Endoscopic Submucosal Dissection Experience Research Articles

S1243 Endoscopic Mucosal Resection and Endoscopic Submucosal Dissection Experience in Fourth Year Advanced Endoscopy Fellows

S1243 Endoscopic Mucosal Resection and Endoscopic Submucosal Dissection Experience in Fourth Year Advanced Endoscopy Fellows

Risk Factors Indicating Difficulty During Gastric Endoscopic Submucosal Dissection for Inexperienced Endoscopists: A Retrospective Study.

Factors that may make endoscopic submucosal dissection (ESD) difficult for operators have been evaluated according to results based on the performance of experienced endoscopists. This study aimed to verify the predictors of difficult gastric ESD for ESD beginners. From January 2015 to December 2021, 466 superficial gastric neoplasms were treated with ESD at Showa University Hospital. Excluding 103 lesions that performed ESD by experts who experienced more than 80 ESDs, a total of 363 lesions were included. The lesions were divided into two groups according to the ESD performance experience of the operator:ESD beginner (EB; ESD experience≤30 cases) and ESD intermediate (EI; ESD experience 31-80 cases) groups. Relationships between difficult ESD (having at least one of the following: procedure time>60 min, incomplete resection, change of operator, and occurrence of severe complications) and clinicopathological findings of the lesion were analyzed. The complete resection rates and the difficult ESD rates in the EB and EI groups were 99.3%, 94.8%, and 61.2%, 50.7%, respectively. In the EB group, univariate analysis showed that difficult ESD rate was significantly higher in the non-lower third lesions, the lesser curvature lesions, and cancerous lesions. In the EI group, univariate analysis showed that difficult ESD rate was significantly higher in lesion with ≥20 mm size, lesser curvature lesions, lesions with ulcers, and submucosal cancers. Multivariate analysis showed that the lesser curvature location and cancerous histology in the EB group and ≥20 mm lesion size, the lesser curvature location and submucosal invasion in the EI group were independent predictors of difficult ESD. The lesser curvature location is recognized as independent ESD difficulty factor for both beginners and intermediates.Cases with lesions located in the lesser curvature should not be selected for gastric ESD training by beginners.

Endoscopic enucleation of gastric choristoma in a child

Introduction. In pediatric practice, one may encounter various volumetric formations of the stomach, both benign and malignant. The verification and localization of the neoplasma is the most difficult issue in everyday work. Most often, benign tumors are represented by a rounded submucosal formation, covered with an intact mucous membrane. The most common formations that can be found in a child are leiomyomas. Objective is to present the first experience of endoscopic submucosal dissection and enucleation of the choristoma in a child. Clinical observation. The girl was admitted for inpatient treatment with complaints of prolonged (2 years) abdominal syndrome and mass formation of the antrum of the stomach. According to CT data, a voluminous soft tissue formation 8 × 7 × 12 mm in size was revealed in the antrum of the stomach, which does not accumulate a contrast agent. When performing esophagogastroduodenoscopy and endosonography, a submucosal formation of the prepyloric stomach was visualized, with dimensions of 7 × 10 mm. The macroscopic picture of the tumor corresponded to gastric leiomyoma. However, given the clinical picture, it was impossible to exclude the chorous stomach. Thus, the diagnosis was formulated: volumetric formation of the stomach. Leiomyoma? Choristoma? In the course of further treatment, surgical treatment was performed, in the amount of submucosal enucleation of the formation. According to the morphological study, the remote formation corresponded to the ectopic pancreatic tissue. Conclusion. Choristoma does not always have a “classic” appearance with retraction in the center, and the clinical picture is of great importance in the verification of neoplasma. Endoscopic submucosal removal of gastric choristoma is a minimally invasive and effective method of surgical treatment that can be used in children.

