Training model for teaching endoscopic submucosal dissection of gastric tumors

Novel gastric endoscopic submucosal dissection training model enhances the endoscopic submucosal dissection skills of trainees: a multicenter comparative study

BACKGROUND

Endoscopic submucosal dissection (ESD) requires high endoscopic technical skills, and trainees should develop effective training methods. In collaboration with KOTOBUKI Medical, we developed the G-Master, which is a non-animal training model that can simulate various parts of gastric ESD. We aimed to clarify the usefulness of the G-Master for inexperienced ESD trainees.

METHODS

We collected data from the first 5 gastric ESD cases conducted by 15 inexperienced ESD trainees at 5 participating centers between 2018 and 2022. The participants were divided into two groups: the G-Master training and non-G-Master training groups. Outcome measurements, such as procedural speed, perforation rate, self-completion rate, and en bloc resection rate, were compared between the two groups retrospectively.

RESULTS

A total of 75 gastric ESD cases were included in this study. The G-Master training group included 25 cases performed by 5 trainees, whereas the non-G-Master training group included 50 cases performed by 10 trainees. The median procedural speed for all cases was significantly faster in the G-Master training group than in the non-G-Master training group. Moreover, the procedural speed was linearly improved from the initial to the last cases in the lower location in the G-Master training group compared with the non-G-Master training group. In addition, although there was no significant difference, the G-Master training group showed lower rates of perforation and a lesser need to transition to expert operators than the non-G-Master training group.

CONCLUSION

The G-Master could improve the ESD skills of inexperienced ESD trainees.

Development of new gastric endoscopic submucosal dissection training model: A reproducibility evaluation study

Background and study aims  Gastric endoscopic submucosal dissection (ESD) is a highly technical procedure mainly due to the distinctive shape of the stomach and diverse locations of lesions. We developed a new gastric ESD training model (G-Master) that could accurately recreate the location of the stomach and assessed the reproducibility of located lesions in the model. Methods  The model comprises a simulated mucous membrane sheet made of konjac flour and a setting frame, which can simulate 11 locations of the stomach. We assessed the reproducibility of each location in the model by assessing the procedure speed and using a questionnaire that was distributed among experts. In the questionnaire, each location was scored on a six-point scale for similarity of locations. Results  The mean score for all locations was high with > 4 points. Regarding locations, lower anterior and posterior walls had medium scores with 3 to 4 points. The procedure speed was slower in the greater curvature of the upper and middle gastric portions, where ESD is considered more difficult than the overall procedure speed. Conclusions  The new gastric ESD training model appears to be highly reproducible for each gastric location and its application for training in assuming actual gastric ESD locations.

Training Simulators for Gastrointestinal Endoscopy: Current and Future Perspectives

Simple Summary

Over the last decades, visual endoscopy has become a gold standard for the detection and treatment of gastrointestinal cancers. However, mastering endoscopic procedures is complex and requires long hours of practice. In this context, simulation-based training represents a valuable opportunity for acquiring technical and cognitive skills, suiting the different trainees’ learning pace and limiting the risks for the patients. In this regard, the present contribution aims to present a critical and comprehensive review of the current technology for gastrointestinal (GI) endoscopy training, including both commercial products and platforms at a research stage. Not limited to it, the recent revolution played by the technological advancements in the fields of robotics, artificial intelligence, virtual/augmented reality, and computational tools on simulation-based learning is documented and discussed. Finally, considerations on the future trend of this application field are drawn, highlighting the impact of the most recent pandemic and the current demographic trends.

Abstract

Gastrointestinal (GI) endoscopy is the gold standard in the detection and treatment of early and advanced GI cancers. However, conventional endoscopic techniques are technically demanding and require visual-spatial skills and significant hands-on experience. GI endoscopy simulators represent a valid solution to allow doctors to practice in a pre-clinical scenario. From the first endoscopy mannequin, developed in 1969, several simulation platforms have been developed, ranging from purely mechanical systems to more complex mechatronic devices and animal-based models. Considering the recent advancement of technologies (e.g., artificial intelligence, augmented reality, robotics), simulation platforms can now reach high levels of realism, representing a valid and smart alternative to standard trainee/mentor learning programs. This is particularly true nowadays, when the current demographic trend and the most recent pandemic demand, more than ever, the ability to cope with many patients. This review offers a broad view of the technology available for GI endoscopy training, including platforms currently in the market and the relevant advancements in this research and application field. Additionally, new training needs and new emerging technologies are discussed to understand where medical education is heading.

Simulating Surgical Skills in Animals: Systematic Review, Costs & Acceptance Analyses

Background: Modern surgery demands high-quality and reproducibility. Due to new working directives, resident duty hours have been restricted and evidence exists that pure on-the-job training provides insufficient exposure. We hypothesize that supplemental simulations in animal models provide a realistic training to augment clinical experiences. This study reviews surgical training models, their costs and survey results illustrating academic acceptance.

