400 Utility of the Over-the-Scope-Clip As Endoscopic Monotherapy for Severe Acute Upper, Middle and Lower Gastrointestinal Bleeding

Abstracts

397 Anterior vs Posterior PerOral Endoscopic Myotomy (POEM): Is There a Difference in Outcomes? Stavros N. Stavropoulos*, Rani J. Modayil, Collin Brathwaite, Bhawna Halwan, Maria M. Kollarus, Sharon I. Taylor, David Friedel, James H. Grendell Medicine, Winthrop University Hospital, Mineola, NY Background: Unlike Laparoscopic myotomy, POEM affords freedom in selecting the myotomy orientation with some centers favoring anterior (A) and some posterior (P) orientation. It has been postulated that posterior POEM by cutting the sling fibers of the LES that maintain the angle of His (rather than the shorter clasp fibers cut in anterior POEM), may result in a more patulous LES with greater relief of dysphagia at the expense of more reflux. Some have also postulated that posterior POEM can be performed more rapidly and easily due to the location of the incision along the axis of the therapeutic channel of the endoscope. Finally, some authorities have suggested that in anterior POEM there may be more dense vascularity in the cardia and higher risk of intraprocedural hemorrhage as well as more escape of CO2 that may increase the incidence of capnoperitoneum/capnothorax. No data exist to date in support of any of these contentions. Aim: To assess outcomes in anterior vs posterior POEM in our single operator series of 248 POEMs (120 A, 128 P) performed from 10/2009 to 10/2015. Results: No learning curve bias expected as we performed a similar percentage of anterior POEMs in the first 3 years of our series (48/ 91, 53%), as in the last 2 years (vs 72/157 46%). Data were analyzed from a prospectively maintained database. There were no difference in the Eckardt score, including failures (post POEM Eckardt score>3, 5/110 AP vs 4/117 P, NS)., accidental mucosal injuriesincluding non-transmural minor blanching (29% vs 23%), prolonged stay of >5 days (1/ 119 A, 1/128 P). There was no difference in significant AEs but it should be noted that there was paucity of such events in our series with no leaks, no tunnel bleeds and no surgical/IR interventions. Posterior POEM was significantly faster overall (97 min A, 79 min P, PZ0.0007) including a faster closure (Suturing 177, clips 71) (9.6 min A, 7.9 min P, PZ0.02). More pts had pain requiring narcotics in posterior POEM (17% A vs 27% P, PZ0.007). There was a trend for less acid reflux in anterior POEM: +BRAVO studies (21/58 A, 29/58, PZ0.13), reflux esophagitis (22/57A, 33/60 P, PZ0.076). Based on these results we calculated a sample size of 120 (including 20% dropout) for an Anterior vs Posterior randomized trial to demonstrate that posterior POEM is faster. However, a larger number may be required to demonstrate a difference in incidence of reflux at 95% confidence. We have currently enrolled 94 pts in this RCT to be reported separately. Conclusion: Based on our analysis of our 248 single operator POEM series, anterior POEM is slower but results in less pain and less acid exposure and reflux esophagitis (90% confidence level). We are close to completing enrollment in a single operator anterior/posterior randomized trial.

