Mucosal Endoscopic Dissection Research Articles

New Endoscopic Techniques

Major advancements in endoscopic techniques have allowed for the minimally invasive endoscopic management of many diseases that previously required surgical intervention. This review briefly describes major advances in endoscopic resection, including endoscopic mucosal resection and endoscopic submucosal dissection; endoscopic ablation, including radiofrequency ablation and cryotherapy; submucosal endoscopy, including peroral endoscopic myotomy and submucosal tunneling endoscopic resection; endoscopic access, including biliary access, pseudocyst drainage and direct endoscopic necrosectomy, and endoscopic gastrojejunostomy; endoscopic management of gastroesophageal reflux disease; and endoscopic management of obesity. Owing to the broad range of topics covered, extensive primary literature is provided for further reference for the interested reader. This review contains 8 figures and 55 references Key words: bariatric endoscopy, direct biliary access, endoscopic mucosal resection, endoscopic submucosal dissection, gastroesophageal reflux disease, gastrojejunostomy, peroral endoscopic myotomy, pseudocyst drainage, radiofrequency ablation, submucosal tumors

Sa1999 - use of Tranexamic Acid to Decrease Intra-Procedural Bleeding During Endoscopic Mucosal Resection and Submucosal Dissection

Sa1999 - use of Tranexamic Acid to Decrease Intra-Procedural Bleeding During Endoscopic Mucosal Resection and Submucosal Dissection

Surgery for upper gastrointestinal tract.

Incidence of gastric cancer is mainly in East Asia, and minimally invasive surgery such as endoscopic mucosal dissection, laparoscopic surgery and robotic surgery for gastric cancer has been developed mainly in this area. On the other hand, from the viewpoint of minimally invasive surgery for stomach diseases, various surgical techniques including benign diseases are performed in the world. In recent years, new techniques based on new concepts such as metabolic surgery for morbid obesity and combined operations of endoscope and laparoscope for submucosal tumor are being developed.

Endoscopic treatment for Barrett's oesophagus dysplasia and early cancer

Endoscopic treatment of early Barrett's oesophagus neoplasia is now proven to be a safe and effective alternative to oesophagectomy. An ideal candidate for endoscopic treatment should have dysplasia or carcinoma limited to the mucosa or superficial submucosa without lymphovascular invasion or poor differentiation. Two main types of endoscopic therapies are used: (1) endoscopic resection, which comprises of endoscopic mucosal resection or endoscopic submucosal dissection for removal of visible lesions en bloc and (2) endoscopic ablation utilising argon plasma coagulation, radiofrequency ablation or, more recently, cryotherapy. Although endoscopic resection is the cornerstone for Barrett's endotherapy, ablative techniques are complementary in achieving complete eradication of the columnar epithelium and dysplasia.

Mixed control scheme for accurate control of robotic flexible endoscope

Tendon-driven endoscopes are mainly used in the current practice. Their flexible bodies may change frequently during the processes of biopsy, endoscopic mucosal resection or endoscopic submucosal dissection. These changes lead to backlash hysteresis and nonlinear friction effects, which make it difficult to achieve accurate control. To address this problem, a mixed control scheme based on the combination of discrete and continuous models was proposed and quantitatively compared with a conventional feedback control scheme, a feedforward control scheme and an adaptive control scheme. These experiments were conducted using a robotic gastroscope. The results showed that our control scheme can achieve more accurate tracking performance when the configuration changes frequently, with mean square error of tracking performance decreased by 50–75%.

Transplantation of tissue-engineered cell sheets for stricture prevention after endoscopic submucosal dissection of the oesophagus.

Endoscopic mucosal dissection (ESD) is a treatment option for oesophagus tumours localized to the mucosa enabling en bloc removal of large lesions. The resulting larger mucosal defects have resulted in an increase in the occurrence of post-treatment strictures. Transplantation of autologous cell sheets, cultured from oral mucosa, has been shown to prevent post-ESD strictures. The aim of the study was to assess the efficacy and safety of cell sheet transplantation after oesophageal ESD in a Western patient population where reflux-associated pre-malignant and malignant conditions predominate. Patients with Barrett's oesophagus associated high-grade dysplasia or early adenocarcinoma where ESD entailed a resection >3 cm in length and ≥75% of the circumference were eligible for treatment under hospital exemption. Cell sheets were cultured from buccal mucosa according to Good Manufacturing Practice and were endoscopically applied to the post-ESD defect directly after resection. Patients were followed with weekly endoscopy examinations, including confocal laser microscopy, for a total of four weeks. Five patients were treated. ESD was extensive with resections being circumferential in three patients and 9-10 cm in length in two. The number of transplanted cell sheets ranged from two to six. Three patients developed strictures requiring two to five dilatation sessions. Cell sheet transplantation shows to be safe and feasible in a Western population. Results suggest that transplantation has a protective effect on the mucosal defect after ESD, decreasing both the risk for and extent of stricture formation.