S1077 Novel Through the Scope Steerable Grasper Reduces Dissection Time and Technical Demand in Endoscopic Submucosal Dissection in Novice Endoscopists Compared to Clip and Line Traction Method: An Ex Vivo Randomized Study

Introduction: Lack of effective devices to aid in tissue traction to facilitate endoscopic submucosal dissection (ESD) leads to prolonged dissection time. Clip and line (CL) method is commonly used to provide traction and improve visualization of the submucosa. A novel through the scope dynamic steerable grasping arm (SGA) has recently been available. We aim to prospectively study the efficacy of this new device with novice endoscopists in an ex vivo setting. Methods: This is a prospective single center randomized trial. In an ex-vivo porcine stomach model, two 25mm circular lesions were marked. Submucosal injection using a lifting agent and circumferential incision was performed. Novice endoscopists with no prior experience of ESD and with one to three years of experience of performing endoscopies were randomized to either SGA (study group) or CL method (control group) first. Each endoscopists performed ESD with both methods. Primary outcome was total dissection time in minutes. Adverse events of muscle injury, perforation, mucosal injury or tissue fragmentation were noted. Participants were asked to choose their preferred traction method for future ESDs. Subsequently, NASA task load index was used to grade subjective mental and physical work load. Results: Ten subjects participated in the study and five were randomized to SGA method first. The mean dissection time was significantly shorter when using SGA compared to clip and line method (5.07 ± 2.19 mins vs 20.07 ± 8.45 mins, P< 0.001) irrespective of order of randomization. Four instances of muscle injury and one perforation were noted with CL and none with SGA. NASA task load index scores across the domains of mental demand (7.9 ± 3.1 vs 15 ± 4 , P< 0.001), physical demand (6.4 ± 2.5 vs 12.9 ± 5.6, P=0.009), temporal demand (5.6 ± 3.3 vs 13.8 ± 4.3, P< 0.001), performance (3.9 ± 3.2 vs 9.2 ± 5.0, P=0.02), effort (8.4 ± 3.5 vs 16.3 ± 2.8, P< 0.001) and frustration (3.9 ± 2.3 vs 14.3 ± 5.1, P< 0.001) were significantly lower with SGA compared to CL. All participants preferred SGA over CL method. Conclusion: With novice endoscopists performing ESD, SGA leads to faster dissection time compared to CL for traction with a reduced mental and physical work load. There was a trend towards reduced adverse events with SGA. SGA is a promising tool to improve efficiency and learning curve of ESD (Table). Table 1. - Dissection times between two methods across the two randomized groups Randomization Number of subjects Dissection time in minutes using SGA (mean +/- SD) Dissection time in minutes using CL (mean +/- SD) P value SGA first 5 5.32 + 2.21 22.6 + 11.42 0.017 CL first 5 4.82 + 2.41 17.5 + 3.70 0.002 Total 10 5.07 + 2.19 20.07 + 8.45 < 0.001 SGA: Steerable grasping arm; CL: Clip and line.

S1078 Are Advanced Endoscopy Fellows in the United States Achieving Adequate ESD Experience?

Introduction: In 2012, the American Society for Gastrointestinal Endoscopy (ASGE) established the official Advanced Endoscopy Fellowship (AEF) program match, supervised by the ASGE training committee, to serve as a platform connecting applicants and programs. Historically, advanced endoscopy fellowships offered endoluminal endoscopic procedures, including endoscopic retrograde cholangiopancreatography, endoscopic ultrasound, and endoscopic mucosal resection. To become designated as proficient, trainees needed to meet a minimum procedural volume. More recently, third space endoscopy procedures have evolved including endoscopic submucosal dissection (ESD) and peroral endoscopic myotomy (POEM). Multiple studies support that ESD proficiency requires a trainee perform a minimum of 50 gastric/esophageal as well as 50 colorectal dissections, for a total of at least 100 ESD procedures. We conducted a mirror study to reflect the present status of ESD training among the ASGE match programs. Methods: 2023 ASGE AEF programs were reviewed from publicly available information posted on the ASGE website. Results: Of the 78 AEF programs, 70 offer ESD training. The total number of ESD procedures per institution was 41.8±37 per year. Of these, the reported volume involving fellows’ hands-on experience was 17.8±24.6 procedures per year. The average number of physicians performing ESD was 1.4±0.7 per institution. Twenty-two of 70 programs perform >50 ESD procedures annually, with a median of 83.2±36.5 procedures per year. In these 22 programs, the fellows’ hands on experience was 33.3±34.5 procedures annually. Conclusion: ESD is an emerging endoscopic procedure for early GI tract malignancies. To be able to perform the procedure independently and safely, more than 100 supervised ESD procedures are required to achieve proficiency. Relative to other parts of the world, ESD in the United States is still an evolving procedural realm demanding close proctorship. Based on the current ASGE AEF data presented, a better understanding of the training process for ESD and third space endoscopy is necessary, with the potential development of standardized training requirements.

