Yunho Jung

Efficacy of full-thickness GI perforation closure with a novel over-the-scope clip application device: an animal study

BACKGROUND A novel, over-the-scope clip (OTSC) system may be suitable for closure of various GI perforations. The strength and maximum diameter of closure for a single OTSC, however, are unknown. OBJECTIVE To determine the maximum closure capacity (diameter) and pressure threshold for a single OTSC. DESIGN Prospective ex-vivo study. SETTING Academic medical center. METHOD Full-thickness, standardized defects of 5 mm, 10 mm, 15 mm, 20 mm, and 25 mm were created in porcine stomachs. Similarly, full-thickness defects of 10 mm, 20 mm, 25 mm, 30 mm, and 35 mm were created in porcine colons. A single OTSC was endoscopically deployed 5 times for each full-thickness defect size in an ex-vivo endoscopic simulator. MAIN OUTCOME MEASUREMENTS Each closure site was tested under water with compressed air for burst pressure. RESULTS We achieved successful closure in all stomach defects ranging from 5 to 20 mm by using 12-mm OTSCs with short teeth and colon defects ranging from 10 to 30 mm with 14-mm OTSCs with short teeth. Mean (± standard deviation [SD]) burst pressures for the gastric closure sites were 74.9 ± 17.5 mm Hg for 15-mm defects, 49.3 ± 21.6 mm Hg for 20-mm defects, and 15.2 ± 4.1 mm Hg for 25-mm defects. Mean (± SD) burst pressures for the colon closure sites were 117.9 ± 40.1 mm Hg for 20-mm defects, 57.4 ± 4.2 mm Hg for 30-mm defects, and 10.9 ± 7.6 mm Hg for 35-mm defects. LIMITATIONS Ex-vivo study, does not reflect difficult locations. CONCLUSION Full-thickness tissue defects ranging from 5 to 20 mm in the stomach and from 10 to 30 mm in the colon can be closed adequately with a single OTSC in an ex-vivo experimental setting. Tissue defects larger than 20 mm in the stomach and 30 mm in the colon may require more than one OTSC or supplemental endoclips to achieve adequate closure. Endoscopic inspection of the closure site does not assure adequate closure of larger perforations.

Prospective, randomized comparison of 3 different hemoclips for the treatment of acute upper GI hemorrhage in an established experimental setting

BACKGROUND Recently, endoscopic clip application devices have undergone redesign and improvements to optimize their clinical use and effectiveness. Initially designed for the treatment of bleeding nonvariceal lesions, these devices are also increasingly used for the closure of perforations, fistulas, and anastomotic leaks. Several clinical studies, both randomized and nonrandomized, have used endoscopic hemoclips for hemostasis. However, no comparative studies have yet been reported in the literature comparing the latest endoscopic clip devices for usability and effectiveness for hemostasis of acute upper GI hemorrhage. OBJECTIVE We aimed to compare the usability and efficacy of 3 different types of endoscopic clip application devices in an established experimental setting by using a porcine ex-vivo simulator of upper GI hemorrhage. DESIGN Randomized, controlled, ex-vivo study. SETTING Academic medical center. METHODS Spurting vessels were created within ex-vivo porcine stomachs as published in prior studies. The vessels were attached to a pressure transducer to record the pressure of the circulating blood replacement. Before the initiation of bleeding, each vessel was randomized to 1 of 3 endoscopic clipping devices: 2 different commonly used hemoclips deployed through the working channel and 1 novel clip deployed via an over-the-scope applications device. Two investigators treated 45 bleeding sites (15 bleeding sites for each device at various randomized locations in the stomach: fundus, body, and antrum). MAIN OUTCOME MEASUREMENTS Usability was measured via the endpoints of procedure time and quantity of clips required to achieve hemostasis. Efficacy was measured via the endpoint of pressure increase (Δp) from baseline to after treatment. RESULTS All of the 45 hemostasis treatments were carried out successfully. The mean procedure times were significantly different among the hemoclips, with the clip deployed in an over-the-scope fashion requiring significantly less time to attain hemostasis compared with the other 2 clips. For number of clips needed to attain hemostasis, the clip deployed in an over-the-scope fashion was significantly superior to the others. There were also significant differences among the changes in pressure (Δp ± SD) among the different hemoclips tested. LIMITATIONS Ex-vivo study. CONCLUSIONS In this prospective, randomized ex-vivo study, we observed significant differences in the usability (time to achieve hemostasis and number of clips required) and the efficacy (change in pressure achieved by the hemoclips) among the 3 clips. The clip applied in the over-the-scope fashion was superior to the other 2 tested clips with regard to time to achieve hemostasis and number of clips required.

