General Endoscopists Research Articles

Artificial Intelligence for Real-Time Prediction of the Histology of Colorectal Polyps by General Endoscopists.

Real-time prediction of histologic features of small colorectal polyps may prevent resection and/or pathologic evaluation and therefore decrease colonoscopy costs. Previous studies showed that computer-aided diagnosis (CADx) was highly accurate, though it did not outperform expert endoscopists. To assess the diagnostic performance of histologic predictions by general endoscopists before and after assistance from CADx in a real-life setting. Prospective, multicenter, single-group study. (ClinicalTrials.gov: NCT04437615). 6 centers across the United States. 1252 consecutive patients undergoing colonoscopy and 49 general endoscopists with variable experience in real-time prediction of polyp histologic features. Real-time use of CADx during routine colonoscopy. The primary end points were the sensitivity and specificity of CADx-unassisted and CADx-assisted histologic predictions for adenomas measuring 5 mm or less. For clinical purposes, additional estimates according to location and confidence level were provided. The CADx device made a diagnosis for 2695 polyps measuring 5 mm or less (96%) in 1252 patients. There was no difference in sensitivity between the unassisted and assisted groups (90.7% vs. 90.8%; P = 0.52). Specificity was higher in the CADx-assisted group (59.5% vs. 64.7%; P < 0.001). Among all 2695 polyps measuring 5 mm or less, 88.2% and 86.1% (P < 0.001) in the CADx-assisted and unassisted groups, respectively, could be resected and discarded without pathologic evaluation. Among 743 rectosigmoid polyps measuring 5 mm or less, 49.5% and 47.9% (P < 0.001) in the CADx-assisted and unassisted groups, respectively, could be left in situ without resection. Decision making based on CADx might differ outside a clinical trial. CADx assistance did not result in increased sensitivity of optical diagnosis. Despite a slight increase, the specificity of CADx-assisted diagnosis remained suboptimal. Olympus America Corporation served as the clinical study sponsor.

Computer-aided diagnosis improves characterization of Barrett’s neoplasia by general endoscopists (with video)

Characterization of visible abnormalities in patients with Barrett's esophagus (BE) can be challenging, especially for inexperienced endoscopists. This results in suboptimal diagnostic accuracy and poor interobserver agreement. Computer-aided diagnosis (CADx) systems may assist endoscopists. We aimed to develop, validate, and benchmark a CADx system for BE neoplasia. The CADx system received pretraining with ImageNet and then consecutive domain-specific pretraining with GastroNet, which includes 5 million endoscopic images. It was subsequently trained and internally validated using 1758 narrow-band imaging (NBI) images of early BE neoplasia (352 patients) and 1838 NBI images of nondysplastic BE (173 patients) from 8 international centers. CADx was tested prospectively on corresponding image and video test sets with 30 cases (20 patients) of BE neoplasia and 60 cases (31 patients) of nondysplastic BE. The test set was benchmarked by 44 general endoscopists in 2 phases (phase 1, no CADx assistance; phase 2, with CADx assistance). Ten international BE experts provided additional benchmark performance. Stand-alone sensitivity and specificity of the CADx system were 100% and 98% for images and 93% and 96% for videos, respectively. CADx outperformed general endoscopists without CADx assistance in terms of sensitivity (P= .04). Sensitivity and specificity of general endoscopists increased from 84% to 96% and 90% to 98% with CAD assistance (P< .001). CADx assistance increased endoscopists' confidence in characterization (P< .001). CADx performance was similar to that of the BE experts. CADx assistance significantly increased characterization performance of BE neoplasia by general endoscopists to the level of expert endoscopists. The use of this CADx system may thereby improve daily Barrett surveillance.

Performance of a novel computer-aided diagnosis system in the characterization of colorectal polyps, and its role in meeting Preservation and Incorporation of Valuable Endoscopic Innovations standards set by the American Society of Gastrointestinal Endoscopy.

