuss, based on current recommendations and our own experience, how and when to preform submucosal injection, depending on lesions features and endoscopic resection technique that´s being used, to assure complete resection and to prevent associated adverse events. Finally, we also present and discuss some new proposed submucosal injection solutions, endoscopic resection techniques and devices that may have a major impact on the future of therapeutic endoscopy.

A Case of Endoscopic Mucosal Resection of Gastric Metastasis From Renal Cell Carcinoma Without Recurrence

IntroductionRenal cell carcinoma (RCC) with gastric metastasis is extremely rare. The most common intervention is partial gastric resection; however, recently interventions including endoscopic submucosal dissection (ESD) and endoscopic mucosal resection (EMR) have been used. We present a case of gastric metastasis from RCC that was completely resected by EMR with pathology showing clear margins. Two year follow up showed no local recurrence or distal metastasis. Case Report A 86-year-old male with history of RCC PT2N0M0 diagnosed 8 years prior s/p partial right nephrectomy presented to the ED with exertional dyspnea. Patient had a hemoglobin of 7mg/dL. Emergent EGD revealed a single 25mm sessile polyp in the gastric fundus with stigmata of recent bleeding treated with epinephrine injection. Subsequently patient underwent repeat EGD and, in view of atypical nature, polyp biopsies were performed. Pathology showed inflammatory changes and no malignancy. Five days later, the patient underwent repeat EGD. The polyp was excised completely by standard EMR technique with methylene blue saline-lift. Pathology of the polyp showed metastatic clear cell renal carcinoma with clear cauterized margin. Follow-up EGDs performed at 10 days, 4, 9 and 22 months and EUS at 9 and 24 months post EMR showed no local recurrence. PET/CT at 15 and 24 months after EMR revealed no evidence of distal metastases. Discussion In a known RCC with gastric metastasis, EUS should be performed to evaluate the involvement of gastric layers. If the fourth layer (muscularis propria) is involved, partial gastrectomy is the preferred choice. Otherwise an ESD with en bloc excision is the best option. In our case, the initial biopsy report was negative for malignancy; therefore, an EMR was done. The polyp could be lifted well with injection of methylene blue saline (lift sign is the best marker that could be used for assessing excision of lesion by EMR) hence the polyp was resected completely with negative cauterized margins. Our close surveillance in the span of 2 years with no recurrence, makes our case of a gastric metastasis resected by EMR an effective endoscopic intervention.2127_A Figure 1. (A) A single 25 mm sessile polyp with stigmata of recent bleeding was found in the gastric fundus. (B) An EGD 5 days later showing 25 mm sessile polyp found on prior endoscopy (C) EGD s/p polypectomy via an EMR with complete resection and retrieval.2127_B Figure 2. (A) This is a H&E slide with 10x magnification. Superficial biopsy showing inflammatory changes, and granulation tissue. (B) H&E slide with 2X magnification showing metastatic RCC with well visualized cauterized resection with clear margins. Cauterized margin (blue arrows) is 1.5 mm away from closest metastatic RCC (asterisks). (C) H&E slide of the RCC with 10x magnification. (D) H&E slide with 40x magnification of RCC.2127_C Figure 3. Two year follow up EUS shows endoclip in the gastric fundus with intact fourth layer (muscularis propria) and no subepithelial lesion.