Prospective, randomized comparison of a prototype endoscope with deflecting working channels versus a conventional double-channel endoscope for rectal endoscopic submucosal dissection in an established experimental simulation model (with video)

BACKGROUND A prototype endoscope was designed to improve visualization and dissection of tissue with the use of 2 working channels with different deflections. OBJECTIVE To evaluate the efficacy and operability of a prototype endoscope in comparison with a conventional double-channel endoscope for rectal endoscopic submucosal dissection (ESD). DESIGN Randomized, prospective, controlled, ex vivo study. SETTING Academic medical center. METHODS A total of 80 standardized artificial lesions measuring 3 × 3 cm were created approximately 5 cm from the anal verge in fresh ex vivo porcine colorectal specimens. Two endoscopists each completed 20 cases with the prototype endoscope and 20 cases with the conventional endoscope. MAIN OUTCOME MEASUREMENTS An independent observer recorded procedure time, specimen size, en bloc resection, and perforation rate. RESULTS For the ESD novice, the mean submucosal dissection time (10.5 ± 3.8 vs 14.9 ± 7.3 minutes; P = .024) and total procedure time (18.1 ± 5.2 vs 23.6 ± 8.2 minutes; P = .015) were significantly shorter in the prototype group in comparison with the conventional group. For the ESD expert, there was no significant difference between the mean circumferential resection, submucosal dissection, and total procedure time (prototype group 14.2 ± 6.0 minutes, conventional group 14.2 ± 8.8 minutes; P = .992). The overall perforation and en bloc resection rates were not significantly different between groups. LIMITATIONS Ex vivo study. CONCLUSION In this ex vivo prospective comparison study, there was a technical advantage for the ESD novice with the prototype endoscope that resulted in a shorter procedure time, which was not observed for cases performed by the ESD expert.

Successful Endoscopic Resection of Large Pedunculated Brunner's Gland Hamartoma Causing Gastrointestinal Bleeding Arising from the Pylorus

Brunners gland hamartoma is a rare benign small bowel neoplasm and most lesions are small and asymptomatic. However, large hamartoma-related obstructive symptoms and hemorrhage related to tumor ulceration manifest as hematemesis or melena. The exact pathogenesis if these lesions is not well known, but they are thought to be frequently associated with Helicobacter pylori infections and chronic pancreatitis. We report the case of a 45-year-old man who presented with melena due to a large pedunculated Brunners gland hamartoma arising from the pylorus. It was successfully removed by endoscopic mucosal resection with piecemeal technique because of too large tumor size for application of a conventional snare.

Usefulness of the Forrest Classification to Predict Artificial Ulcer Rebleeding during Second-Look Endoscopy after Endoscopic Submucosal Dissection

Background/Aims: Delayed post-endoscopic submucosal dissection (ESD) bleeding (DPEB) is difficult to predict and there is controversy regarding the usefulness of prophylactic hemostasis during second-look endoscopy. This study evaluated the risk factors related to DPEB, the relationship between clinical outcomes and the Forrest classification, and the results of prophylactic hemostasis during second-look endoscopy. Methods: Second-look endoscopy was performed on the day after ESD to check for recent hemorrhage or potential bleeding and the presence of artificial ulcers in all patients. Results: DPEB occurred in 42 of 581 patients (7.2%). Multivariate analysis determined that a specimen size ≥40 mm (odds ratio [OR], 3.03; p=0.003), and a high-risk Forrest classification (Forrest Ib+IIa+IIb; OR, 6.88; p<0.001) were risk factors for DPEB. DPEB was significantly more likely in patients classified with Forrest Ib (OR, 24.35; p<0.001), IIa (OR, 12.91; p<0.001), or IIb (OR, 8.31; p<0.001) ulcers compared with Forrest III ulcers. There was no statistically significant difference between the prophylactic hemostasis and non-hemostasis groups (Forrest Ib, p=0.938; IIa, p=0.438; IIb, p=0.397; IIc, p=0.773) during second-look endoscopy. Conclusions: The Forrest classification of artificial gastric ulcers during second-look endoscopy seems to be a useful tool for predicting delayed bleeding. However, routine prophylactic hemostasis during second-look endoscopy seemed to not be useful for preventing DPEB.