Endoscopic submucosal dissection for colorectal laterally spreading tumors: Clinical outcomes and predictors of technical difficulty.

We aimed to investigate the clinical outcomes of endoscopic submucosal dissection (ESD) for the treatment of colorectal laterally spreading tumors (LSTs) and the factors related to technical difficulty. Consecutive patients who underwent ESD for colorectal LSTs between June 2013 and January 2019 were retrospectively included. Factors associated with difficult ESD procedures (defined as conversion to piecemeal resection or discontinuation of endoscopic procedure), and dissection with a slow speed (<8 mm2 /min), were determined using the logistic regression analysis. A total of 325 patients with 342 colorectal LSTs (median size 20.0 mm) were enrolled. The proportions of granular (LST-G) and non-granular LST (LST-NG) were 62.9% and 37.1%, respectively. The overall en bloc and complete resection rates were 89.8% and 81.9%, respectively. The endoscopic procedure was discontinued in four lesions (1.2%), and 31 (9.1%) converted to piecemeal resection because of technical difficulty. Using multivariate analysis, positive non-lifting sign (odds ratio [OR] 19.9, P < 0.001), tumor size ≥20 mm (OR 10.0, P < 0.001), and less experienced endoscopists (OR 3.7, P=0.005) were independent factors for technically difficult procedure. Positive non-lifting sign (OR 3.7, P=0.004), lesion size <20 mm (OR 3.7, P < 0.001), LST-NG type (OR 1.8, P=0.034), and less colorectal ESD experience (OR 1.9, P=0.016) were independent factors of slow-speed dissection. ESD was feasible and safe for treating colorectal LSTs. Positive non-lifting sign and tumor ≥20 mm indicated difficult ESD procedures. Technical failure was more likely to occur in lesions resected by less-experienced endoscopists. Dissection speed might be improved with more experienced operators.

Single operator experience of endoscopic submucosal dissection for Barrett's neoplasia in a North American academic center.

ObjectivesEndoscopic submucosal dissection (ESD) is carving out an increasing role in the treatment of Barrett's associated neoplasia. ESD provides the advantage of en‐bloc resections and greater R0 resection rates. We aim to present outcomes from one of the largest single‐center cohorts of esophageal ESD in North America.MethodsAll patients undergoing esophageal ESD for Barrett's neoplasia between Oct 2016 and June 2020 at a Canadian tertiary care center were included. Demographic, procedural data, and lesion characteristics are presented. Subgroup analysis was performed on patients who underwent extensive resection (≥75% of esophageal circumference) and the patients who developed strictures.ResultsThirty‐four patients were included in the series. The median lesion diameter was 5.7 cm and the median procedure time was 129 min. The en‐bloc resection rate was 97%, and the R0 resection rate was 91%. Curative resection was achieved in 82% of patients. Upstaging in histology occurred in 59% of cases. Two adverse events occurred, and there were no perforations. Procedural outcomes were similar in patients with extensive resections, but those with ≥75% circumferential resection developed more strictures (65% vs. 6.3%, p < 0.01). Stricture formation was associated with extensive resection (odds ratio [OR]: 27.5, p < 0.01) and longer lesion diameter (OR: 1.7, p = 0.02).ConclusionOur experience with ESD for Barrett's related neoplasia shows excellent en‐bloc and R0 resection rate, and provides more accurate histological specimens. Curative resection is possible in the majority of cases, including those with extensive resections. Further investigation into stricture prophylaxis will be useful as near circumferential resections are attempted.