Additional surgical resection after endoscopic mucosal dissection for early gastric cancer: A medium-sized hospital's experience

PurposeIn Japan, the majority of early gastric cancers (EGCs) are now treated with endoscopic submucosal dissection (ESD). Patients with non-curative lesions treated by ESD are advised to undergo additional surgical resection (ASR) based on guidelines from the Japan Gastroenterological Endoscopy Society (JGES) and Japanese Gastric Cancer Association (JGCA). However, many studies have demonstrated that residual cancer and lymph node metastasis are only rarely found in ASR specimens. Here we retrospectively analyzed the conditions that could enable the avoidance of unnecessary ASR. MethodsThe ESD data for 114 absolute indication lesions and 26 lesions of expanded indication lesions were analyzed. The indications and the curability were evaluated according to the JGES/JGCA guidelines. ResultsThe rates of non-curative resection and ASR were significantly higher in the expanded indication group compared to the absolute indication group (26.9% and 19.2% vs. 7.9% and 0.9%, respectively). ASR was performed for six patients. Three of their ARS specimens contained neither residual cancer nor lymph node metastasis, and the pathological findings of the preceding ESD specimens deviated slightly from the curative criteria defined by the guidelines. The conditions of the lesions that did not meet the curative criteria were as follows: (1) sm1 invasion of undifferentiated-type lesion <10 mm dia., (2) 21–25 mm dia. mucosal undifferentiated-type lesion, or (3) peacemeal resection with a horizontal margin positive for the mucosal differentiated-type. ConclusionsThese data suggest that a close follow-up without ASR might be appropriate for patients in the above-mentioned three categories after non-curative ESD for EGC.

Predictive Factors for Pain After Endoscopic Resection of Gastric Tumors

Abdominal pain is a common complaint following endoscopic resection (ER). To investigate the predictive factors for abdominal pain after ER. Patients who were scheduled to undergo endoscopic mucosal resection or endoscopic submucosal dissection for the treatment of gastric adenoma or cancer were prospectively enrolled. Pain scores were checked every 6h after ER and whenever patients complained of pain by using a 0-10 pain scale. If the pain score exceeded 5, 25mg of intravenous (IV) pethidine was administered. Among 156 patients who underwent ER, 66 (42.3%) received IV pethidine due to moderate/severe abdominal pain. Both the number of patients complaining of abdominal pain and the pain scores decreased with time following the procedure, with only a few patients complaining of mild abdominal pain 2days after ER. Multivariate analysis showed that female sex [odds ratio (OR) 2.88; confidence interval (CI) 1.31-6.33], tumor location in the lower third of the stomach (OR 5.46; CI 2.31-12.92), and procedures time more than 60min (OR 2.96; CI 1.26-6.98) were significant predictive factors for developing pain after ER. Female sex, tumor location in the lower third of the stomach, and longer procedure time were significantly associated with pain after ER. Close monitoring and active management of pain is recommended for patients who have these risk factors. With these efforts, the majority of patients could experience pain relief within 2days after the procedure.

Submucosal Lipoma of the Rectum Presenting as Rectal Prolapse and Appearing as Adenomatous Polyp on Confocal Laser Endomicroscopy: a Case Report and Literature Review

Lipomas of the gastrointestinal (GI) tract are rare neoplasm, with rectum being the most uncommon site of occurrence. Most of these lesions are asymptomatic, however, the larger sized ones may have varied presentations ranging from vague abdominal discomfort to over symptoms simulating malignancy. Pro lapse of the rectum is a very rare presentation of rectal lipomas that warrants further investigations to avoid misdiagnosis. Colonoscopy and endoscopic ultrasound (EUS) are important modalities for preoperative diagnosis, nevertheless, preoperative diagnosis remains difficult in some cases. Confocal laser endomicroscopy (CLE) is a novel endoscopic imaging modality that allows tissue diagnosis at cellular and sub cellular levels, and bears particular significance to the diagnosis of polypoidal lesions. However, application of CLE for sub mucosal lesions such as lipomas of the colorectum has not being documented yet to the best of our knowledge. Here we report a case of lipoma of the rectum presenting with features of rectal pro lapse. Colonoscopy and CLE were performed, the findings of both of which were suggestive of an adenomatous polyp, thereby providing no diagnostic advantage of CLE over white light endoscopy for this particular case of rectal lipoma. However, EUS revealed a sub mucosal lesion. Subsequently, sub mucosal endoscopic dissection (SMD) of the mass was performed, that was later confirmed to be a sub mucosal lipoma histopathologically. This reiterates the importance of histopathology for the diagnosis of GI lesions over novel “virtual microscopy” techniques.