Methods: Animal models were identified by literature research. Costs were analyzed from multiple German and Austrian training programs. A survey on their acceptance was conducted among faculty and medical students.

Results: 915 articles were analyzed, thereof 91 studies described in-vivo animal training models, predominantly for laparoscopy (30%) and microsurgery (24%). Cost-analysis revealed single-training costs between 307€ and 5,861€ depending on model and discipline. Survey results illustrated that 69% of the participants had no experience, but 66% would attend training under experienced supervision. Perceived public acceptance was rated intermediate by medical staff and students (4.26; 1–low, 10 high).

Conclusion: Training in animals is well-established and was rated worth attending in a majority of a representative cohort to acquire key surgical skills, in light of reduced clinical exposure. Animal models may therefore supplement the training of tomorrow's surgeons to overcome limited hands-on experience until virtual simulations can provide such educational tools.

Evaluation of Eleview® Bioadhesive Properties and Cushion-Forming Ability

Submucosal injection is generally required for both endoscopic-mucosal resection (EMR) and submucosal dissection (ESD). SIC-8000 (Eleview®) is a new liquid composition in the form of a microemulsion for submucosal injection, approved by the Food and Drug Administration (FDA) 510(k) and Conformité Européene (CE) marked, containing a biocompatible polymer as a cushioning agent. The aim of this study was to evaluate Eleview®’s performance in terms of bioadhesive properties and cushion-forming ability. The bioadhesion was evaluated by measuring the interaction between Eleview® and the extracellular matrix (the main component of the submucosal layer) using the texture analyzer. To better comprehend the mechanism of action of Eleview® after submucosal injection, force of detachment and adhesion work were measured for the following formulations: Eleview®, Eleview® without poloxamer (functional polymer), poloxamer solution alone, normal saline, and MucoUp® (competing product on the Japanese market). The results obtained show the interaction between Eleview® and the extracellular matrix, highlighting the stronger bioadhesive properties of Eleview® compared with Eleview® without poloxamer, poloxamer solution alone, as well as normal saline and MucoUp®. The ability of Eleview® to form a consistent and long-lasting cushion in situ, once injected into the submucosal layer, was tested ex vivo on a porcine stomach. The results obtained show a better permanence in situ for the product compared with normal saline injection and to MucoUp® (t-test, p < 0.05).

Hemorrhage control during gastric endoscopic submucosal dissection: Techniques using uncovered knives

Since the last decade, endoscopic submucosal dissection (ESD) has been used as the standard treatment for superficial gastrointestinal neoplasms. Trainees learning ESD frequently encounter difficulties such as vascularity, peristalsis, and fibrosis during the procedure. Because individual vascularity differs, it generally cannot be consistently avoided. Given that massive hemorrhages can prolong the procedure time and diminish treatment efficacy and that insufficient vessel handling may also increase postoperative bleeding, hemorrhage control during ESD becomes important to ensure procedure safety. This article discusses methods for controlling hemorrhage during gastric ESD. Endoscopists should have a basic understanding of the vascular architecture and the high‐density areas in blood vessels, which are susceptible to intraoperative hemorrhage. Efficient preventative coagulation should be performed in addition to mastering the techniques for hemorrhage control using hemostatic forceps. Techniques useful for preventing intraoperative hemorrhage at every step (e.g. submucosal injection, mucosal incision, and dissection) should be learned. Gaining procedural competence and learning hemorrhage control techniques not only during ESD but also in daily work would help provide safe and effective treatment.

Endoscopic submucosal dissection: a cognitive task analysis framework toward training design

BACKGROUND

One of the major impediments to the proliferation of endoscopic submucosal dissection (ESD) training in Western countries is the lack of sufficient experts as instructors. One way to address this gap is to develop didactic systems, such as surgical simulators, to support the role of trainers. Cognitive task analysis (CTA) has been used in healthcare for the design and improvement of surgical training programs, and therefore can potentially be used for design of similar systems for ESD.

OBJECTIVE

The aim of the study was to apply a CTA-based approach to identify the cognitive aspects of performing ESD, and to generate qualitative insights for training.

MATERIALS AND METHODS

Semi-structured interviews were designed based on the CTA framework to elicit knowledge of ESD practitioners relating to the various tasks involved in the procedure. Three observations were conducted of expert ESD trainers either while they performed actual ESD procedures or at a training workshop. Interviews were either conducted over the phone or in person. Interview participants included four experts and four novices. The observation notes and interviews were analyzed for emergent qualitative themes and relationships.

RESULTS

The qualitative analysis yielded thematic insights related to four main cognition-related categories: learning goals/principles, challenges/concerns, strategies, and decision-making. The specific insights under each of these categories were systematically mapped to the various tasks inherent to the ESD procedure.