398 Metabolic Effect in a New Experimental Model of Gastric Bypass Using Luminal Apposing Stent and Surgical Endoscopy Geoffroy Vanbiervliet*1, Patricia Ancel2, Mourad Boufi3, Laurie Bruzzese2, Jean-Michel Gonzalez3, Emmanuelle Garnier2, Marie-Christine Saint-Paul4, Marie-Christine Alessi2, Stéphane Berdah3, Anne Dutour3, Marc Barthet3 1 Digestive Endoscopy, Hôpital L’Archet 2, Nice, France; 2Aix Marseille University, Marseille, France; 3Assistance Publique des Hôpitaux de Marseille, Marseille, France; 4Hôpital Pasteur - CHU, Nice, France Introduction: Gastrojejunal anastomosis (GJA) using exclusive NOTES technique and luminal apposing stenting (LAS) appears safe and effective in both experimental model and humans. The purpose of this study was to determine the metabolic effects of a new endoscopic bypass gastric experimental model. Material and Methods: This was a prospective experimental animal study conducted at the Aix Marseille University from Jan 2014 to Aug 2015. Procedures were carried out on non-obese domestic pigs of 20 to 30 kg under general anesthesia. GJA at 150 cm from the duodeno-jejunal angle was performed by an LAS technique (Hot AxiosÒ, Boston Scientific Corp., Natick, USA) using a dual working channel gastroscope as previously described by our team. Surgical duodenal exclusion was randomly done during a short laparotomy using a stapler. Metabolic tests were pre (D0) and postoperatively (D14/D21) performed in all animals to assess glycemic responses, insulin, GLP-1, PYY, ghrelin, CRP, IL-6, TNF-a, leptin and adiponectin over 2 hours after a standard meal test (primary endpoint). After 3 weeks of monitoring, the stent was randomly removed by endoscopy. Animals were euthanized at D42. The permeability of the anastomosis was confirmed by endoscopy and a final histological analysis (secondary endpoints). Results: The procedure was successfully performed in all included pigs (n Z 10, average weight: 19.96  1.9 kg [17.5 to 23.7]) with an average total duration of 41.3  3.8 minutes (30-50) including a mean endoscopic time of 20.4  4.6 minutes (10-26). A significant reduction of the mean area under the curve for blood glucose at D14 (p Z 0.0039) and D21 (p Z 0.0156), and for insulin (p Z 0.0391) on day 21 was observed. The ratio glucose / insulin was significantly increased on day 21 (p Z 0.0039). No significant GLP-1 and peptide YY variation were observed as for the inflammatory proteins, leptin or adiponectin. The fasting ghrelin levels were significantly reduced on day 14 (p Z 0.0199) and D21 (p Z 0.0214). The duodenal exclusion in 4 pigs did not involve significant changes in metabolic results. Three pigs died during follow-up, 2 of unrelated causes to the procedure. At the end of follow-up, the diameter of the gastrointestinal anastomosis

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was significantly decreased in pigs randomly assigned to early stent removal at 3 weeks (p Z 0.0159), with stricture for 4 of the 5 pigs concerned, responsible for death in one case. A fusion of muscular layer was most frequently observed during histological analysis in the case of late conservation of the stent up to D42 (p Z 0.0476). Conclusion: The experimental gastric bypass model proposed with gastrointestinal anastomosis using LAS in non obese pig induced significant changes in glycemic metabolism suggesting decrease in insulin resistance associated with a decrease in fasting ghrelin, independently of duodenal exclusion.

399 A New Procedureless Intragastric Balloon Capsule for Bariatric Therapy Hidetoshi Ohta*1,2, Tamotsu Sagawa3, Shinichi Katsuki4 1 Gastroenterology, Sapporo Orthopedics and Cardiovascular Hospital, Sapporo, Japan; 2Gastroenterology, Shiroishi Memorial Hospital, Sapporo, Japan; 3Gastroenterology, Sapporo National Organization Hokkaido Cancer Center, Sapporo, Japan; 4Center of Gastroenterology, Otaru Ekisaikai Hospital, Otaru, Japan Introduction: Obesity and diabetes are urgent worldwide health problems. In the USA, two thirds of people over sixty are estimated to be suffering from obesity and only 1% of them underwent bariatric surgery. Instead of invasive bariatric surgery, minimally invasive methods are being seen as more acceptable alternatives, particularly for some patients. New innovative methods include the intragastric balloon with endoscopic support presented by Abu Dayyeh at DDW2015 and the gastric balloon pill (ElipseTM balloonÒ) with the thin inflation tube, which was recently unveiled by Ram Chuttani (Obesity Week. 2015). We present a prototype of a non-invasive intragastric balloon capsule without any endoscopic procedure. Materials and methods: The capsule consisted of a gelatin housing which enclosed a magnetic valve, dry ice rod, bio-soluble plug and silicone balloons. This first prototype of the balloon capsule was tested in a phantom filled with warm water. CO2produced from the sublimation of the dry ice inflated the balloons. After confirming the arrival of the capsule in the stomach of the phantom magnetically (using equipment from our capsule navigation system, DDW2013 and 2015), an extracorporeal magnet was used to navigate it to the optimal position. After the bio-soluble plug had dissolved, the balloon was deflated by using the extracorporeal magnet to open the magnetic valve. We confirmed endoscopically that the deflated balloon was small enough to be excreted. In a separate experiment, we timed how long the balloons remained fully inflated in dilute acid with only a biosoluble plug to stop the CO2 escaping. In addition, an endoscope was used to see how quickly the silicone balloon could be retrieved in an emergency. Results: 1) The maximum volume of the silicone balloons was 550ml, 2) The volume of CO2 was in proportion to the volume of dry ice, theoretically 750 times. 3) It took nearly 2 minutes for the balloons to be inflated perfectly inside the phantom. 4) The 1.5 Tesla extracorporeal magnetic paddle could control the magnetic valve and deflate the balloons. 5)The self-deflating balloons with only the bio-soluble plug remained fully inflated in the acid for about 3 months. 6) It took five minutes to retrieve the balloon using an endoscope. Conclusion: The test in the phantom went well, so we are planning further tests including in vivo tests to validate the usefulness of this non-invasive and procedureless balloon capsule for reducing weight.