PWE-124 Complex Colorectal Polyps: A Tertiary Centre Experience; Tailoring The EMR Technique to The’Polyp

Introduction Features that characterise polyp complexity should be clearly defined and recognised to avert suboptimal piecemeal endoscopic mucosal resection (p-EMR) strategies and need for salvage surgery. Methods A prospective database of all colorectal polyps excised at our tertiary referral centre between Jan 2010 and August 2012 was collected. Standard p-EMR, p-EMR using a 20 mm spiral snare (sp-EMR), and hybrid p-EMR (hp-EMR; p-EMR plus endoscopic mucosal ablation or endoscopic submucosal dissection) were performed. Multinomial regression analysis was utilised to define characteristic features of complex polyps and factors associated with the chosen resection technique. Results Of 330 patients with 341 polyps (mean size 3.7 cm), 81% (261/323, p i) tertiary referrals (sp-EMR, OR 3.41, p ), ii) incomplete polyp lift (hp-EMR, OR 8.3 > sp-EMR, OR 1.19 p iii) previous polypectomy attempt (hp-EMR, OR 2.77, p = 0.02), iv) larger polyp size (for an increase of 1 cm – hp-EMR (OR 1.37)/sp-EMR (OR 1.66,) p v) polyps in the rectosigmoid location (sp-EMR and hp-EMR, p vi) Paris IIa+IIb polyps (sp-EMR, OR 5.01 and hp-EMR, OR 2.9, p –0.007). Conclusion Complex colorectal polyps referred to this tertiary centre were characterised by polyp size ≥ 4 cm, caecal location, previous unsuccessful polypectomy, difficult endoscopic access, or incomplete polyp lift. Advanced techniques such as hybrid-pEMR and spiral p-EMR were required in 33% of tertiary referrals. Disclosure of Interest None Declared

P-211 Revisit of endoscopic ultrasonography to evaluate depth of invasion of early gastric cancer before endoscopic mucosal dissection compared with conventional endoscopy

P-211 Revisit of endoscopic ultrasonography to evaluate depth of invasion of early gastric cancer before endoscopic mucosal dissection compared with conventional endoscopy

Endoscopic therapy for gastroduodenal neuroendocrine neoplasms

Neuroendocrine neoplasms (NEN) represent a group of potentially malignant tumors, which can be located in every section of the gastrointestinal tract, the pancreas and the bronchopulmonary system. Gastroduodenal NENs have a relatively good prognosis in comparison to other subentities, e.g. pancreatic or ileojejunal NENs. In the stomach there are four different types of NENs, while in the duodenum there are five types and all vary in the malignant potential and the therapeutic approach. Due to the simple access endoscopic methods not only have diagnostic but also important therapeutic relevance in this subgroup. Lesions smaller than 1cm can easily be resected with forceps or snare resection and for larger lesions up to 2cm more invasive strategies, such as endoscopic mucosal resection (EMR) or endoscopic submucosal dissection (ESD) are available. Important criteria in gastric NEN for the risk evaluation of endoscopic treatment alone are the size of the lesion, depth of invasion and the tumor biology, e.g. neuroendocrine tumor (NET) G1/G2 versus neuroendocrine carcinoma (NEC) G3. In duodenal NEN the aforementioned risk factors also apply and in addition only lesions outside the ampulla of Vater should be endoscopically resected whereas periampullary lesions need to be addressed surgically. As an individualized therapeutic approach the possibility of a combined endoscopic and laparoscopic resection technique exists. Follow-up endoscopic investigations are necessary, especially in gastric type 1 NENs, which have a tendency to relapse.

Detection and Management of Early Gastric Cancer.