Electrohydraulic lithotripsy of an impacted enterolith causing acute afferent loop syndrome.

Afferent loop syndrome caused by an impacted enterolith is very rare, and endoscopic removal of the enterolith may be difficult if a stricture is present or the normal anatomy has been altered. Electrohydraulic lithotripsy is commonly used for endoscopic fragmentation of biliary and pancreatic duct stones. A 64-year-old man who had undergone subtotal gastrectomy and gastrojejunostomy presented with acute, severe abdominal pain for a duration of 2 hours. Initially, he was diagnosed with acute pancreatitis because of an elevated amylase level and pain, but was finally diagnosed with acute afferent loop syndrome when an impacted enterolith was identified by computed tomography. We successfully removed the enterolith using direct electrohydraulic lithotripsy conducted using a transparent cap-fitted endoscope without complications. We found that this procedure was therapeutically beneficial.

Mo1519 The Efficacy of the Novel Tissue Grasper-Clips Technique for Large Sigmoid Colon Perforations in Experimental Simulation Model

Mo1518 One-Step Fluoroless EUS-Guided CBD and Gallbladder Drainage Change of Paradigm? Markus Dollhopf*, Ilaria Tarantino, Andres Sanchez-Yague, Fabia Attili, Alberto Larghi Dept. Gastroenterology and Hepatology, Klinikum Neuperlach, Munich, Germany; Endoscopy Unit, Department of Diagnostic and Therapeutic Services, Mediterranean Institute for Transplantation and Advanced Specialized Therapies (ISMETT), Palermo, Italy; Gastroenterology Dept, Hospital del Sol, Marbella, Spain; Digestive Endoscopy Unit, Catholic University, Rome, Italy Background and Aims: EUS-guided drainage of unresectable malignant common bile duct strictures (CBD) after failed ERCP and of the gallbladder (GB) in patients with acute cholecystitis unfit for surgery are alternative minimally invasive treatment modalities to percutaneous drainage. Up to now, available EUS-techniques to perform these procedures have required frequent accessories exchange with risk of dislocation and therefore of bile leak and perforation. Our aim was to investigate one-step fluoroless EUS-guided CBD and GB drainage by using a novel lumen-apposing, self-expanding fully covered metal stent incorporated in an electrocautery enhanced delivery system that allows direct puncture of a target, insertion and release in a one-step-fashion. Methods: Retrospective analysis of all consecutive patients with unresectable malignant CBD strictures after failed ERCP or cholecystitis unfit for surgery who were treated by EUS-guided placement of Hot-Axios (Xlumena Inc., Mountain View, California, USA). All procedures were performed without fluoroscopy using EUS and endoscopic guidance. Technical success was defined by adequate placement of Hot-Axios-Stent with established drainage. Clinical success was defined by R80% decrease of obstructive parameters or resolution of cholecystitis. Results: 19 patients (Mean age 75yrs; M/F: 10/ 9) with malignant obstructive jaundice (13) and cholecystitis (6) were included. CBD access was used in 9 pts. (8 transduodenal, 1 transgastric) and GB access in 10 pts. For CBD drainage a 6x8mm (3), 8x8mm (3) and 10x10mm (3) were used while

Tu1512 The Clinical Feature of the Exposed Vessels in Ulcer Base Over Time After Prophylactic Argon Plasma Coagulation in Colonic Endoscopic Mucosal Resection