There has been an increasing role of artificial intelligence (AI) in the characterization of colorectal polyps. Recently, a novel AI algorithm for the characterization of polyps was developed by NEC Corporation (Japan). The aim of our study is to perform an external validation of this algorithm. The study was a video-based evaluation of the computer-aided diagnosis (CADx) system. Patients undergoing colonoscopy were recruited to record videos of colonic polyps. The frozen polyp images extracted from these videos were used for real-time histological prediction by the endoscopists and by the CADx system, and the results were compared. A total of 115 polyp images were extracted from 66 patients. Sensitivity, negative predictive valueand accuracy for diminutive polyps on white light imaging (WLI) and image-enhanced endoscopy (IEE) when assessed by CADx was 90.9% [95% confidence interval (CI) 77.3-100] and 95.8% [95% CI 87.5-100], 80% [95% CI 44.4-97.5] and 90.9% [95% CI 58.7-99.8], 84.8% [95% CI 72.7-97] and 84.6% [95%CI 71.8-94.9], respectively, compared to 48.1% [95%CI 37.7-59.1] and 72% [95% CI 62.5-81], 37.5% [95% CI 28.8-46.8] and 55% [95% CI 44.7-65.0], 53.7% [95% CI 44.2-63.2] and 66.7% [95% CI 59.7-73.3] when assessed by endoscopists. Concordance between histology and CADx-based post-polypectomy surveillance intervals was 93.02% on WLI and 96% on IEE. AI-based optical diagnosis is promising and has the potential to be better than the performance of general endoscopists. We believe that AI can help make real-time optical diagnoses of polyps meeting the Preservation and Incorporation of Valuable endoscopic Innovations standards set by the American Society of Gastrointestinal Endoscopy.

Development and validation of artificial neural networks model for detection of Barrett’s neoplasia: a multicenter pragmatic nonrandomized trial (with video)

The aim of this study was to develop and externally validate a computer-aided detection (CAD) system for the detection and localization of Barrett's neoplasia and assess its performance compared with that of general endoscopists in a statistically powered multicenter study by using real-time video sequences. In phase 1, the hybrid visual geometry group 16-SegNet model was trained by the use of 75,198 images and videos (96 patients) of neoplastic and 1,014,973 images and videos (65 patients) of nonneoplastic Barrett's esophagus. In phase 2, image-based validation was performed on a separate dataset of 107 images (20 patients) of neoplastic and 364 images (14 patients) of nonneoplastic Barrett's esophagus. In phase 3 (video-based external validation) we designed a real-time video-based study with 32 videos (32 patients) of neoplastic and 43 videos (43 patients) of nonneoplastic Barrett's esophagus from 4 European centers to compare the performance of the CAD model with that of 6 nonexpert endoscopists. The primary endpoint was the sensitivity of CAD diagnosis of Barrett's neoplasia. In phase 2, CAD detected Barrett's neoplasia with sensitivity, specificity, and accuracy of 95.3%, 94.5%, and 94.7%, respectively. In phase 3, the CAD system detected Barrett's neoplasia with sensitivity, specificity, negative predictive value, and accuracy of 93.8%, 90.7%, 95.1%, and 92.0%, respectively, compared with the endoscopists' performance of 63.5%, 77.9%, 74.2%, and 71.8%, respectively (P< .05 in all parameters). The CAD system localized neoplastic lesions with accuracy, mean precision, and mean intersection over union of 100%, 0.62, and 0.54, respectively, when compared with at least 1 of the expert markings. The processing speed of the CAD detection and localization were 5 ms/image and 33 ms/image, respectively. To our knowledge, this is the first study describing external (multicenter) validation of AI algorithms for the detection of Barrett's neoplasia on real-time endoscopic videos. The CAD system in this study significantly outperformed nonexpert endoscopists on real-time video-based assessment, achieving >90% sensitivity for neoplasia detection. This result needs to be validated during real-time endoscopic assessment.

Endoscopic resection of large Paris 0-Ip pedunculated polyps: video demonstration of recent U.S. Multi-Society Task Force recommendations on resection and removal for general endoscopists.

Video 1Illustration of general principles as well as different techniques that can be used for the ligation and resection of pedunculated polyps.