400 Utility of the Over-the-Scope-Clip As Endoscopic Monotherapy for Severe Acute Upper, Middle and Lower Gastrointestinal Bleeding Paul T. Kroner*, Juan P. Gutierrez, Ujjwal Kumar, Kondal R. Kyanam Kabir Baig, Ivan Jovanovic, Klaus Monkemuller University of Alabama At Birmingham, Birmingham, AL Background: The over-the-scope-clip (OTSC) has proven useful for sealing various types of defects of the gastrointestinal (GI) tract. Initial reports proved its benefit as a rescue therapy. Due to its special configuration and easiness o deployment the OTSC system is now being used as initial hemostatic therapy in GI bleeding. Aim: To evaluate the usefulness and safety of OTSC for primary endoscopic hemostasis as mono-therapy in patients presenting with severe hemorrhage involving the upper, middle and lower GI tract. Methods: Observational, open-label, retrospective, singlearm, consecutive study cohort conducted at one tertiary care center. The OTSCsystem was loaded on the scope and the lesion was suctioned into the transparent cap before releasing the clip. Clips with a 220 cm long string were used for small bowel and colonic bleeding cases. No additional devices such as grasping forceps were used. Data analysis included primary hemostasis, complications, and 3-month follow-up clinical outcome. Results: During a 2-year-period, a total of 41 clips were applied in 37 patients (23 male, 14 female, mean age 59.2 years, range 24-89. All patients had received blood transfusions; mean 2 units of packed red blood cells, range 2-32. The etiology of bleeding was: gastric ulcer nZ12, duodenal ulcer nZ8 (all Forrest 1a or b), actively bleeding Dieulafoy nZ5, jejunal anastomotic ulcer in Roux-en-Y gastric bypass or jejuno-jejunal anastomosis with bleeding nZ6, anastomotic varices nZ1, actively bleeding Mallory-Weiss tear nZ2, colonic ulcer with bleeding n Z 2, colonic Dieulafoy nZ1. Immediate hemostasis (technical success) was achieved in 100%. Re-bleeding occurred in two patients (5.4%, one gigantic ischemic anastomotic ulcer requiring four clips and one large Mallory-Weiss tear requiring two clips). The majority of clips (56%) were applied by GI fellows-intraining, supervised by therapeutic endoscopists (KM, KK). There were no adverse

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Abstracts

associated with OTSC-applications. Conclusions: This is the one of the largest single center experiences using OTSC as endoscopic mono-therapy for severe GI bleeding of originating in the upper, middle and lower GI tract. Whereas previous data has emphasized that OTSC is effective as rescue therapy our data supports it use as mono-therapy. The use of OTSC was effective, efficient, easy and safe. This device should be added to the endoscopy-bleeding cart.