CONCLUSIONS

The CTA approach was applied to identify cognitive themes related to ESD procedural tasks. Insights developed based on the qualitative analysis of interviews and observations of ESD practitioners can be used to inform the design of ESD training systems, such as virtual reality-based simulators.

USEFULNESS OF GASTRIC SUBMUCOSAL DISSECTION DEPTH TO EVALUATE SKILL ACQUIREMENT IN SHORT TERM TRAINING COURSES IN ESD: AN EXPERIMENTAL STUDY

BACKGROUND

Endoscopic submucosal dissection (ESD) is a complex endoscopic procedure, with high rates of adverse events and technical difficulties. To overcome that problem, many training centers published the importance of animal models for skill acquirement in ESD. However, no study has used the submucosal dissection depth (DSUB) as a parameter to evaluate the learning curve in ESD, which might be a relevant factor since an optimal resection plane is important to achieve a curative resection and avoid intraoperative complications.

OBJECTIVE

This study aimed to assess ESD skill acquirement after short-term training sessions by evaluating the submucosal dissection depth (DSUB) and the association with adverse events.

METHODS

This experimental study included 25 experienced endoscopists in therapeuthic procedures (>5years) and 75 specimens resected by ESD (three resections / endoscopist). Learning parameters (resection time, size, en bloc resection rate, bleeding, perforation and submucosal dissection depth) were prospectively evaluated. The percentages of DSUB of all specimens resected were calculated.

RESULTS

All specimens were resected from the gastric body (n=75). The mean size of the resected specimens was 23.97±7.2 mm. The number of adverse events, including bleeding, perforation, and death, were 17 (22.67%), 3 (4%), and 0 cases, respectively. The average mean time by the third dissection decreased from 28.44±9.73 to 18.72±8.81 min (P<0.001). The proportion of DSUB in the bleeding and non-bleeding group were respectively 37.97%±21.13% and 68.66%±23.99%, indicating a significant association between DSUB and bleeding incidence (P<0.001). The ROC curve analysis indicated a cut-off point of 61% (sensitivity, 64%; specificity, 94%) of submucosal dissection depth associated with bleeding. Therefore, when ESD was performed at a depth of >61% of the submucosal layer, the risk for bleeding during the procedure decreased (PPV, 0.97; 95% CI, 0.85-0.99).

CONCLUSION

Improvement in the learning curve in ESD and a better cognitive ability were seen by the third dissection in these short term training courses. And a significant association between DSUB and the risk of bleeding.

Training in endoscopic mucosal resection and endoscopic submucosal dissection: Face, content and expert validity of the live porcine model

Introduction

Endoscopic mucosal resection and endoscopic submucosal dissection are demanding procedures. This study aims to establish face, content and expert validity of the live porcine model in performing endoscopic mucosal resection, endoscopic submucosal dissection, complication management and to assess it as a training tool.

Material and methods

Tutors and trainees participating in live porcine model endoscopic mucosal resection and endoscopic submucosal dissection workshops filled out a questionnaire regarding the realism of the model compared to human setting and its role as a learning tool. A 10-point Likert scale was used.

Results

Ninety-one endoscopists (13 tutors; 78 trainees) were involved in four workshops. Median global classifications for the realism of the life porcine model ranged between 7.0-8.0 (interquartile range 5.0-9.0). Procedures resembled human cases with a median of 9.0 (8.0-9.0) for oesophageal multiband endoscopic mucosal resection; 8.5 (8.0-9.0) for oesophageal endoscopic submucosal dissection; 9.0 (8.0-10.0) for gastric endoscopic submucosal dissection; and 9.0 (8.5-9.75 and 8.0-9.69) for complication detection and management. The animal model as a learning tool had median scores of 9.0 (7.0-10.0) considering how procedures are performed; 9.0-9.5 (8.0-10.0) for usefulness for beginners; and 9.0-10.0 (5.0-10.0) regarding it a prerequisite.

Conclusions

Training in a live porcine model was considered very realistic compared to the human setting and was highly appreciated as a learning tool. This is the first study to establish face, content and expert validity of the live porcine model in performing multiband endoscopic mucosal resection, oesophageal and gastric endoscopic submucosal dissection. The validation of this model provides the rationale to incorporate it into formal teaching programmes.

Innovations in surgery simulation: a review of past, current and future techniques

As a result of recent work-hours limitations and concerns for patient safety, innovations in extraclinical surgical simulation have become a desired part of residency education. Current simulation models, including cadaveric, animal, bench-top, virtual reality (VR) and robotic simulators are increasingly used in surgical training programs. Advances in telesurgery, three-dimensional (3D) printing, and the incorporation of patient-specific anatomy are paving the way for simulators to become integral components of medical training in the future. Evidence from the literature highlights the benefits of including simulations in surgical training; skills acquired through simulations translate into improvements in operating room performance. Moreover, simulations are rapidly incorporating new medical technologies and offer increasingly high-fidelity recreations of procedures. As a result, both novice and expert surgeons are able to benefit from their use. As dedicated, structured curricula are developed that incorporate simulations into daily resident training, simulated surgeries will strengthen the surgeon's skill set, decrease hospital costs, and improve patient outcomes.