Mo1151 EFFECT OF ENDOSCOPIST FATIGUE IN RELATION TO ENDOSCOPIC MUCOSAL RESECTION OF LARGE COLON POLYPS

Endoscopic mucosal resection (EMR) of large colon polyps is technically challenging and therefore often performed by endoscopists with significant experience in this procedure. It is not known if endoscopist fatigue influences the success of colon EMR for large colon polyps. The primary objective of our study is to assess whether procedural success of colon EMR is affected by endoscopist fatigue or time of day when colon EMR is performed. We conducted a retrospective review of all colon EMR procedures performed by four therapeutic endoscopists at two academic tertiary care hospitals between 1/1/2015 – 12/31/2016. Patients included for this review had colon polyps > 20 mm that were removed with injection-lift EMR technique. Technical success was defined as endoscopist assessment of complete resection of the polyp. All patients for whom follow-up information was available were assessed for residual neoplasia on follow-up colonoscopy. We assessed whether endoscopist fatigue as measured by: afternoon versus morning, number of endoscopic procedures performed before the procedure under consideration, including adjustment for procedure complexity and the total procedure related RVUs had an impact on the technical success of the procedure or the rate of residual neoplasia. In order to examine these fatigue measures we stratified the cases under review into quartiles. Quartile 1 represents the colon EMR cases with fewest preceding cases, while quartile 4 represents colon EMR cases with the largest number of preceding cases. A total of 154 patients underwent colonoscopy to resect 170 large colon polyps by EMR technique. Overall, 87.7% of the lesions were removed successfully. 21 lesions could not be removed endoscopically. Follow-up information was available for 68.3% of patients. 28 patients underwent surgery (14 for invasive carcinoma, 3 for high grade dysplasia, 11 for unresectable lesions). Of 75 patients who underwent successful colon EMR and had follow-up colonoscopy, 80% had no evidence of residual neoplasia. When assessing endoscopist fatigue by total number of procedures, number of procedures adjusted for complexity and total procedure-related RVUs prior to performing colon EMR, no effect was found in relation to technical success or rates of residual neoplasia on follow-up. There appeared to be a trend towards lower rate of technical success and a higher rate of residual neoplasia for colon EMR procedures performed in the afternoon versus the morning, however this difference was not statistically significant. We conducted similar analysis for each endoscopist individually with the same findings. Endoscopist fatigue did not have a significant effect on the technical success of colon EMR, nor did it adversely impact the rate of residual neoplasia on follow-up colonoscopy.Tabled 1Association between endoscopist fatigue and colon EMR outcome measuresFatigue measureTechnical successResidual neoplasia rateStart timeMorning exam89.5% (referant)20.4% (referent)Afternoon exam83.0% (p=0.25)34.8% (p=0.18)Raw fatigue scoreQuartile 192.7% (referent)25.0% (referent)Quartile 284.4% (p = 0.27)32.1% (p=0.62)Quartile 381.6% (p= 0.14)30.8% (p=0.73)Quartile 490.2% (p=0.69)15.8 % (p=0.50)Consensus fatigue scoreQuartile 192.7% (referent)25.0% (referent)Quartile 281.6% (p=0.15)26.3% (p=0.93)Quartile 382.5% (p =0.18)30.0% (p=0.74)Quartile 490.9% (p=0.77)13.6% (p=0.38)RVU fatigue scoreQuartile 192.7% (referent)25.0% (referent)Quartile 280.5% (p=0.12)26.3% (p=0.93)Quartile 380.5% (p=0.12)36.8% (p=0.43)Quartile 495.0% (p=0.67)15.8% (p=0.48) Open table in a new tab

863 UNDERWATER EMR (UEMR) OF LATERALLY SPREADING TUMORS INVOLVING THE ILEOCECAL VALVE

Laterally spreading tumors (LSTs) involving the ileocecal valve (ICV) are often referred to surgery due to a higher risk of perforation or incomplete resection using conventional endoscopic mucosal resection (EMR) technique. We hypothesized that the "floating" effect of water on the IC valve, which has a high fat content, may facilitate EMR. Evaluate the feasibility, safety, and efficacy of UEMR without submucosal injection for the treatment of LSTs involving the ICV. Prospective, observational study using a standardized UEMR technique without prior submucosal injection. Patients scheduled for surveillance colonoscopy with biopsies at 6 months. Primary endpoints: Complete resection at index procedure and residual or recurrence at follow up. Secondary endpoint: Complications, including: immediate (up to 24h) bleeding, delayed (>24h) bleeding, perforation, and abdominal pain. Over 77 months, 102 consecutive patients (54% female, mean age 67) underwent attempted resection of LSTs at the ICV by UEMR. All had undergone prior colonoscopy elsewhere and 15 (15%) had been referred for surgical treatment. A previous unsuccessful attempt at resection had been performed in 20 patients (20%). Mean LST size was 29 mm (5 LSTs < 15 mm). UEMR was successful in 100 patients (98%), of whom 23 (23%) had en bloc resections. Mean total procedure time was 46 min and mean resection time was 14 min. Two patients had unsuccessful resections and were referred to surgery. Delayed bleeding occurred in 8 patients (8%), 7 of whom went to the ER, and 3 of whom were hospitalized (2 transfused, one sent for hemicolectomy). No perforations occurred, and no abdominal pain was reported. Final pathology: tubular adenoma (47), villous or tubulovillous adenoma (41), serrated adenomas (8), invasive adenocarcinoma (3), hyperplastic polyp (1), inflammatory polyp (1), and non-diagnostic tissue (1). Of 72 patients (71%) who completed surveillance residual adenoma was found in 2 (3%) patients on their first follow up colonoscopy and retreated by UEMR; one has been free of recurrence on third follow-up colonoscopy and one was lost to follow-up. In this large patient cohort, UEMR was found to enable successful and safe resection of LSTs involving the ICV with nearly no residual or recurrence observed in patients who completed surveillance. Water submersion may also protect against perforation. Further study is warranted.