401 Low Prevalence of Advanced Histological Features in Diminutive Colon Polyps: Results From a Prospective Multicenter Study Evaluating Real-Time Characterization of Diminutive Colorectal Polyp Histology Using Narrow Band Imaging (NBI) Swati G. Patel*1,2, Philip Schoenfeld3, Ajay Bansal4, Lindsay Hosford1, Aimee Myers3, Robert H. Wilson1, Jenna Craft5, Dennis Ahnen6,1, Amit Rastogi4, Sachin Wani1 1 Internal Medicine, Division of Gastroenterology and Hepatology, University of Colorado, Aurora, CO; 2Internal Medicine, Division of Gastroenterology and Hepatology, Veterans Affairs Hospital, Denver, CO; 3Internal Medicine, Division of Gastroenterology and Hepatology, University of Michigan, Ann Arbor, MI; 4Internal Medicine, Division of Gastroenterology and Hepatology, University of Kansas Medical Center, Kansas City, MO; 5Northwestern University, Chicago, IL; 6 Gastroenterology of the Rockies, Boulder, CO Background: Real-time characterization of diminutive colorectal polyp ( 5mm) histology has been shown to be accurate using NBI. A ‘characterize, resect and discard’ strategy for diminutive polyps has been proposed that could result in substantial cost savings by decreasing cost of histopathology. However, a high prevalence of advanced histology (villous histology, high-grade dysplasia and/or cancer) in diminutive polyps may deter adoption of this strategy. Aim: To determine the prevalence of advanced histological features in diminutive (1-5mm) colorectal polyps compared to small (6-9 mm) and large ( 10 mm) polyps. Methods: Endoscopists at two tertiary academic centers underwent standardized training on NBI characterization of polyp histology and subsequently made real-time predictions of diminutive polyp histology during routine colonoscopies. Polyp size was estimated using standard references (snare catheter size, biopsy forceps size). Polyp size, location and histology were recorded. Each polyp was resected and submitted in a unique specimen jar for histological evaluation. Categorical variables are reported using frequencies and proportions. Comparisons between groups were made using the Fisher’s exact test. Results: Twenty-six endoscopists from two tertiary academic centers performed 1,451 colonoscopies in which at least one diminutive polyp was found. There were a total of 3,012 diminutive polyps, 448 small polyps and 30 large polyps (see table). Approximately half of all diminutive polyps were detected in the left colon, whereas a larger proportion of polyps were in the left colon for small (59%) and large polyp (60%) categories. Fifty-three percent of all diminutive polyps were adenomas, none of which harbored high-grade dysplasia, villous features or carcinoma. A small proportion of diminutive polyps represented sessile serrated polyps (1.5%), none of which had dysplasia. Diminutive polyps were significantly less likely to harbor advanced histology (high-grade dysplasia, villous features or carcinoma) compared to small polyps (0.0% vs 4.0%, p<0.001) and large polyps (0.0% vs 30.0%, p<0.001). Conclusions: In a large multi-center prospective study evaluating real-time characterization of diminutive polyp histology, none of the over 3,000 diminutive polyps harbored any advanced histological features (villous histology, high-grade dysplasia and/or cancer). This finding reinforces existing literature that forgoing pathologic assessment for diminutive polyps characterized by NBI would be safe with negligible risk of missing advanced histology that requires more intensive treatment or surveillance, while polyps > 5 mm may not be ideal candidates for the resect and discard strategy based on their higher prevalence of advanced histological features. Supported by the ASGE Quality in Endoscopic Research Award.

Polyp features by size Total Number Polyps Location Right colon Left colon Missing Pathology Adenoma Tubular adenoma Tubulovillous adenoma High-grade dysplasia Sessile serrated polyp Without dysplasia With dysplasia Carcinoma Non-neoplastic* Other** Not retrieved/missing

 5mm 3,012 1,534 (50.9%) 1,431 (47.5%) 47 (1.6%) 1,600 (53.1%) 1,600 (53.1%) 0 0 45 (1.5%) 45 (1.5%) 0 0 1,288 (42.8%) 2 (0.1%) 77 (2.6%)

6-9 mm 448 184 (41.1%) 264 (58.9%) 0 319 (71.2%) 301 (67.2%) 16 (3.6%) 2 (0.4%) 17 (3.8%) 17 (3.8%) 0 0 109 (24.3%) 0 3 (0.7%)

 10 mm 30 12 (40.0%) 18 (60.0%) 0 25 (83.3%) 18 (60.0%) 5 (16.7%) 2 (6.7%) 4 (13.3%) 3 (10.0%) 1 (3.3%) 1 (3.3%) 0 0 0