Tu1046 EFFECT OF AN EDUCATIONAL POLYPECTOMY WORKSHOP ON CHOICE OF TOOL UTILIZED BY GENERAL ENDOSCOPIST DURING COLONOSCOPY

Optimal removal of diminutive (<5mm) polyps (DP) has been evaluated in multiple studies. Studies have compared and shown that polyp removal via cold snare polypectomy (CSP) is superior to removal via jumbo biopsy forceps (JBF), especially for DP measuring 4-5mm. Despite this, many general endoscopists still utilize JBF as the standard approach for DP removal. Our study sought to determine if a polypectomy educational session would increase the rate of CSP among general endoscopists. General endoscopists at a tertiary care center underwent an educational session discussing the optimal methods of polyp removal, followed by a hands-on laboratory session. Participants underwent surveys analyzing comfort regarding removal of polyps before and immediately after the session. Changes in polypectomy practice was analyzed by looking at random 2 week intervals of all colonoscopies performed by general endoscopists prior to, immediately after, and 6 months after the educational session was completed. Endoscopy notes were retroactively analyzed to gather data on number of polyps removed, polyp size, method of removal, and patient characteristics. Chi Square analysis was utilized to compare the change in polypectomy method across the three time points. 17 general endoscopists underwent the education session. Surveyed participants experienced a small subjective improvement in comfort using CS for removal of polyps and with removal of flat polyps less than 10mm. 218 colonoscopy patients (54.9% female) were evaluated before (n=97), immediately after (n=83), and 6 months after (n=88) the polypectomy seminar. There was no significant difference between age, BMI, prep quality, and polyp size amongst groups. There was a significant increase in CS compared to JBF use for the removal of ≥ 4mm polyps immediately after the session (p=0.0008 using Bonferroni-adjusted p-value). There was an insignificant decline in the proportion of CS use at 6 months post intervention compared to immediately-after the workshop (p=0.108). When broken down further, the proportion of 4mm polyps removed with a CS rather than JBF significantly increased immediately after the educational session and was sustained at 6 months post intervention (p=0.0004). There was no significant change in rates of CS use for 5mm polyps, although data showed it was used >90% of the time prior to the educational intervention (p=0.1420). An educational session with didactic and hands-on components appears to be an effective way to increase proportion of CS use for DP removal at a tertiary care center, thereby likely improving resection margins. Further studies will evaluate if these results remain sustained and if this session would be of benefit to endoscopists in a community setting.Proportion of cold snare compared to jumbo biopsy forceps utilization in polypectomy for polyps 4-5mm in size.View Large Image Figure ViewerDownload Hi-res image Download (PPT)

Deep-Learning System Detects Neoplasia in Patients With Barrett’s Esophagus With Higher Accuracy Than Endoscopists in a Multistep Training and Validation Study With Benchmarking

We aimed to develop and validate a deep-learning computer-aided detection (CAD) system, suitable for use in real time in clinical practice, to improve endoscopic detection of early neoplasia in patients with Barrett's esophagus (BE). We developed a hybrid ResNet-UNet model CAD system using 5 independent endoscopy data sets. We performed pretraining using 494,364 labeled endoscopic images collected from all intestinal segments. Then, we used 1704 unique esophageal high-resolution images of rigorously confirmed early-stage neoplasia in BE and nondysplastic BE, derived from 669 patients. System performance was assessed by using data sets 4 and 5. Data set 5 was also scored by 53 general endoscopists with a wide range of experience from 4 countries to benchmark CAD system performance. Coupled with histopathology findings, scoring of images that contained early-stage neoplasia in data sets 2-5 were delineated in detail for neoplasm position and extent by multiple experts whose evaluations served as the ground truth for segmentation. The CAD system classified images as containing neoplasms or nondysplastic BE with 89% accuracy, 90% sensitivity, and 88% specificity (data set 4, 80 patients and images). In data set 5 (80 patients and images) values for the CAD system vs those of the general endoscopists were 88% vs 73% accuracy, 93% vs 72% sensitivity, and 83% vs 74% specificity. The CAD system achieved higher accuracy than any of the individual 53 nonexpert endoscopists, with comparable delineation performance. CAD delineations of the area of neoplasm overlapped with those from the BE experts in all detected neoplasia in data sets 4 and 5. The CAD system identified the optimal site for biopsy of detected neoplasia in 97% and 92% of cases (data sets 4 and 5, respectively). We developed, validated, and benchmarked a deep-learning computer-aided system for primary detection of neoplasia in patients with BE. The system detected neoplasia with high accuracy and near-perfect delineation performance. The Netherlands National Trials Registry, Number: NTR7072.