Simulator training in gastrointestinal endoscopy - From basic training to advanced endoscopic procedures

Simulator-based gastrointestinal endoscopy training has gained acceptance over the last decades and has been extensively studied. Several types of simulators have been validated and it has been demonstrated that the use of simulators in the early training setting accelerates the learning curve in acquiring basic skills. Current GI endoscopy simulators lack the degree of realism that would be necessary to provide training to achieve full competency or to be applicable in certification. Virtual Reality and mechanical simulators are commonly used in basic flexible endoscopy training, whereas ex vivo and in vivo models are used in training the most advanced endoscopic procedures. Validated models for the training of more routine therapeutic interventions like polypectomy, EMR, stenting and haemostasis are lacking or scarce and developments in these areas should be encouraged.

Endoscopic submucosal dissection in the colorectum: Feasibility in the Canadian setting

Endoscopic submucosal dissection is a minimally invasive endoscopic technique for the removal of gastrointestinal tumours that is increasingly being used for colonic neoplasms to spare resection of colon in selected patients. Colonic endoscopic submucosal dissection is technically challenging and was initially pioneered in Japan but increasingly used in selected western centres. Its use in Canada is currently limited, and the authors review the challenges and opportunities, in addition to the unique training infrastructure required to practice the procedure under supervision. Specific tools are required to perform endoscopic submucosal dissection and meticulous attention to detail is essential. The authors provide a combined Japanese and Canadian perspective to this technique, and discuss training and performance of endoscopic submucosal dissection as well as potential indications.

ESD around the world: United States

Endoscopic submucosal dissection (ESD) is a well-established advanced mucosal resection technique used in Japan, where it originated, and some other Asian countries. The technical difficulty and potentially higher rates of significant complications have been obstacles for its dissemination across the United States, on top of the lack of available equipment, candidate lesions in the gastrointestinal tract, and adequate training programs. Yet American physicians are becoming increasingly aware of the benefits of ESD. Simplification of technique, modification of tools and materials, and improved availability of training opportunities are essential in order to accelerate the adoption of ESD in the United States.

High-pressure jet injection of viscous solutions for endoscopic submucosal dissection: a study on ex vivo pig stomachs

BACKGROUND

Long-lasting lifting is a key factor during endoscopic submucosal dissection (ESD) and can be obtained by water-jet injection of saline solution or by injection of viscous macromolecular solutions. Combination of the jet injection and the macromolecular viscous solutions has never been used yet. We assessed the ability of a new water-jet system to inject viscous solutions in direct viewing and in retroflexion. We compared jet injection of saline solution and hyaluronate 0.5 % to perform ESD on ex vivo pig stomachs in order to evaluate the benefits of macromolecular solutions when injected by a jet-injector system.

METHODS

This is a prospective comparative study in pig stomachs. Using the jet injector, four viscous solutions were tested: hydroxyethyl starch, glycerol mix, hyaluronate sodic (0.5 %), and poloxamer mix. Ten ESDs larger than 25 mm (five in direct viewing and five in retroflexion) and one larger than 10 cm were performed with each solution. ESD with hyaluronate jet injection was then compared with ESD with saline jet injection by performing 50 ESDs in each group. A single, minimally-experienced operator conducted all the procedures.

RESULTS

All 145 resections were complete, including all marking points with two perforations. Eleven jet ESDs per solution were conducted without any injection issue. In the second part of the study, when compared with saline, significant benefit of hyaluronate was observed on dissection speed (0.80 vs. 1.08 cm(2)/min, p < 0.001).

CONCLUSION

This is the first report on a jet-injector system allowing injection of macromolecular viscous solutions even with retroflexed endoscope. Jet injection of macromolecular solutions can speed up dissection in comparison with saline, and should now be tested on humans.