Early gastric cancer (EGC), defined as being confined to the submucosa, is a curable condition. In recent years, endoscopic mucosal resection (EMR) and endoscopic submucosal dissection (ESD) have been widely applied to subgroups of mucosal cancers, thereby avoiding the burden of operation while preserving gastric function. However, it can be difficult to identify mucosal cancers, which often evade detection due to their flat shapes without ulceration. Proper preparation to clean the mucosal surface, detailed systematic observation of the entire stomach, and the use of high-resolution systems for both endoscopies equipped with image-enhanced modality and monitors would facilitate the detection of such lesions. It is also critical to evaluate the resected specimen to confirm completeness of resection (tumor-free lateral and vertical margins as well as the absence of lymphatic and vascular invasion). If the resection is incomplete, further treatment is usually recommended-further endoscopic resection for patients with positive lateral margins or surgery for patients with positive vertical margins or with lymphatic or vascular involvement. The five-year survival for endoscopically resected EGC is excellent-and comparable to that of surgical therapy. Since most gastric cancers are caused by Helicobacter pylori, this infection should be tested for routinely. If a patient is H. pylori-positive, eradication is recommended, as heterotopic, metachronous recurrence of EGC is subsequently reduced. Importantly, basic principles for early diagnosis and endoscopic treatment of EGC can be applied to neoplasms arising in other parts of the gut, such as the esophagus and colon, and would be beneficial for patients through preserving organ function and minimizing operative intervention.

274 Endoscopic Mucosal Resection May Not Be Appropriate for All T1a Gastric Cancers

Endoscopic mucosal resection (EMR) and endoscopic mucosal dissection (EMD) are widely accepted in Asia for treatment of early gastric cancer (EGC). Few studies have examined lymph node (LN) metastasis rates in Western populations. Because EMR and EMD are becoming more widely practiced in the US, we sought to determine LN metastasis rates and clinical outcomes of EGC in a racially heterogeneous Western population.

Su1491 Predictive Factors of Pyloric Stenosis After Endoscopic Mucosal Dissection and Its Proper Management

the large resection surface. Furthermore, a combined clip and PGA felt method may prevent postoperative complications.

Tu1732 Procedure Time Analysis of Endoscopic Submucosal Dissection and Multiple Factors That Have an Affect on Procedure Time

Endoscopic mucosal dissection (ESD) has become a widely accepted therapeutic method for gastric adenoma and early gastric cancer. However, it takes a long time to perform ESD procedure because of technical difficulties. So there has been a lot of effort to analyze factors that have an affect on procedure time. Especially, in this study, we analyzed not only total procedure time but also subdivision of the time -inspection, incision, dissection, coagulation time.

Application of carbon dioxide to the upper gastrointestinal endoscopic submucosal dissection

Objective To explore the value of carbox dioxide(CO2) for the upper gastrointestinal endoscopic mucosal dissection(ESD). Methods A total of 158 patients who underwent ESD from January 2012 to May 2014 at Endoscopy Center of Dongguan Hospital were enrolled in the study. The patients were randomly divided into air group and CO2 group. The arterial partial pressure of CO2(PaCO2), the monitering results of SpO2 before, during, afte operation, abdominal pain after operation and postoperative complications were assessed. The safety and advantage of CO2 of the upper gastrointestinal ESD were comparative analyzed. Results PaCO2 of air group and CO2 group during the ESD procedures[(47.8±5.4)mmHg, (45.1±5.5)mmHg] was significantly higher than that before[(37.2±4.6)mmHg, (36.3±3.9)mmHg] (P 0.05); all the SpO2 were greater than 90%, and it was not significantly different between the two groups(P>0.05). The abdominal pain score of CO2 group was significantly lower than that of air group less than 2 h after wake-up (P 0.05). The bleeding rate of air group and CO2 group during and after operation was not significantly different(P>0.05), and there were no other serious complications. Conclusion CO2 is safe in the upper gastrointestinal ESD, and it can reduce postoperative abdominal pain, so it is suitable for clinical application. Key words: Carbon dioxide; Air; Endoscopic mucosal dissection

Focal Intramucosal Adenocarcinoma Occurring in Gastric Hyperplastic Polyps: Two Case Reports.

Gastric hyperplastic polyps are generally considered benign lesions, although rare cases of adenocarcinoma have been reported. Two cases of intramucosal adenocarcinoma originating from gastric hyperplastic polyps that were successfully removed by endoscopic mucosal resection or endoscopic submucosal dissection are reported. On pathological examination, adenocarcinoma limited to the hyperplastic foveolar epithelial mucosa of the gastric hyperplastic polyps was observed.