Development and validation of the international Blue Light Imaging for Barrett's Neoplasia Classification

Detecting subtle Barrett's neoplasia during surveillance endoscopy can be challenging. Blue-light imaging (BLI) is a novel advanced endoscopic technology with high-intensity contrast imaging that may improve the identification of Barrett's neoplasia. The aim of this study was to develop and validate the first classification to enable characterization of neoplastic and non-neoplastic Barrett's esophagus using BLI. In phase 1, descriptors pertaining to neoplastic and non-neoplastic Barrett's esophagus were identified to form the classification, named the Blue Light Imaging for Barrett's Neoplasia Classification (BLINC). Phase 2 involved validation of these component criteria by 10 expert endoscopists assessing 50 BLI images. In phase 3, a web-based training module was developed to enable 15 general (nonexpert) endoscopists to use BLINC. They then validated the classification with an image assessment exercise in phase 4, and their pre- and post-training results were compared. In phase 1 the descriptors were grouped into color, pit, and vessel pattern categories to form the classification. In phase 2 the sensitivity of neoplasia identification was 96.0% with a very good level of agreement among the experts (κ= .83). In phase 3, 15 general endoscopists completed the training module. In phase 4 their pretraining sensitivity (85.3%) improved significantly to 95.7% post-training with a good level of agreement (κ= .67). We developed and validated a new classification system (BLINC) for the optical diagnosis of Barrett's neoplasia using BLI. Despite the limitations of this image-based study with a high prevalence of neoplasia, we believe it has the potential to improve the optical diagnosis of Barrett's neoplasia given the high degree of sensitivity (96%) noted. It is also a promising tool for training in Barrett's esophagus optical diagnosis using BLI.

An Interactive Web-Based Educational Tool Improves Detection and Delineation of Barrett’s Esophagus–Related Neoplasia

Endoscopic detection of early Barrett's esophagus-related neoplasia (BORN) is a challenge. We aimed to develop a web-based teaching tool for improving detection and delineation of BORN. We made high-definition digital videos during endoscopies of patients with BORN and non-dysplastic Barrett's esophagus. Three experts superimposed their delineations of BORN lesions on the videos using special tools. In phase one, 68 general endoscopists from 4 countries assessed 4 batches of 20 videos. After each batch, mandatory feedback compared the assessors' interpretations with those from experts. These data informed the selection of 25 videos for the phase 2 module, which was completed by 121 new assessors from 5 countries. A 5-video test batch was completed before and after scoring of the four 5-video training batches. Mandatory feedback was as in phase 1. Outcome measures were scores for detection, delineation, agreement delineation, and relative delineation of BORN. A linear mixed-effect model showed significant sequential improvement for all 4 outcomes over successive training batches in both phases. In phase 2, median detection rates of BORN in the test batch increased by 30% (P < .001) after training. From baseline to the end of the study, there were relative increases in scores of 46% for detection, 129% for delineation, 105% for agreement delineation, and 106% for relative delineation (all, P < .001). Scores improved independent of assessors' country of origin or level of endoscopic experience. We developed a web-based teaching tool for endoscopic recognition of BORN that is easily accessible, efficient, and increases detection and delineation of neoplastic lesions. Widespread use of this tool might improve management of Barrett's esophagus by general endoscopists.