A Steep Early Learning Curve for Endoscopic Submucosal Dissection in the Live Porcine Model

Background: Endoscopic submucosal dissection (ESD) is a demanding procedure requiring high level of expertise. ESD training programs incorporate procedures with live animal models. This study aimed to assess the early learning curve for performing ESD on live porcine models by endoscopists without any or with limited previous ESD experience. Methods: In a live porcine model ESD workshop, number of resections, completeness of the resections, en bloc resections, adverse events, tutor intervention, type of knife, ESD time and size of resected specimens were recorded. ESD speed was calculated. Results: A total of 70 procedures were carried out by 17 trainees. The percentage of complete resections, en bloc resections and ESD speed increased from the first to the latest procedures (88.2%–100%, 76.5%–100%, 8.6–31.4 mm²/min, respectively). The number of procedures in which a trainee needed tutor intervention and the number of adverse events also decreased throughout the procedures (4 to 0 and 6 to 0, respectively). During the workshop, when participants changed to a different type of knife, ESD speed slightly decreased (18.5 mm²/min to 17.0 mm²/min) and adverse events increased again (0–2). Conclusions: Through successive procedures, complete resections, en bloc resections, and ESD speed improve whereas adverse events decrease, supporting the role of the live porcine model in the preclinical learning phase. Changing ESD knives has a momentarily negative impact on the learning curve.

Training program using a traction device improves trainees' learning curve of colorectal endoscopic submucosal dissection.

Colorectal endoscopic submucosal dissection (ESD) requires advanced endoscopic skill. For safer and more reliable ESD implementation, various traction devices have been developed in recent years. The purpose of this research was to evaluate whether an ESD training program using a traction device (TD) would contribute to the improvement of trainees' skill acquisition. The differences in treatment outcomes and learning curves by the training program were compared before and after the introduction of TD (control group: January 2014 to March 2016; TD group: April 2016 to June 2018). A total of 316 patients were included in the analysis (TD group: 202 cases; control group: 114 cases). The number of cases required to achieve proficiency in ESD techniques was 10 in the TD group and 21 in the control group. Compared to the control group, the TD group had a significant advantage in ESD self-completion rate (73.8% vs. 58.8%), dissection speed (19.5 mm2/min vs. 15.9 mm2/min), en bloc resection rate (100% vs. 90%), and R0 resection rate (96% vs. 83%). The rate of colorectal ESD self-completion by trainees improved immediately after the start of the training program using a traction device compared to the conventional method, and the dissection speed tended to increase linearly with ESD experience. We believe that ESD training using a traction device will help ESD techniques to be performed safely and reliably among trainees.

Construction of a novel predictive nomogram for difficult procedure of endoscopic submucosal dissection for colorectal neoplasms

Objectives To determine the predictors of difficult colorectal endoscopic submucosal dissection (ESD) and to develop a preoperative predictive model for difficult colorectal ESD procedures. Methods Colorectal neoplasms intended to be resected by ESD in our center between August 2013 and February 2019 were retrospectively enrolled. An ESD procedure which took more than 30 min, failed to remove the lesions en bloc or converted to surgery was defined as difficulty. Logistic regression analysis was conducted to find out the predictors of difficult ESD. A nomogram integrating independent predictors was developed and validated with respect to its discrimination, calibration and clinical application, using the receiver operating characteristic (ROC) curve, calibration plot and decision curve analysis (DCA), respectively. Results A total of 368 colorectal neoplasms in 355 patients were included. The independent predictors for difficult colorectal ESD were size ≥2 cm (odds ratio [OR] = 6.102, p < .001), positive non-lifting sign (OR = 6.569, p = .005), lesions located in left colon (OR = 2.475, p = .036) or rectum (OR = 2.183, p = .048), laterally spreading tumors (LSTs) (OR = 2.501, p = .008) and less colorectal ESD experience (≤20 cases) (OR = 2.3091, p = .028). The nomogram model incorporating the above predictors performed well in both of the training and validation sets (area under the cure [AUC] = 0.786 and 0.784, respectively). DCA demonstrated the clinical benefit of the nomogram was superior to that of each independent predictor alone. Conclusions The nomogram incorporating tumor size, location, morphology, non-lifting sign and ESD experience of operator can be conveniently used to facilitate the preoperative prediction of difficult colorectal ESD.