Changes in Upper Gastrointestinal Diseases according to Improvement of Helicobacter pylori Prevalence Rate in Korea

Helicobacter pylori can cause variety of upper gastrointestinal disorders such as peptic ulcer, mucosa associated lymphoid tissue (MALT)-lymphoma, and gastric cancer. The prevalence of H. pylori infection has significantly decreased in Korea since 1998 owing to active eradication of H. pylori. Along with its decrease, the prevalence of peptic ulcer has also decreased. However, the mean age of gastric ulcer increased and this is considered to be due to increase in NSAID prescription. Gastric cancer is one of the leading causes of cancer deaths in Korea and Japan, and IARC/WHO has classified H. pylori as class one carcinogen of gastric cancer. Despite the decreasing prevalence of H. pylori infection, the total number of gastric cancer in Korea has continuously increased from 2006 to 2011. Nevertheless, the 5 year survival rate of gastric cancer patients significantly increased from 42.8% in 1993 to 67% in 2010. This increase in survival rate seems to be mainly due to early detection of gastric cancer and endoscopic mucosal dissection treatment. Based on these findings, the prevalence of peptic ulcer is expected to decrease even more with H. pylori eradication therapy and NSAID will become the main cause of peptic ulcer. Although the prevalence of gastric cancer has not changed along with decreased the prevalence of H. pylori, gastric cancer is expected to decrease in the long run with the help of eradication therapy and endoscopic treatment of precancerous lesions.

Sa1595 Germanium Photodiode: New Technique for the Development of Endoscopic Implantable Gastric Pacemaker

Sa1593 Comparing the Feasibility and Efficacy of Combined Endoscopic and Transumbilical Single-Port Laparoscopic Surgery With Standard Laparoscopic Resection of Gastric Stromal Tumors Wen LI*, Zikai Wang, Baoqing Jia, Xiaohui Du, Xiaopeng Wang, Tingting Huang, Xuan Su, Lili Wu, Xiuxue Feng Gastroenterology and Hepatology, the Chinese PLA General Hospital, Beijing, China; Department of Oncological Surgery, the Chinese PLA General Hospital, Beijing, China; Department of General Surgery, the Chinese PLA General Hospital, Beijing, China Background: Complete endoscopic or laparoscopic resection of gastric stromal tumors (GST) in the cardia & fundus is only partially feasible. A combined endoscopic-laparoscopic approach has been recently recognized as the favorable modality for these lesions. Aims: To assess the feasibility and efficacy of combined endoscopic and transumbilical single-port laparoscopic surgery (CETSLS) for the GST. Methods Between April, 2010 and July, 2013, 14 patients with GST were assigned to undergo CETSLS (n Z 7) and standard laparoscopic surgery (SLS) (n Z 7) at the Chinese PLA general hospital. The subjects undergiong CETSLS were managed with laparoscopy-assisted endoscopic techniques (i.e. endoscopic snare resection, endoscopic mucosal resection and endoscopic submucosal dissection) or endoscopy-assisted laparoscopic techniques (i.e. laparoscopic gastric wedge resection). Several parameters were analyzed: operation time, conversion rate, operative complications, pain scores, cost and duration of hospital stay, cosmetic satisfaction and follow-up evaluation. Results: There was no difference in the age, gender and indications for CETSLS and SLS groups. All lesions were located in the gastric cardia/ fundus, They were confirmed to be GST on immunohistochemical staining and showed similar mean diameter. CETSLS was successfully carried out in 85.7% (6/7) of our patients with one case requiring conversion to open surgery due to intraoperative bleeding. However, there was no conversion in the SLS group. The mean operative time was similar in both groups (108.0 59.2 vs. 164.3 49.3 minutes: P Z 0.09). The intra-operative blood loss was lower in CETSLS than SLS group (25.0 15.2 ml vs. 74.3 32.6 ml: P Z 0.006). Complete resection rate was 100%. It was achieved without serious complications in both groups. Despite a shorter postoperative hospitalization time in the CETSLS group (5.7 1.4 vs. 8.9 2.8 days, PZ 0.03), the cost of hospitalization was almost similar (40942.8 11158.6 vs. 57246.7 16049.4 RMB, P Z 0.06). There was no re-admission or tumor recurrence during a median follow-up of 26 months (range, 4 43 months). Conclusions: CETSLS is a feasible and effective technique, which offers superior cosmesis during resection of the GST.