Training in endoscopic submucosal dissection

Endoscopic submucosal dissection (ESD) represents an important advancement in the therapy of early neoplastic gastrointestinal lesions by providing higher en-bloc curative resection rate with lower recurrence compared to endoscopic mucosal resection (EMR) and by sparing the involved organ and protecting patient's quality of life. Despite these advantages ESD is associated with long procedure times and a higher rate of complications, making ESD a challenging procedure which requires advanced endoscopic skills. Thus, there has been a recognized need for structured training system for ESD to enhance trainee experience and, to reduce the risks of complications and inadequate treatment. ESD has a very flat learning curve. However, we do not have uniformly accepted benchmarks for competency. Nevertheless, it appears that, in Japan, more than 30 supervised gastric ESD procedures are required to achieve technical proficiency and minimize complications. A number of training algorithms have been proposed in Japan with the aim to standardize ESD training. These algorithms cannot be directly applied in the West due to substantial differences including the availability of highly qualified mentors, the type of pathology seen, choice of devices, and trainee's background. We propose a training algorithm for Western physicians which integrates both hands-on training courses, animal model work as well as visits to expert centers. No specific preceptor training programs have been yet developed but there is a consensus that these programs are important for permeation of ESD worldwide.

Prevention and management of complications of and training for colorectal endoscopic submucosal dissection

Endoscopic submucosal dissection (ESD) is reported to be an efficient treatment with a high rate of en bloc resection for large colorectal tumors in Japan and some other Western and Asian countries. ESD is considered less invasive than laparoscopic colectomy. However, ESD carries a higher risk of perforation than endoscopic mucosal resection (EMR). Various devices and training methods for colorectal ESD have been developed to solve the difficulties. In this review, we describe the complications of colorectal ESD and prevention of those complications. On the other hand, colorectal ESD is difficult for less-experienced endoscopists. The unique step-by-step ESD training system is performed in Japan. Additionally, appropriate training, including animal model training, for colorectal ESD should be acquired before working on clinical cases.

Possibility of ex vivo animal training model for colorectal endoscopic submucosal dissection

PURPOSE

Colorectal endoscopic submucosal dissection (ESD) has not been standardized due to technical difficulties and requires extensive training for reliability. Ex vivo animal model is convenient, but has no blood flow. The objective of this study is to evaluate the characteristics of various ex vivo animal models including a blood flow model for colorectal ESD training and the usefulness of practicing endoscopic hemostasis and closure using an animal model.

METHODS

Harvested porcine cecum, rectum, and stomach and bovine cecum and rectum were analyzed regarding ease of mucosal injection, degree of submucosal elevation, and status of the proper muscle layer. Ex vivo animal model with blood flow was made using the bovine cecum. The vessel around the cecum was detached, and red ink was injected. Endoscopic hemostasis for perioperative hemorrhage and endoscopic closure for perforation were performed in this model.

RESULTS

Mucosal injection was easily performed in the bovine cecum and rectum. Submucosal elevation was low in the bovine cecum, while the proper muscle layer was not tight in the porcine rectum and bovine cecum. Endoscopic hemostasis were accomplished in six (60 %) out of ten procedures of the ex vivo blood flow model. In two non-experts, the completion rates of endoscopic closure were 40 and 60 % in the first five procedures. These rates became 100 % in the last five procedures.

CONCLUSIONS

We have evaluated the characteristics of various ex vivo animal models and shown the possibility of training for endoscopic hemostasis and endoscopic closure in the ex vivo animal model.

Stepwise training in rectal and colonic endoscopic submucosal dissection with differentiated learning curves

BACKGROUND

Endoscopic submucosal dissection (ESD) has revolutionized the resection of GI superficial neoplasms, but adoption in Western countries is significantly delayed.

OBJECTIVE

To evaluate a stepwise colorectal endoscopic submucosal dissection (ESD) learning and operative training protocol.

DESIGN

Prospective study in the Western setting.

SETTING

This study took place in a nonacademic hospital with one endoscopist expert in therapeutic endoscopy but novice in ESD.

PATIENTS

Indications for ESD were superficial neoplasms 20 mm and larger without ulcerations or fibrosis.

INTERVENTION

Training consisted of 5 unsupervised ESDs on isolated stomach, an observation period at an ESD expert Japanese center, 1 supervised ESD on isolated stomach, and retraining on 1 rectal ESD under supervision. The operative training on patients was performed without supervision moving from the rectum to the colon according to the competence achieved.

MAIN OUTCOME MEASUREMENTS

Competence was defined as an 80% en bloc resection rate plus a statistically significant reduction in operating time per square centimeter. Learning curves were calculated based on consecutive blocks of 5 procedures.

RESULTS

From February 2009 to February 2012, 30 rectal and 30 colonic ESDs were performed. The rectal ESD learning curve showed that the en bloc resection rate was 80% after 5 procedures (P = not significant); the operating time per square centimeter significantly decreased after 20 procedures (P = .0079); perforation occurred in 1 patient. The colonic ESD learning curve showed that the en bloc resection rate was 80% after 20 procedures (P = not significant); the operating time per square centimeter significantly decreased after 20 procedures (P = .031); perforations occurred in 2 patients.

LIMITATIONS

Single-center design.

CONCLUSIONS

A minimal intensive training seems sufficient for endoscopists expert in therapeutic procedures to take up ESD in a not overly arduous incremental method with separate and sequential learning curves for the rectum and colon.