documented RP and bleeding were reviewed. Nine males had prostate cancer and one female had vaginal cancer. Mean age was 72 years. Two patients were on warfarin, one on aspirin, and the last on aspirin and clopidogrel. Five patients had CKD, and 2 of the 10 patients were transfusion dependent. Prior treatments were attempted in 6 patients–2 recieved APC of whom 1 patient failed 5 sessions. Canasa, formalin, and epinephrine injection were previously used. Halo 90 focal catheter was used in 6 patients; Halo 60 was used in the remaining four. Nine out of ten patients had excellent response: all had resolution of bleeding and the majority had improved hemoglobin. Seven patients required only one session. Two patients required two sessions, and one patient five sessions. Of interest, of those requiring 2 RFA sessions, one was on warfarin and the other had received 5 prior APC sessions. The patient who received 5 RFA sessions was considered refractory to treatment. His comorbidities included coagulopathy, CKD, and altered rectal anatomy. Symptoms resolved after an additional treatment with the Halo Channel RFA catheter, which seemed to provide improved contact, enabling adequate hemostasis. No adverse effects were observed in any patient. Conclusion: To our knowledge this is the largest case series of patients with RP treated with RFA. This study demonstrates both efficacy and safety of this treatment modality. Our study showed O 90% success rate. Advances in through-the-scope technology may further improve success. RFA may provide advantages over other treatment methods including broader surface area coverage, consistent depth of ablation, improved re-epithelialization, and lower risk of complication. RFA may be considered first line therapy for RP or to those who failed other treatments.

Tu1541 The Usefulness of a Newly Developed It Knife for Rectal Endoscopic Submucosal Dissection in an Established Experimental Simulation Model

Figure 1. Survival Curves of all 283 Patients who Underwent Colorectal ESD Tu1541 The Usefulness of a Newly Developed It Knife for Rectal Endoscopic Submucosal Dissection in an Established Experimental Simulation Model Yunho Jung*, IL-Kwun Chung, Young Sin Cho, Tae Hoon Lee, Sang-Heum Park, Sun-Joo Kim Gastroenterology, Soon Chun Hyang Cheonan Hospital, Cheonan, Republic of Korea Background/Aims: Colorectal endoscopic submucosal dissection (ESD) is still challenging because it has some dsadvantages such as technical difficulty, a long procedure time and higher complication rate such as bleeding (about 10%) and perforation (4w10%). The newly developed IT knife (IT-knife nano, Olympus Optical Co., Tokyo, Japan) was designed for colorectal ESD. It has a smaller insulation tip and small disk blade perpendicular to the main blade for improving the movability in small lumen and safety with reducing burning effect on muscle layer. The aim of this study was to evaluate the efficacy of newly developed IT knife for the rectal ESD in comparison with conventional ESD. Methods: This study was designed as a prospective, controlled, and ex-vivo study. A total of 40 standardized artificial lesions measuring 3 x 3 cm was created approximately 10 cm from anal verge in fresh ex vivo porcine colorectal specimens using the EASIE-R simulator platform (Endosim LLC, Berlin, MA). An experienced endoscopist completed each 20 cases of ESD with conventional ESD knifes such as dual and hook knife (Conventional knife group) and 20 cases with newly developed IT knife (New knife group). Independent observer recorded circumferential resection time, submucosal dissection time, total procedure time, injection amount, En bloc and perforation rate. Results: The mean size of resected specimen was 4.1 0.6 cm (Long axis) x 3.7 0.4 cm (Short axis). The mean submucosal dissection time (6.4 2.9 vs 10.5 3.8 minutes; PZ0.01) and total procedure time (13.2 4.5 vs 18.0 6.2 minutes; PZ0.008) were significantly shorter in the new knife group in comparison with the conventional knife group. The mean injection frequency of new knife group was significantly smaller than conventional knife group (2.1 0.3 vs 2.6 0.6, PZ0.006). There was only one perforation (1/20) in conventional knife group. The en bloc rate was 95% (19/20) in both groups. Conclusion: Newly developed IT knife seems to be safe and reduce the time for rectal ESD in ex-vivo setting. Further animal or clinical trial needed for proving the new knife’s clinical benefit. Results of conventional knife group and new knife group AB578 GASTROINTEST Conventional Knife group (20) INAL ENDOSCOPY Vo New knife group (20) lume 79, No. 5 P value Circumferential cutting (minutes) 3.9 1.5 3.4 1.4 0.275 Submucosal dissection (minutes) 10.5 3.8 6.4 2.9 0.001 Total procedure time (minutes) 18.0 6.2 13.2 4.5 0.008 Injection amount (cc) 27.3 11.1 24.8 7.9 0.416 Injection frequency 2.6 0.6 2.1 0.3 0.006 S : 2014 Conventional Knife group (20) New knife