Perspectives on endoscopic submucosal dissection training in the United States: a survey analysis.

Background and study aims Endoscopic submucosal dissection (ESD) is a widely accepted method for en-bloc resection of dysplastic lesions and early cancer in Asia and Europe. A limiting factor in adoption of ESD in the United States is perceived lack of training opportunities. The aims of this study were to: (1) evaluate ESD experience of attendees at a University-sponsored ESD training course; (2) characterize effectiveness of the current ESD training regimen and its impact on ESD adoption in the United States; and (3) gauge trainees’ attitude towards ESD. Patients and methods An electronic anonymous survey was distributed to the 86 physicians who participated in the University of Florida’s annual ESD course from 2014 to 2016. Main outcomes included participants’ practice setting, prior training, current ESD techniques, and planned training. Results A total of 34 participants (40 %) completed the survey. Most of the respondents routinely use one or more endoscopic mucosal resection (EMR) techniques (97.1 %) in their practice. Most respondents (79 %) had no experience with ESD on humans prior to the ESD course. Following completion of course training, more participants reported ongoing hands-on ESD exposure, with 15/34 (44 %) having performed ESD in humans. Most participants identified potential hurdles for adoption of ESD. Conclusion A dedicated ESD training course with hands-on experience, under the guidance of experts, notably increased use of ESD among participants. Limited availability of structured training opportunities, concerns over procedural length, lack of adequate number of lesions, and potential for serious adverse events (AEs) were identified as the main factors slowing adoption of ESD in the United States.

A novel triple-anchoring technique for hybrid endoscopic mucosal resection.

A novel triple-anchoring technique for hybrid endoscopic mucosal resection.

Low Grade Pre-malignant Lesion of Pancreatic Rest in Stomach, Surveillance a Dilemma

INTRODUCTION: Pancreatic intraepithelial lesions (PanIN) are premalignant lesions of pancreatic ductal adenocarcinoma (PDA). PanIN and PDA found in ectopic gastric pancreatic rest tissue are extremely rare, with only two cases of low-grade PanIN in ectopic gastric ectopic pancreatic tissue reported. In this case report, we present a case of PanIN in gastric ectopic pancreatic tissue found after lesion removal by endoscopic mucosal resection (EMR). CASE REPORT: A 47-year-old female with no significant history underwent an upper endoscopy for abdominal pain. Upper endoscopy revealed gastritis in the stomach and a 1 cm subepithelial lesion with central umbilication in the gastric antrum (figure 1). Endoscopic ultrasound examination revealed that the lesion was arising and limited to only the submucosa. EMR was performed to remove the lesion en bloc (figure 1). Pathological examination revealed gastric heterotopic pancreatic tissue and focal pancreatic intraepithelial neoplasia 1A (figure 2). Follow-up surveillance endoscopy performed at 6 months revealed no evidence of recurrence (figure 3).Figure: Endoscopic image showing (Left) A 1 cm submucosal polyp with central umbilication in the antrum. (Middle) Post en-block removal of polyp by endoscopic mucosal resection technique. (Right) Lesion closed with 2 clips.Figure: Histopathologic examination of haematoxylin and eosin stained pancreatic rest tissue specimen under x400 shows that pancreatic duct is lined by a single layer of epithelium with abundant apical mucinous cytoplasm and basal nuclei that lack atypia consistent with Pancreatic Intraepithelial Neoplasia 1A.Figure: Endoscopic image showing a scar tissue in the antrum from prior intervention with no residual pancreatic rest tissue.DISCUSSION: PanIN refers to a small intraductal noninvasive lesion formed by metaplasia and proliferation of ductal epithelium. It is classified by dysplasia severity—PanIN 1 and 2 are low grade, and PanIN 3 is high grade. In orthotopic pancreas, PanIN 3 is known as carcinoma-in-situ. Conversely, PanIN 1 and 2 tumors grow slowly, might take up to 12 years to transition into PanIN 3 and even longer to change to PDA. These results can be extrapolated to pancreatic rest tissue due to similar mutations. Presently, asymptomatic pancreatic rest is monitored, while symptomatic cases—or those suspicious of malignancy on ultrasound—are resected using endoscopic techniques or surgical resection. There are no guidelines for endoscopic surveillance and therapy of these asymptomatic, premalignant and malignant gastric ectopic pancreatic rest lesions. In this case we highlight a very rare incidence of a low-grade premalignant lesion within gastric ectopic pancreatic rest removed by endoscopic resection. Further research is necessary to better define strategies for endoscopic surveillance and therapy of asymptomatic gastric ectopic pancreatic rest given the potentiality of these lesions to be premalignant and transform into malignant lesions that carry a poor prognosis.