Scissor-type knife improves the safety of endoscopic submucosal dissection (ESD) among endoscopists without experience in ESD: a randomized ex vivo study.

Background and study aims Endoscopic submucosal dissection (ESD) is technically challenging, difficult to learn, and carries a substantial risk of perforation, all of which remain significant barriers to its adoptability. We aimed to determine whether use of a novel scissor-type knife improved efficacy and safety among novice performers of ESD. Materials and methods Following a brief didactic session on ESD, participants performed ESD of two lesions (2 cm diameter) in an ex vivo porcine gastric model. One resection was performed with a conventional knife and the other with the scissor knife (order of knife randomized). We recorded procedure time, successful en bloc resection, and adverse events (including full-thickness perforation and muscle injury) for each dissection. Participants completed a post-study survey. Results 10 endoscopists (8 trainees, 2 staff) considered novices in ESD participated. Compared with the conventional knife, use of the scissor knife was associated with a significantly shorter time to completion of submucosal dissection (mean 6.2 [SD 5.6] vs. 15.6 [SD 15.6] minutes; P = 0.04) and total procedure time was not significantly different (22.1 [SD 13.3] vs. 24.9 [SD 26.5] minutes; P = 0.65). Scissor knife use was also associated with a significantly lower proportion of perforation and/or muscle injury (10.0 % vs. 70.0 %; P < 0.01) and proportion of muscle injury alone (10.0 % vs. 60.0 %; P = 0.02). Conclusions Among novices performing ESD on an ex vivo animal model, use of a scissor knife was associated with a significantly lower proportion of adverse events without prolonging procedure time. Scissor-type knives may improve ESD safety, at least among novices.

Acquiring new complex endoscopic skills: Experience from the development of peroral endoscopic myotomy (POEM) in Malaysia.

Peroral endoscopic myotomy (POEM) has rapidly gained popularity as an effective treatment modality for achalasia. However, POEM services in the South East Asian region are not widely available due to either a lack of expertise or interest. In this article, we describe how a POEM service can be developed through a combination of networking with regional experts, having prior experience of endoscopic submucosal dissection (ESD), attending animal model workshops, collaborating with upper gastrointestinal surgeons, and working together in a multidisciplinary team. A total of 68 POEM procedures have been performed since 2015, with a 94.1% technical and 93.4% clinical success rate, and a 21.5% minor complication rate. We believe that our model may be useful for other Endoscopy Units in the region, which are performing advanced therapeutic endoscopy, to develop a POEM service too.

Endoscopic submucosal dissection is safe and feasible, allowing for ongoing surveillance and organ preservation in patients with inflammatory bowel disease