Advanced Training of Gynecologic Surgeons and Incidence of Intraoperative Complications after Total Laparoscopic Hysterectomy: A Retrospective Study of More Than 2000 Cases at a Single Institution

Study ObjectiveTo investigate whether surgeon factors including level of training undertaken in laparoscopic surgery, time in specialist practice, and case volume were associated with surgical morbidity for total laparoscopic hysterectomy (TLH). DesignA retrospective cohort study (Canadian Task Force classification II-2). SettingA tertiary care setting in Western Australia. PatientsTwo thousand thirteen patients who underwent TLH for benign or malignant indications. InterventionsWomen undergoing TLH were allocated to 1 of 3 groups of surgeons: general gynecologists, gynecologic endoscopists, and subspecialists. Measurements and Main ResultsAll patients undergoing elective TLH at St John of God Subiaco Hospital, Subiaco, Perth, Western Australia, between January 1, 2011, and December 31, 2016, were included for analysis. Variables recorded included cystotomy, ureteric injury, enterotomy/colostomy, bowel serosa injury, vascular injury, conversion to laparotomy, return to the operating room, hemorrhage, blood transfusion, operating time, length of stay, and postoperative complications to 42 days. The primary outcome was any major intraoperative complication. The incidence of any major intraoperative complication was 1.8% (36/2013 cases). Forty-five patients (2.2%) had a postoperative complication, and 74 (3.7%) patients were readmitted to the hospital after discharge. The incidence of any major intraoperative complication was significantly higher among general gynecologists compared with subspecialists (3.3% vs 1.1%, p = .002). No association was found between time in specialist practice and the incidence of major intraoperative complications (p = .629). A significant association for major intraoperative complications was observed for surgeons who had performed <100 laparoscopic hysterectomies during the study period (p = .032). ConclusionIn this study, despite a higher level of surgical acuity and the performance of additional and more complex procedures, surgical morbidity was lower in patients undergoing TLH by gynecologic surgeons with a higher level of subspecialist training.

Endoscopic Sphincterotomy for Sphincter of Oddi Dysfunction: Inefficacious Therapy for a Fictitious Disease

Endoscopic Sphincterotomy for Sphincter of Oddi Dysfunction: Inefficacious Therapy for a Fictitious Disease

The accuracy of polyp assessment during colonoscopy in FIT-screening is not acceptable on a routine basis.

Background: During colonoscopy, correct assessment of polyps is important. Recognition of early carcinomas is needed for tailor-made treatment and avoidance of unnecessary complications. Moreover, accurate diagnosis of diminutive lesions could result in a safe resect and discard strategy. We assessed the accuracy of polyp assessment by general endoscopists without specific training or experience in image-enhanced endoscopy during routine colonoscopies within a fecal immunochemical test (FIT)-based screening program. Methods: Data were collected in the third round of a FIT-based colorectal cancer screening pilot program. Patients diagnosed as FIT-positive (318) underwent colonoscopy using Olympus (160 and 180 series) endoscopes without magnification or routine use of (virtual) chromoendoscopy. Endoscopists received no special training. They made an on-site evaluation and classified detected polyps as hyperplastic, adenoma, carcinoma. Samples of resected lesions were sent for histopathology. Sensitivity and specificity were calculated. We differentiated for fellows and consultants. Results: In the 318 patients with a positive FIT-screening result, 683 lesions were detected; 564 lesions were included in the analyses. The pathologist classified these lesions as 141 hyperplastic polyps, 349 adenomas, 16 carcinomas, and 58 other. Sensitivity for diagnosis of adenomas was 88 % (95 %CI 84 – 91); specificity 49 % (95 %CI 42 – 55). Of the 16 colorectal carcinomas, endoscopists diagnosed four incorrectly (sensitivity 75 % [95 %CI 44 – 89]; specificity 99 % [95 %CI 98 – 100]), including three stage I cancers and one stage III cancer. There were no differences in accuracy of diagnosis that related to different sizes of lesions or the experience of the endoscopist. Conclusion: In a routine FIT-based screening setting and without specific training or routine use of (digital) chromoendoscopy, endoscopic prediction of the histopathology of colonic lesions is inaccurate when the procedure is performed by general endoscopists.

Endoscopy management algorithms: role of cyanoacrylate glue injection and self-expanding metal stents in acute variceal haemorrhage

Mortality from acute variceal bleeding (AVB) has improved markedly over the last 2–3 decades due to increased specialisation and standardisation of medical and endoscopic practice culminating in the production of...