Efficacy of Cap-assisted Endoscopic Mucosal Resection of Ileocecal Valve Polyps

Introduction: Standard endoscopic mucosal resection (EMR) of ileocecal valve polyps is limited. Capassisted endoscopic mucosal resection (C-EMR) is a technique that can be performed when polyps are not easily amenable to standard EMR. Current literature is limited regarding its efficacy and safety for ileocecal valve polyps. We have successfully used C-EMR in an effort to treat these polyps endoscopically. The objective of this study was to formally assess the efficacy and safety of C-EMR for ileocecal valve polyps. Methods: A retrospective review was conducted from September 2008 to November 2016 at a tertiary care center. Patients included in the study underwent C-EMR for ileocecal valve polyps by a single gastroenterologist. Polyps were considered successfully eradicated if they were removed en-bloc as confirmed by pathology, or had a negative biopsy on follow-up colonoscopy. Outcomes of the procedures were evaluated, including eradication rate, complications rate, and rate of hospitalizations due to procedure related complications. Results: A total of 14 C-EMRs were performed. Median polyp size was 1.5cm (Interquartile range, IQR, 1.5, 2) with sessile or flat characteristics. Pathology revealed 11/14 (78%) were adenomas, 1/14 (7%) adenocarcinoma, 1/14 (7%) serrated, and 1/14 (7%) inflammatory. Median follow up time was 4 (3, 6.25) months. Two patients were lost to follow-up. Among the patients with available short follow-up, the overall eradication rate was 100% (12/12). Two patients were hospitalized. First was for concern for deep mucosal resection, treated at the time of endoscopy with 2 clips. He was asymptomatic post procedure with negative abdominal X-ray, and discharged the next day. The second patient had pain post polypectomy. CT of the abdomen was negative for perforation. He responded to conservative management and discharged two days later. Two patients have had subsequent surveillance colonoscopies at 8 and 56 months without recurrence. One patient had surveillance colonoscopy at 67 months, which showed a 6mm flat polyp at the edge of the previous scar, concerning for residual adenoma or a new polyp. The polyp was subsequently treated with C-EMR and repeat colonoscopy 6 months later showed no recurrence. Conclusion: C-EMR is highly effective in treating ileocecal valve polyps with a low complication rate. C-EMR is our suggested method in approaching ileocecal valve polyps that are difficult to remove via standard free hand snare EMR technique.

Endoscopic mucosal ablation and resection of Barrett's esophagus and related diseases.

The prevalence of gastroesophageal reflux disease as well as the incidence of Barrett's esophagus (BE) has increased in the Western world over the last decades. The chronic reflux of gastric secretions injuries the esophageal mucosa and triggers cellular and molecular changes inducing the transformation of the normal squamous mucosa into columnar metaplastic epithelium. BE is a premalignant condition that can progress to low-grade dysplasia, high-grade dysplasia and ultimately esophageal adenocarcinoma. An early diagnosis of dysplastic changes and the adoption of appropriate therapeutic approaches are essential to improve patient outcomes and survival. Endoscopic therapies such as radiofrequency ablation (RFA) and endoscopic mucosal resection (EMR) have been developed to treat dysplastic changes and mucosal abnormalities suspicious of malignancy. RFA has shown to be safe and effective for the treatment of low and high-grade dysplasia. EMR is diagnostic for mucosal lesions and potentially therapeutic for high-grade dysplasia or intramucosal adenocarcinoma. Proficient endoscopic skills and frequent practice are essential elements for a successful result. Here, we describe patient selection, the pre- and post-operative management, and the surgical technique for RFA and EMR in patients with the diagnosis of dysplastic BE and intramucosal esophageal adenocarcinoma.