ESD Hands-on Course Using Ex Vivo and In Vivo Models in South Korea

Endoscopic submucosal dissection (ESD) is an established treatment for gastric neoplasias especially in regions with a high volume of gastric cancer. Although ESD has many advantages over endoscopic mucosal resection, ESD is technically more difficult and can result in severe complications. Therefore establishment of an effective training system is required to help endoscopists climb the ESD learning curve. Although a standard training system for ESD remains to be established, some centers are incorporating ex vivo and/or in vivo animal models to provide a safe and effective means of ESD training. However, it is unknown if these animal models are more effective than other programs. Moreover the efficacy of the animal model may vary according to socio-economic status and the volume of gastric cancer. In this article we introduce the basic and advanced ESD training model using the ex vivo and in vivo animal model from South Korea and review the associated literature from other regions.

Ex vivo and in vivo models for endoscopic submucosal dissection training

Endoscopic submucosal dissection is a technically challenging but highly effective technique for the treatment of well selected early neoplasms in the digestive tract. Although it is frequently performed in East Asian countries, the Western world has not adopted this technique yet, probably due in part to the difficulty to learn it. Ex vivo and in vivo animal models are invaluable tools to overcome at least the beginning of the learning curve, although the initial step is the acquisition of basic knowledge about early diagnosis of neoplasias, and observing real procedures in expert centers. The practical issues, advantages, and disadvantages of the ex vivo and in vivo models are discussed.

Is transnasal endoscope-assisted endoscopic submucosal dissection for gastric neoplasm useful in training beginners? A prospective randomized trial

BACKGROUND

The main problem in performing endoscopic submucosal dissection (ESD) of gastric neoplasms is that it is technically difficult, especially for beginners.

METHODS

A total of 51 patients were randomly assigned to undergo transnasal endoscope-assisted or routine ESD performed by two endoscopists inexperienced in ESD while supervised by one expert.

RESULTS

Total procedure time (p = 0.330), complete resection rate (p = 0.977), and complication rate (p = 0.157) were similar for the patients who underwent transnasal endoscope-assisted and routine ESD, but bleeding control time was significantly longer in the transnasal endoscope-assisted ESD group (p = 0.002). Three and six patients in the transnasal endoscope-assisted and routine ESD groups, respectively, were "dropped out" during the procedures (p = 0.291). The endoscopists tended to regard the traction with the transnasal endoscope as more useful for large tumors (p = 0.062). Bleeding control in patients who underwent the transnasal endoscope-assisted ESD was significantly longer for patients with tumors located in the anterior wall, posterior wall, and lesser curvature of the stomach (p = 0.001).

CONCLUSION

Transnasal endoscope-assisted ESD does not result in improved outcomes when performed by beginners, except for some large tumors. The traction method used by beginners was not superior to proper supervision and advice by an expert during ESD and allowing the expert to perform the procedure when the risk of complications is high or the procedure is delayed.

Endoscopic submucosal dissection for removal of superficial gastrointestinal neoplasms: A technical review

Endoscopic submucosal dissection (ESD) is now the most common endoscopic treatment in Japan for intramucosal gastrointestinal neoplasms (non-metastatic). ESD is an invasive endoscopic surgical procedure, requiring extensive knowledge, skill, and specialized equipment. ESD starts with evaluation of the lesion, as accurate assessment of the depth and margin of the lesion is essential. The devices and strategies used in ESD vary, depending on the nature of the lesion. Prior to the procedure, the operator must be knowledgeable about the treatment strategy(ies), the device(s) to use, the electrocautery machine settings, the substances to inject, and other aspects. In addition, the operator must be able to manage complications, should they arise, including immediate recognition of the complication(s) and its treatment. Finally, in case the ESD treatment is not successful, the operator should be prepared to apply alternative treatments. Thus, adequate knowledge and training are essential to successfully perform ESD.

[Endoscopic submucosal dissection: only for expert endoscopists?]

Endoscopic submucosal dissection (ESD) can be applied to early gastrointestinal cancers. This technique was developed to achieve radical curative resection and to reduce unnecessary surgical interventions. ESD was designed in eastern countries and is not widely used in the West. Although ESD represents a major therapeutic advance in endoscopy and is performed with curative intent, the complication rate (hemorrhage, perforation) is higher than reported in other techniques, requiring from endoscopists the acquirement of technical skill and experience through a structured and progressive training program to reduce the morbidity associated with this technique and increase its potential benefits. Although there is substantial published evidence on the applications and results of ESD, there are few publications on training in this technique and a standardized training program is lacking. The current article aims to describe the various proposals for training, as well as the basic principles of the technique, its indications, and the results obtained, since theoretical knowledge that would guide endoscopists during the clinical application of ESD is advisable before training begins. Training in an endoscopic technique has a little value without knowledge of the technique's aims, the situations in which it should be applied, and the results that can be expected.