EFFICACY OF NOVEL SB KNIFE JR EXAMINED IN A MULTICENTER STUDY ON COLORECTAL ENDOSCOPIC SUBMUCOSAL DISSECTION

Secure manipulation of forceps in endoscopic submucosal dissection (ESD) for colorectal tumors is sometimes hindered by the characteristics of that organ. SB knife Jr, which are scissor forceps using a mono-pole high frequency, were developed to avoid the difficulty of ESD operation in the colorectum. The aim of the present study was to examine the effectiveness of the SB knife Jr in colorectal ESD in 11 hospitals, mostly in northeastern Japan. One hundred and two colorectal tumors (49 non-granular laterally spreading tumor [LST] lesions, 39 granular LST lesions and 14 other lesions) that were resected by ESD operations using SB knife Jr between October 2009 and March 2010. All tumors (102/102) were resected en bloc and could be observed in detail. The mean size of the resected pieces was 40.3 mm. The mean operation time was 54.2 min. Of the complications, one case of micro-perforation occurred during the manipulation of submucosal dissection, and this case was treated with clips in that operation. The rates of resection carried out only with SB knife Jr were 74.5% (76/102). The novel ESD using SB knife Jr in the colorectum offers a breakthrough in resection techniques for not only expert endoscopists but also general endoscopists.

Barrett's esophagus: A historical perspective, an update on core practicalities and predictions on future evolutions of management

Interpretation of exploding knowledge about Barrett's esophagus is impaired by use of several conflicting definitions. Because any histological type of esophageal columnar metaplasia carries risk for esophageal adenocarcinoma, the diagnosis of Barrett's esophagus should no longer require demonstration of intestinal-type metaplasia. Endoscopic recognition and grading of Barrett's esophagus remains a significant source of ambiguity. Reflux disease is a key factor for development of Barrett's esophagus, but other factors must underlie its development, since it occurs in only a minority of reflux disease patients. Neither antireflux surgery nor proton pump inhibitor (PPI) therapy has major impacts on cancer risk. Within a year, a major trial should indicate whether low-dose aspirin usefully reduces cancer risk. The best referral centers have transformed the accuracy of screening and surveillance for early curable esophageal adenocarcinoma by use of enhanced and novel endoscopic imaging, visually-guided, rather than blind biopsies and by partnership with expert pathologists. General endoscopists now need to upgrade their skills and equipment so that they can rely mainly on visual targeting of biopsies on mucosal areas of concern in their surveillance practice. General pathologists need to greatly improve their interpretation of biopsies. Endoscopic therapy now achieves very high rates of cure of high-grade dysplasia and esophageal adenocarcinoma with minimal morbidity and risk. Such results will only be achieved by skilled interventional endoscopists. Esophagectomy should now be mainly restricted to patients whose cancer has extended into and beyond the submucosa. Weighing risks and benefits in the management of Barrett's esophagus is difficult, as is the process of adequately informing patients about their specific cancer risk.

A Survey of Sedation Practices for Colonoscopy in Canada

There are limited data regarding the use of sedation for colonoscopy and concomitant monitoring practices in different countries. A survey was mailed to 445 clinician members of the Canadian Association of Gastroenterology and 80 members of the Canadian Society of Colon and Rectal Surgeons in May and June 2009. Sixty-five per cent of Canadian Association of Gastroenterology members and 69% of Canadian Society of Colon and Rectal Surgeons members responded with the full survey. Most endoscopists reported using sedation for more than 90% of colonoscopies. The most common sedation regimen was a combination of midazolam and fentanyl. Propofol, either alone or with another drug, was used in 12% of cases. A higher proportion (94%) of adult gastroenterologists who routinely used propofol were highly satisfied compared with those using other sedative agents (45%; P<0.001). Fifty per cent of adult gastroenterologists and 29% of surgeons who were not currently using propofol expressed interest in starting to use it for routine colonoscopies. Only a single nurse was present in the endoscopy room during colonoscopy performed by two-thirds of the endoscopists. Results of the present survey suggest that gastroenterologists in Canada use sedation for colonoscopy in more than 90% of their patients. There was higher satisfaction among gastroenterologists who used propofol routinely for all colonoscopies. Most endoscopy rooms were staffed by a single nurse, which may limit further increases in the use of propofol. Further studies are needed to determine optimal staffing of endoscopy units with and without the use of propofol. Sedation practices of general surgery endoscopists need to be evaluated.