Experience of endoscopic submucosal dissection (ESD) for colorectal lesions in the setting of inflammatory bowel disease (IBD) remains limited. The aim of this work was to determine the safety, feasibility and oncological outcomes of ESD in patients with IBD. A retrospective review of all adult patients (≥18years) with a known diagnosis of either ulcerative colitis (UC) or Crohn's disease (CD) who underwent advanced colonoscopy and ESD between 1 January 2014 and 1 October 2020. Data collected included patient demographics, disease characteristics, pathological variables and procedure-related complication rates. A total of 25 patients were included: 19 (76%) were male with a median age of 63years and disease duration of more than 10years. Sixteen had UC and nine had CD; the majority were taking corticosteroids, immunomodulators or monoclonal antibodies at the time of ESD. The median procedure time was 41min and the majority (n=18; 72%) utilized chromoendoscopy. The median lesion size was 30mm: eight had low-grade dysplasia, nine had high-grade dysplasia and three had adenocarcinoma and underwent oncological resection. None had surgical intervention for complication of ESD or perforation. A total of 23 (88%) had a complete R0 resection. Over a median follow-up of 19months, three were found to have dysplasia excised in polyps and none had subsequent adenocarcinoma. ESD in the setting of IBD is safe and effective for complete removal of large neoplastic lesions, allowing for ongoing endoscopic surveillance and organ preservation rather than surgical intervention.

ID: 3527115 BEYOND THE LEARNING CURVE! LONG TERM OUTCOMES OF ENDOSCOPIC SUBMUCOSAL DISSECTION FOR COLORECTAL LESIONS: A LARGE COHORT FROM A U.S REFERRAL CENTER

Endoscopic submucosal dissection (ESD) has been widely adopted for the resection of early colorectal mucosal neoplasms (EMN) in Asia. However, Western countries lag far behind Asia and experience is limited, with literature primarily reporting technical success and safety. Here we present our colorectal ESD experience since 2010, including long-term follow-up results with >80% follow-up completion rate.

The learning experience for endoscopic submucosal dissection in a non-academic western hospital: a single operator's untutored, prevalence-based approach.

BackgroundStudies of learning experience in endoscopic submucosal dissection (ESD) commonly originate from the East. Little is known about the performance of ESD in low-volume western centers. Furthermore, it is unclear whether ESD can be self-taught without a tutored approach.MethodsWe performed a retrospective analysis of consecutive ESDs, performed in an untutored prevalence-based fashion by a single operator at a private Greek hospital from 2016-2020. Out of 60 lesions, standard ESD was applied for 54 and enucleation for 6; 41 were mucosal and 19 submucosal; 3 esophageal, 24 gastric, one duodenal, 12 colonic, and 20 rectal.ResultsPathology revealed carcinoma (n=14), neuroendocrine tumor (n=7), precancerous lesion (n=27), or other submucosal tumors (n=12). The rates of en bloc and R0 resection were 98% and 91%, respectively. The median resection speed was <3 cm2/h for the first 20 cases, but improved progressively to ≥9 cm2/h after 40 cases. Two patients underwent laparoscopic surgery for colonic perforation, and one received a blood transfusion because of delayed bleeding (serious adverse event rate: 5%). No deaths occurred. The median hospital stay was 1.3 days. Variables associated with improvement in ESD speed during the second period of the study were the application of countertraction and the experience acquired through other endosurgical techniques.ConclusionsESD was safe and effective in a low-volume center, with an acceptable adverse events rate. At least 40 mixed cases were needed to achieve a high resection speed. Additive experience gained through other endosurgical procedures probably contributed to the improvement in performance.

Real-World Experience of Endoscopic Submucosal Dissection for Ulcerative Colitis-Associated Neoplasia

Introduction: Patients with ulcerative colitis (UC) have an increased risk of colorectal cancer. Some studies have recently investigated endoscopic resection of UC-associated neoplasia (UCAN), but the indications for endoscopic resection of UCAN remain controversial. This study sought to clarify the problems encountered in endoscopic submucosal dissection (ESD) for UCAN. Methods: Seventeen lesions in 12 patients with UCAN (UCAN group) and 913 epithelial lesions in 824 control patients without UC (non-UC group) were evaluated. Both groups underwent ESD between January 2010 and December 2017 at Toranomon Hospital, Tokyo, Japan. Treatment outcomes of the 2 groups were compared retrospectively. Results: Univariate analysis showed that the mean tumor size was significantly smaller in the UCAN group than in the non-UC group (25.1 ± 26.7 mm vs. 31.9 ± 19.0; p = 0.0023); however, the R0 resection rate was significantly lower in the UCAN group (70.6 vs. 92.9%; p = 0.001). Multivariate analysis showed a significantly lower negative horizontal margin rate in the UCAN group (odds ratio 11.3, 95% confidence interval 3.588–34.525; p = 0.000). Discussion/Conclusion: ESD for UCAN is associated with a low-negative horizontal margin rate. When performing ESD for UCAN, it is important to evaluate the accuracy of the UCAN demarcation line, especially for flat lesions, using white-light imaging and chromoendoscopy as well as other modalities, including biopsy of surrounding tissues.