Ex vivo pig training model for esophageal endoscopic submucosal dissection (ESD) for endoscopists with experience in gastric ESD

BACKGROUND

Esophageal endoscopic submucosal dissection (ESD) has developed in recent years because of its high rate of en bloc resection. However, for many endoscopists, technical difficulty and risks of complications are great barriers to performing esophageal ESD. In this study, we developed an original training model for esophageal ESD using isolated pig esophagus and assessed this ex vivo model in endoscopists with experience in gastric ESD.

METHODS

Three endoscopists without experience in esophageal ESD but with some experience in gastric ESD performed esophageal ESD of artificial lesions in 10 consecutive sessions using this ex vivo model. The en bloc resection rate, operation time, number of muscularis propria layer injuries, and presence of perforation were recorded. We evaluated the effectiveness of this training in the three endoscopists by comparing results from the first five sessions (former period) with those from the last five sessions (latter period).

RESULTS

All three endoscopists achieved en bloc resections in all trials. In the former period, injury to the muscularis propria layer for each of the three endoscopists occurred a mean of 2.2 (1-3), 0.6 (0-1), and 3.2 (1-6) times, respectively. Perforation occurred in one session performed by one endoscopist. In the latter period, the mean number of muscularis propria layer injuries for each of the three endoscopists decreased to 0.2 (0-1), 0.2 (0-1), and 0.8 (0-2), respectively. The time of operation shortened from 35.0 (25-40), 36.4 (30-50), and 29.8 (23-43) min to 23.0 (16-31), 25.6 (23-28), and 29.2 (21-37) min, respectively.

CONCLUSIONS

This original ex vivo training model was helpful to endoscopists with experience in gastric ESD in acquiring the basic skills for performing esophageal ESD.

Experimental endoscopic submucosal dissection training in a porcine model: learning experience of skilled Western endoscopists

BACKGROUND

Endoscopic submucosal dissection (ESD) demands a new level of endoscopic skill in Europe. A 2-day workshop was set up for trainees to carry out five ESD each in order to obtain the skill level required to perform ESD in the stomach or rectum. This study describes: (i) the workshop setup; (ii) the participant's performance; and (iii) the training effect on post-workshop clinical ESD performance.

METHODS

Eighteen very experienced European endoscopists participated in four half-day (4.5 h) training sessions, with everybody rotating daily through six separate training stations (two each with dual, hook, or hybrid knives) with expert tutors. One anesthetized piglet was used per station and session. After 1 year, the clinical ESD performance was surveyed to estimate the training effect of the workshop.

RESULTS

Overall, 74 ESD were performed, that is, 4.1 ESD per participant. On average ESD lasted 57 min for 6 cm(2) specimens. We detected a 22% rate of perforation (16 of 74 ESD with perforations), mostly attributable to participants with less experience in ESD. Those who started clinical ESD within 1 year after the workshop performed 144 clinical ESD (median 8 [0-20] per trainee) mostly in the stomach (40%) and large bowel (46%) with an acceptable rate of perforation (9.7%) and surgical repair (3.5%) without mortality or persistent morbidity.

CONCLUSION

Intense skill training for ESD is needed to reduce the risk of perforation, as demonstrated by the results of this workshop. We show that experimental ESD training, however, enables skilled European endoscopists to perform ESD in standard locations with moderate risk of perforation during the clinical learning curve.

Endoscopic resection techniques and ablative therapies for Barrett’s neoplasia

Esophageal adenocarcinoma is the most rapidly increasing cancer in western countries. High-grade dysplasia (HGD) arising from Barrett’s esophagus (BE) is the most important risk factor for its development, and when it is present the reported incidence is up to 10% per patient-year. Adenocarcinoma in the setting of BE develops through a well known histological sequence, from non-dysplastic Barrett’s to low grade dysplasia and then HGD and cancer. Endoscopic surveillance programs have been established to detect the presence of neoplasia at a potentially curative stage. Newly developed endoscopic treatments have dramatically changed the therapeutic approach of BE. When neoplasia is confined to the mucosal layer the risk for developing lymph node metastasis is negligible and can be successfully eradicated by an endoscopic approach, offering a curative intention treatment with minimal invasiveness. Endoscopic therapies include resection techniques, also known as tissue-acquiring modalities, and ablation therapies or non-tissue acquiring modalities. The aim of endoscopic treatment is to eradicate the whole Barrett’s segment, since the risk of developing synchronous and metachronous lesions due to the persistence of molecular aberrations in the residual epithelium is well established.