Endoscopic Submucosal Dissection Using Mucosectome for Adenocarcinoma of Esophagogastric Junction and Gastric Cardia

Introduction: Endoscopic submucosal dissection (ESD) procedure using IT knife, Hook knife, Flex knife, etc. has already reported and it is actually useful for En-bloc resection to some expert endoscopists of it, but sometimes difficult for general endoscopists to use it safely. When the target lesion is located at esophagogastric junction(EGJ) or gastric cardia(GC), ESD is quite difficult to carry out because the risk of complications such as bleeding and perforation is higher than the lesions at gastric body and antrum. The wall of EGJ and GC are thinner, and more thick vessels exist under the mucosa compared with gastric body and antrum. Therefore, surgery is the standard treatments for neoplasms located on EGJ and GC in many Japanese hospitals. We developed a safe and easy technique of the ESD using a new device (Mucosectome, Pentax Japan), and we have displayed our ESD technique for early esophageal caners using Mucosectome in DDW2006. This year, We studied our ESD method for superficial neoplasm located on EGJ and GC. Aims & Methods: Seventy-five lesions of superficial adenocarcinoma located on EGJ and GC were treated with ESD between July 2002 and September 2007 at Okayama university hospital and Tsuyama central hospital. Adenocarcinoma located on EGJ was defined as “true cardiac cancer (Type II)” and GC was defined as “subcardial gastric cancer (TypeIII)” according to Siewert's classification. We diagnosed “curative resection” based on the histological assessment after performing ESD; the lateral and vertical margins were free, differentiated type and mucosal or submucosal (less than 500 m from the musclaris mucosa) invasion. After ESD, the patients revealed “curative resection” usually underwent upper gastrointestinal endoscopy annually. For the patients revealed “non-curative resection”, surgical resection was carried out basically. In those patients, en-bloc resection rate, complications, curative resection rate, and procedure tine were evaluated. Results: En-bloc resection rate was 96%. Perforation occurred in two patients (1.3%) and both cases were managed conservatively by hemoclip. The average of the maximum size of resected specimen was 55.0 mm, and the average of the size of lesions was 13.5 mm. Sixty-five lesions (86.7%) were judged as “curative resection”. Four patients invaded more than 500 m in the submucosal layer were diagnosed as “non-curative resection” and underwent additional surgical resections. The maximum proceduer time was 180 minutes and the median of procedure time was 65 minutes. Conclusion: ESD using Mucosectome is useful and safe method for adenocarcinoma of esophagogastric junction and gastric ca.

RISK MANAGEMENT TO PREVENT PERFORATION DURING ENDOSCOPIC SUBMUCOSAL DISSECTION

En bloc resection is beneficial for accurate histological assessment of resected specimens of endoscopic mucosal resection. Conventional endoscopic mucosal resection is simple and convenient but with this procedure the size of specimen obtained from one‐piece resection is very limited. Endoscopic submucosal dissection (ESD) using IT knife, Hook knife, Flex knife and so on has already been reported and it is useful to some expert endoscopists, but sometimes difficult for general endoscopists to use safely. The drawback of ESD is that it is difficult and is consequently associated with a higher rate of perforation, which may reach up to 2–6% . In addition, ESD requires advanced endoscopic techniques. Further improvement of devices and techniques is expected to be developed to prevent perforation for ESD procedure.

Endoscopic Full-Thickness Resection (EFTR) with Sutured Closure of Defect: Wedge Resection for Gastric Tumours