Endoscopic submucosal dissection comparing with surgical resection in patients with early gastric cancer – A single center experience in Taiwan

The choice of endoscopic submucosal dissection (ESD) as first line treatment for selected early gastric cancer (EGC) patients was proved as effective as surgical treatment in studies over many countries. Yet there is no such cohort comparison in Taiwan. This study is aimed to describe our experience in ESD treated EGC and to compare the outcomes with those underwent surgical treatment. This was a retrospective cohort study reviewing the patients with EGC underwent ESD and surgical treatments in a single tertiary referral center in Taiwan. The primary endpoint was disease specific survival. Recurrence free survival and length of hospital stay were also compared. The disease specific survival between indicated ESD and surgery showed no significant difference (cumulative survival 100% vs. 97.03%, p=0.39), so as the recurrence free survival (cumulative survival 92.31% vs. 94.06%, p=0.60). In subgroup analyses of ESD treated patients, a non-significant recurrence rate difference between indicated and non-indicated ESD was found (cumulative recurrence 7.69% vs. 20%, p=0.39) and a higher recurrence rate in patients with non-R0 resection compared with R0 resection (cumulative recurrence 0% vs. 40%, p<0.01). However, the shorter duration of hospital stay in ESD group was noted in comparison to surgery (mean 5.67 days vs. 15.75 days, p<0.01). The ESD patients have minor complications including bleeding, perforation and fever than surgery. ESD is a reasonable first line treatment in selected early gastric cancer in additional to surgery. Pre-treatment evaluation and post-ESD review of curability is crucial to further surveillance program or definite therapy including surgery.

Mo1779 CLINICAL ANALYSIS OF COLORECTAL ESD CARRIED OUT BY ENDOSCOPISTS LACKING EXPERIENCE IN GASTRIC ESD

Objective: Colorectal endoscopic submucosal dissection (ESD) is now carried out mainly by endoscopists with sufficient experience in gastric ESD. However, the detection rate of early gastric carcinoma is still low in China and endoscopic maneuverability differs between the stomach and colorectum. The aim of this study was to assess the feasibility of colorectal ESD carried out by endoscopists with no or little experience in gastric ESD. A total of 120 colorectal ESD cases, composed of each endoscopist’s who had no or <5 cases of experience in gastric ESD first 60 consecutive cases, were retrospectively reviewed. The endoscopists who participated in the present study had completed over 3000 colonoscopy and 500 colorectal EMR. They had inspected and learned from other endoscopists’ ESD procedures for more than 50 cases and undergone training using resected pig stomachs to get experience of basic ESD skills. We analyzed demographic data of patients, characteristics of lesions, procedure time, complete resection rate, en bloc resection rate and complication rate, et al. All cases were divided into three groups: the first 20 cases of each endoscopist were in early phase group, 21-40 cases were in middle phase group and 41-60 cases were in late phase group. All data were compared among three groups. There were 65 (54.2%) male and 55 (45.8%) female in these 120 cases. The average age was 63.5±12.4 years old. The rate of LST (82/120,68.3%) and lesion in rectum (52/60, 43.3%) were the highest. The size of non-SMT group was 2.28±1.01 cm, while SMT lesions was 0.70±0.16 cm. The average procedural time was 60.5+61.7 min. The en bloc resection and complete resection rates were 74.2% and 71.7%, respectively. 1 case suffered from hemorrhage after ESD and 8 cases of perforation occurred during ESD. However, no patients needed endoscopy again or surgery. According to learning curve, procedural time was significant longer in early phase compared with middle and late phases(P=0.000). Other data did not have significant difference among early, middle and late phases (P>0.05). Endoscopists who lack experience in gastric ESD can carry out colorectal ESD safely based on rigorous training, including enough colonscopy cases, inspecting colorectal ESD and excercising using resected pig stomachs. The procedural time could be shorten after 20 cases.