402 Water Exchange Method Significantly Improves Adenoma Detection Rate: A Multi-Center, Randomized Controlled Trial Hui Jia*1, Yanglin Pan1, Felix W. Leung2, Xuegang Guo1, Kaichun Wu1 1 Xijing Hospital of Digestive Diseases, Fourth Military Medical University, Xi’an, Shaanxi, China; 2David Geffen School of Medicine, Los Angeles, CA Background & Aims: Concerns over low adenoma detection rate (ADR) and interval cancers brought new methods for increasing ADR. However, an ASGE technical report suggested none has sufficiently robust supportive data (GIE 2015;81:1122). Water exchange (WE) method reproducibly reduced insertion pain (GIE 2010;72:693). The impact of WE on ADR, the key quality indicator of colonoscopy, however, has not been fully defined, although retrospective analyses suggested an increase (GIE 2012;76:657). We test the hypothesis that WE significantly increases ADR. Methods: A prospective, randomized controlled trial (NCT02135601) was conducted at 6 centers in China. Patients undergoing colonoscopy were randomized to be examined by WE or traditional air insufflation (AI) method. The primary outcome was ADR. Intention-to-treat method was used for data analysis. Results: From April 2014 to July 2015, of 4352 consecutive patients considered, 1049 were excluded. 3303 were randomized to WE (nZ1653) or AI (nZ1650) group. Baseline characteristics were comparable (data not shown). Table 1 shows the outcomes related to adenoma detection. WE produced significantly higher overall ADR in all patients, in the subgroup of screening patients, and screening patients over the age of 50 years. WE also produced significantly higher detection rates for <10 mm adenomas and flat adenomas. Adenoma per colonoscopy was significantly higher in the WE group, but adenoma per positive colonoscopy were comparable. ADR in the screening male and female patients with AI were 25.8% and 15.7%, respectively. Multivariate analysis (Table 2) revealed age 50 years, male gender, Boston Bowel Prep score >6, BMI >25, WE method, screening or surveillance colonoscopy and withdrawal time >8 minutes were significant predictors of adenoma detection. Lower maximum insertion pain score, cleaner bowel preparation quality and less need for adjunct maneuvers (position change, abdominal compression or stiffness variation) were observed in the WE group (all p<0.05). No differences were found between the two groups regarding cecal intubation rate and withdrawal time. However, longer median cecal intubation time was seen in the WE group (7.4 min vs. 4.9 min, p<0.001). More patients were willing to repeat WE colonoscopy. Conclusion: The current prospective study confirms retrospective data that WE significantly improves ADR. Although the colonoscopists were not blinded, withdrawal time in cases without polyp and adenoma per positive colonoscopy were comparable between the WE and AI groups. These are consistent with equivalent withdrawal techniques being used in each group, and low likelihood of investigators biased by the “one-and-done” approach, respectively. The ADR in both male and female patients met quality guideline. Confirmation of higher willingness to repeat may be due to consistent reduction of maximum insertion pain. Table 1. ADR and procedure-related outcomes

Overall ADR, no. (%) Advanced ADR, no. (%) ADR per indications, no. (%) Screening Male Female 50y <50y Surveillance Diagnostic All adenoma, n (%) Size 5mm 6-9mm 10mm Shape Flat Sub-pedunculated Pedunculated Adenoma per colonoscopy Adenoma per positive colonoscopy Cecal intubation rate, no. (%) Insertion time (min), median (range) Withdraw time (min), mean (SD) With polyps Without polyps Boston bowel prep score, mean (SD) Maximum pain score, mean (SD) Patients willingness to repeat colonoscopy, no.(%)

WE (n[1653)

AI (n[1650)

p

303/1653 (18.3%) 70/1653 (4.2%)

221/1650 (13.4%) 50/1650 (3.0%)

<0.001 0.077

129/496 (26.0%) 78/250 (30.1%) 51/237 (21.5%) 108/367 (29.4%) 21/129 (16.3%) 53/182 (29.1%) 121/975(12.4%) 472 (28.6%)

111/541 (20.5%) 67/260 (25.8%) 44/281 (15.7%) 91/398 (22.9%) 20/143 (14.0%) 34/160 (21.3%) 76/949 (8.0%) 342 (20.7%)

0.039 0.283 0.089 0.040 0.615 0.106 0.001 0.003

361(21.8%) 73 (4.4%) 38 (2.3%)

271 (16.4%) 43 (2.6%) 28 (1.7%)

<0.001 0.020 0.238

407 (24.6%) 38 (2.3%) 27 (1.6%) 0.290.04 1.561.22 1632 (98.7%) 7.4 (5.9-10.2) 7.32.6 7.42.2 7.13.0 7.31.6 2.91.3 1464 (94.5%)

281 (17.0%) 35 (2.1%) 26 (1.6%) 0.210.03 1.551.24 1626 (98.5%) 4.9 (3.3-6.5) 7.42.2 7.52.9 7.23.0 7.0 2.3 3.61.2 1412 (91.5%)

0.001 0.762 0.897 <0.001 0.925 0.656 <0.001 0.600 0.749 0.673 <0.001 <0.001 0.001

*hyperplastic, lymphoid aggregate, inflammatory, normal tissue; **carcinoid.

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