Chicken soup for teaching and learning ESD

Endoscopic submucosal dissection (ESD) is becoming a popular procedure for the diagnosis and treatment of superficial mucosal lesions, and has the advantage of en bloc resection which yields a higher complete resection and remission rate compared to endoscopic mucosal resection (EMR). However, the learning process of this advanced endoscopic procedure requires a lengthy training period and considerable experience to be proficient. A well framed training protocol which is safe, effective, easily reproducible and cost-effective is desirable to teach ESD. In addition, the training course may need to be tailored around settings such as ethnicity, culture, workload, and disease incidence. In Asian countries with a large volume of early gastric lesions which need endoscopic treatment, endoscopists would be able to learn ESD expanding their skills from EMR to ESD under the supervision of experts. Whereas, in Western countries due to the low incidence of superficial gastric tumors, trials have utilized simulator models to improve learning. In Korea, the Korean Society of Gastrointestinal Endoscopy (KSGE) is playing an important role in training many gastroenterologists who have shown an interest in performing ESD by providing an annual live demonstration and a nationwide tutoring program. The purpose of this article is to introduce our ESD tutoring experience, review the published papers related to this topic, and propose several suggestions for future directions in teaching and learning ESD.

Worldwide experiences of endoscopic submucosal dissection: Not just Eastern acrobatics

The high incidence of gastric cancer has led to the initiation of cancer screening programs. As a result, the number of early gastric cancer cases has increased and consequentially, the cancer mortality rate has decreased. Moreover, the development of minimally invasive endoscopic treatment has been introduced for these early lesions. Endoscopic submucosal dissection (ESD) is now recognized as one of the preferred treatment modalities for premalignant gastrointestinal epithelial lesions and early gastric cancer without lymph node metastasis. We review the results of ESD including experiences in Japan and Korea, as well as western countries.

Endoscopic submucosal dissection with electrosurgical knives in a patient on aspirin therapy (with video)

BACKGROUND

The electrosurgical knives required to perform endoscopic submucosal dissection (ESD) have recently passed the 510(k) premarketing evaluation by the U.S. Food and Drug Administration and are now available for purchase in the United States. Challenges to ESD being more widely performed in the United States include the lack of intensive hands-on training programs and a low incidence of appropriate, highly dysplastic gastric lesions on which an ESD-trained endoscopist can begin performing this procedure in patients. Furthermore, there are no guidelines regarding the safety of continuing antiplatelet therapy in patients undergoing ESD.

OBJECTIVE

To report on the first gastric ESD performed in the United States by using recently approved electrosurgical knives on a patient who was maintained on aspirin therapy.

DESIGN

Case report.

SETTING

Large academic medical center.

PATIENT

One patient with a 2-cm high-grade dysplasia (HGD) lesion in the posterior antrum who had indwelling coronary stents and was maintained on aspirin therapy throughout the periprocedural period.

INTERVENTIONS

High-definition white-light and narrow-band imaging endoscopy, endosonography, and ESD by using recently approved electrosurgical knives.

MAIN OUTCOME MEASUREMENTS

Complete resection of the HGD gastric lesion.

RESULTS

En bloc complete resection of the HGD gastric lesion was achieved without any immediate or delayed bleeding or perforation. No residual or recurrent dysplasia was found on 1- or 3-month follow-up endoscopies.

LIMITATIONS

Generalizations cannot be made from this single case.

CONCLUSIONS

After receiving intensive hands-on training in both ex vivo and in vivo animal models, gastric ESD was successfully performed by 2 U.S. endoscopists by using recently approved electrosurgical knives in a patient maintained on aspirin therapy without any complications.

Endoscopic submucosal dissection training with pig models in a Western country

AIM: To test a strategy for endoscopic submucosal dissection (ESD) training in animal models designed to overcome the initial learning curve.

METHODS: ESD was attempted in ex vivo and in vivo pig models. Thirty ESD procedures were attempted in the esophagus (n = 9) or the stomach (n = 21). The ex vivo model was used until initial competence was achieved. In the in vivo model, several ESD procedures were performed in up to 3 sessions. The following variables were analyzed: specimen size, complete and en bloc resection rate, time for circumferential incision, time for submucosal dissection, total ESD duration, and complications.

RESULTS: Complete resection was achieved in 28 cases (en bloc 27); 2 could not be completed (one perforation, one technical difficulty). The mean ± SD time for circumferential incision was 36.2 ± 16.8 min (range: 8-87 min), and the mean ± SD time for submucosal dissection was 45.1 ± 35.7 min (range: 9-196 min). The mean ± SD size of the resected specimens was 45.2 ± 17.8 mm. The mean ± SD total resection time was significantly increased for the gastric cases performed in the first half of the study (n = 13) than in the second half (n = 8) (98.9 ± 62.4 min vs 61.7 ± 17.6 min, P = 0.04), although the specimen size did not differ.

CONCLUSION: Training in animal models could help endoscopists overcome the learning curve before starting ESD in humans.