Endoscopic Full-Thickness Resection (EFTR) with Sutured Closure of Defect: Wedge Resection for Gastric Tumours Keiichi Ikeda, Paul Swain, Sandy Mosse, Tim Mills, Hisao Tajiri, Annette Fritscher-Ravens Background: Tumours, which extend into the deep submucosa or proximal muscularis propria or further, might be advantageously staged and treated by full thickness resection if secure methods for performing the procedure and closing the defect were available. Full thickness resection would allow more complete histological examination of the cancer and allow less-invasive removal of more deeply penetrating cancers, which have not spread to the serosal surface. A method for rapid closure of full thickness defects in the stomach wall would be valuable for other flexible endosurgical applications. Aims: 1. To test the feasibility of full thickness gastric wedge resection and defect closure. 2. To develop methods for suturing full thickness defects or perforations in the stomach. Materials and Methods: A new sewing method was developed using a flexible sheathed needle with a metal tag and thread at the tip, which passes through the accessory channel. Prototype cutting and knot-tying devices closed the defect after full-thickness resection. Full-thickness wedge resection was achieved by two methods. 1. Aspiration method using a ligating device without submucosal injection with subsequent snare removal. 2. A circumferential cutting method using an insulated tip knife. They were studied in survival experiments in pigs (n=10). A check endoscopy was performed at 7 days after the procedure and again at 21-28 days with subsequent retrieval of the healed defect for further examination at postmortem. At the time of the last endoscopy the EFTR procedure was repeated. Tests of water-tightness and measurements of the force required to pull out the stitches were performed at post-mortem. Results: It was possible to take full-thickness wedge resections from the gastric wall (100%: 20/20) and close the defect after resection using sewing, cutting and knot-tying devices (100%: 20/20). Water tightness at the suturing site was confirmed in experiment at postmortem (100%: 10/10). A healing ulcer at the suturing site was evident at follow-up endoscopy in experiment with survival pigs. The pullout force with stitches using this new sewing method was significantly higher than with endoscopic clips (20.3NG 0.94 vs. 2.2G 0.42, p ! 0.05). There were no serious complications during these experiments. Conclusion: Full-thickness gastric wedge resection with sutured defect closure was feasible and appeared safe in these survival experiments. New methods of sutured defect closure are presented. 221 Novel Procedure of Endoscopic Submucosal Dissection (ESD) Using a New Device (MUCOSECTOME) Yoshiro Kawahara, Atsushi Imagawa, Shigeatsu Fujiki, Yasushi Shiratori Backgrounds: En-bloc resection is beneficial for accurate histological assessment of resected specimen of Endoscopic mucosal resection (EMR). Variable EMR methods were developed. Conventional EMR technique or technique using Cap device method (EMRC) is technically simple and convenient but with this procedure the size of specimen obtained from one-piece resection is very limited. Endoscopic submucosal dissection (ESD) procedure using IT knife, Hook knife, Flex knife, etc. has already reported and it is actually useful to some expert endoscopists of it, but sometimes difficult for general endoscopists to use it safely. We developed a safe and easy technique of the ESD using a new device (Mucosectome, Prototype, Pentax Japan). Device and Methods: Mucosectome is an electrosurgical device, which is newly developed for ESD. Mucosectome is composed with flexible plastic shaft and cutting wire. Traction applied on the handle manipulates the tip of the Mucosectome to assist in the proper alignment of the cutting wire to the tissue. Plastic shaft moves a muscular layer side; cutting wire moves a mucosal layer side of the submucosa during ESD, and then procedure itself becomes safe. Results: 65 cases of early gastric cancer and 5 cases of early esophageal cancer patients received ESD using Mucosectome. En-bloc resection of the lesion succeeded in 67 cases. Dissection of the submucosa was very easily and quickly carried out. Minor bleeding including oozing occurred in 9.8% and no perforation encountered. Conclusion: Here we present a new method of ESD using Mucosectome, which can realize safer, easier, and less time-consuming ESD compared to previous methods. By using this device, general endoscopists may also be able to performe ESD safely.

Novel Procedure of Endoscopic Submucosal Dissection (ESD) Using a New Device (MUCOSECTOME)

Backgrounds: En-bloc resection is beneficial for accurate histological assessment of resected specimen of Endoscopic mucosal resection (EMR). Variable EMR methods were developed. Conventional EMR technique or technique using Cap device method (EMRC) is technically simple and convenient but with this procedure the size of specimen obtained from one-piece resection is very limited. Endoscopic submucosal dissection (ESD) procedure using IT knife, Hook knife, Flex knife, etc. has already reported and it is actually useful to some expert endoscopists of it, but sometimes difficult for general endoscopists to use it safely.