A Single-Center Early Experience of Endoscopic Submucosal Dissection for Gastric Lesions in Thailand.

Endoscopic submucosal dissection (ESD) was also considered a “high risk” at the starting point with skillful endoscopic techniques and terrible complications. Still, it remains challenging yet has become widespread among institutes in many parts of the world. This study is aimed at further investigating the feasibility, efficacy, and safety of ESD of gastric lesions and at evaluating clinical outcomes in early experience. The patient characteristics, postoperative outcomes, and results of histopathological examinations were reviewed retrospectively between January 2017 and May 2019. Thirteen patients' gastric ESD were included with all of en bloc resections without recurrence. The long duration was related to the large lesion, the upper part of the stomach, and previous treatment. In this study, the ESD procedure of the stomach is a feasible and safe minimally invasive treatment option with organ preservation. It requires training and experience with a learning approach where skill may be improved to prevent unwanted complications.

936 Endoscopic Submucosal Dissection as a Salvage Therapy After Failed Endoscopic Mucosal Resection for Colorectal Lesions: A Single Center Experience

INTRODUCTION: There is limited data in efficacy of Endoscopic Submucosal Dissection (ESD) as a salvage therapy after failed Endoscopic Mucosal Resection (EMR) attempt leading to scar tissue formation. We present a single center experience of ESD in evaluating safety and efficacy of ESD in treatment of colorectal lesions with failed prior attempt of EMR. METHODS: All patients who had ESD for colorectal lesions after prior unsuccessful attempt of removal by EMR, from 1/2013 to 12/2018 were included. Patient and procedure related data points were collected. Technical success was defined as successful completion of ESD to remove colonic lesions and clinical success was defined as complete removal of colonic lesions with negative margins. RESULTS: A total of 19 patients were included. The average age was 68.3 ± 7.5 years, 53% (10/19) patients were female. 10 patients had right sided, 2 patients had left sided and 7 patients had rectal lesions. The average size of the lesion was 3.9 ± 2.5 cm. 10 patients (53%) had en bloc resection and 9 patients (47%) had piecemeal resection despite ESD due to scar tissue formation from prior EMR attempt. Technical success of ESD was 100%. The average duration of the procedure was 103.5 ± 48 minutes. Complications occurred in 2 cases (10.5%), both had En bloc resection. One patient developed bleeding requiring endoscopic treatment and another patient developed microperforation managed conservatively. Of resected lesions, there were 9 tubular adenomas, 5 sessile serrated adenoma, 1 Tubulovillous adenoma, 1 neuroendocrine tumor and 3 samples with histology showing tubular adenoma but with positive margins for adenocarcinoma. ESD specimen added the diagnosis of carcinoma. All of the patients with en bloc resection had negative peripheral margins while of 9 patients who had piecemeal resection, 3 patients had positive margins for carcinoma. Thus clinical success of ESD was 84%. 2 of these patients required surgery while 1 was lost to follow up. Out of 16 patients with initial successful ESD, 13 patients had follow up for average 24 months without any recurrence (3 patients were lost to follow up). A trainee was involved in 60% of the procedures. CONCLUSION: ESD is a safe and effective method of diagnosis and treatment for colorectal lesions as a salvage therapy after failed EMR with overall low complication rates and low recurrence rates. ESD should be considered in centers of expertise prior to referring patients for surgical approach.