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

Novel beagle model of gastric local fibrotic target lesions for the evaluation and training of endoscopic techniques

BACKGROUND

Novel endoscopic techniques used in the treatment of gastric lesions with local submucosal fibrosis need preclinical evaluation and training due to safety limitations. Therefore, the purpose of our study was to establish an animal model of gastric local fibrotic target lesions and assess its feasibility in the evaluation and training of endoscopic techniques.

METHODS

In six experimental beagles, a 50% glucose solution was injected into three submucosal areas of the fundus, body, and antrum of the stomach to create gastric local fibrotic target lesions (experimental group). On post-injection day (PID) 7, the injection sites were assessed endoscopically to confirm the presence of submucosal fibrosis formation, and the dental floss clip traction assisted endoscopic submucosal dissection (DFC-ESD) procedure was performed on the gastric local fibrotic target lesions to confirm its feasibility after endoscopic observation. The normal gastric mucosa of six control beagles underwent the same procedure (control group). All the resected specimens were evaluated by histological examination.

RESULTS

All 12 beagles survived without postoperative adverse events. On PID 7, 16 ulcer changes were observed at the injection sites (16/18) under the endoscope, and endoscopic ultrasonography confirmed the local submucosal fibrosis formation in all ulcer lesions. The subsequent DFC-ESD was successfully performed on the 32 gastric target lesions, and the mean submucosal dissection time in the ulcer lesions was greater than that in the normal gastric mucosa (15.3 ± 5.6 vs. 6.8 ± 0.8 min; P < 0.001). There was no difference in rates of en bloc resection, severe hemorrhage, or perforation between the two groups. Histological analysis of the ulcer lesions showed the absence of epithelial or muscularis mucosae and extensive submucosal fibrous tissue proliferations compared with normal gastric mucosa. Overall, endoscopists had high satisfaction with the realism and feasibility of the animal model.

CONCLUSION

We developed a novel animal model of gastric local fibrotic target lesions to simulate difficult clinical situations, which strongly appeared to be suitable for the preclinical evaluation and learning of advanced endoscopic techniques.

Endoscopic mucosal resection: tips and tricks for gastrointestinal trainees

Endoscopic mucosal resection (EMR) is a minimally invasive, specialized endoscopic technique that is useful in resecting superficial gastrointestinal lesions that are unable to be removed by standard polypectomy. This is typically accomplished using a submucosal injection that lifts the lesion away from the muscularis propria to allow for safe resection of the polyp, either via piecemeal or en bloc resection. Over the years, several techniques exist to perform EMR including conventional EMR or hot EMR, cold EMR and underwater EMR. Despite its established advantages and safety over conventional techniques such as surgery, the adoption of endoscopic resection (and thus the education and training of gastroenterology trainees) is lagging. The goal of this article is to offer a comprehensive review of the basic principles of colonic EMR. We review the concepts of optical diagnosis including the various polyp classification systems available to determine the polyp morphology and histology. We also discuss the technical aspects of performing colonic EMR. We also outline the common adverse events associated with EMR including bleeding, perforation, postpolypectomy syndrome, and residual or recurrent polyps, and discuss preventative measures that can be taken to mitigate adverse events. Lastly, we offer practical tips for trainees who want to undertake EMR in their clinical practice.

Training in esophageal peroral endoscopic myotomy (POEM) on an ex vivo porcine model: learning curve study and training strategy

BACKGROUND

Peroral endoscopic myotomy (POEM) is a very effective treatment for achalasia. However, training remains non-standardized. We evaluated a training curriculum, including ex vivo cases, followed by patients' cases under expert supervision. The objective was to establish a learning curve of POEM.

MATERIALS AND METHODS

Four operators having completed advanced endoscopy fellowship were involved. They had already observed > 30 cases performed by experts. They performed 30 POEMs standardized (tunnel and myotomy lengths) procedures on ex vivo porcine model. Procedural times, number/volume of injections, mucosal and serous perforations, and myotomy length were collected. The learning curve was assessed using dissection speed (DS) and a dedicated performance score (PS), including learning rate (LR) and learning plateau (LP).

RESULTS

The operators completed all cases within 4 months (median of 3.5 cases/week). The mean procedural time was 43.3 min ± 14.4. Mean myotomy length was 70.0 mm ± 15.6 mm. Dissection speed averaged 1.78 mm/min ± 0.78. Using DS and PS as parameter, the LR was reached after 12.2 cases (DS = 2.0 mm/min) and 10.4 cases, respectively. When comparing the LP and the plateau phase, the DS was slower (1.3 ± 0.5 mm/min versus 2.1 ± 0.54 mm/min, p < 0.005) and perforations were decreased: 0.35 ± 0.82 in LP vs. 0.16 ± 0.44 in PP. Following this training, all operators performed 10 supervised cases and are competent in POEM.

CONCLUSION

The association of observed cases and supervised ex vivo model training is effective for starting POEM on patients. The learning curve is 12 cases to reach a plateau.

Training in Endoscopic Submucosal Dissection in the United States: The Current Paradigm

Endoscopic submucosal dissection (ESD) training in Japan is pursued through a designated master-apprentice, organ-based stepwise training model. However, applying a similar program to the United States is not a practical strategy due to the significant differences in the training system and disease prevalence. To incorporate the ESD training into the current advanced endoscopy fellowship program, the use of recently developed techniques and technologies to improve the efficiency of ESD is ideal. The ESD training program in the United States should be prevalence-based, with increased involvement of trainees depending on their objectively assessed competency levels.

How to avoid overtreatment of benign colorectal lesions: Rationale for an evidence-based management

Implementing population-based screening programs for colorectal cancer has led to an increase in the detection of large but benign histological lesions. Currently, endoscopic mucosal resection can be considered the standard technique for the removal of benign lesions of the colon due to its excellent safety profile and good clinical results. However, several studies from different geographic areas agree that many benign colon lesions are still referred for surgery. Moreover, the referral rate to surgery is not decreasing over the years, despite the theoretical improvement of endoscopic resection techniques. This article will review the leading causes for benign colorectal lesions to be referred for surgery and the influence of the endoscopist experience on the referral rate. It will also describe how to categorize a polyp as complex for resection and consider an endoscopist as an expert in endoscopic resection. And finally, we will propose a framework for the accurate and evidence-based treatment of complex benign colorectal lesions.

Endoscopic submucosal dissection (ESD): how do Western endoscopists value animal models?

INTRODUCTION

Endoscopic Submucosal Dissection (ESD)was introduced in the West later than in the East. Our aim was to assess how Western endoscopists performing ESD have been trained and how they value animal models for training.

MATERIAL AND METHODS

An online survey regarding training in ESD was sent to Western endoscopists who published articles on advanced resection techniques.

RESULTS

From 279 endoscopists, 58 (21%) completed the questionnaire, of which 50 confirmed performance of clinical ESD. Endoscopists had a median of 15 years of endoscopic experience (IQR 9.75-20.25) and all of them were performing conventional EMR, before starting ESD. Prior to clinical ESD, 74% (n = 37) underwent training with ex vivo models, 84% (n = 42) with live animal models and 92% (n = 46) with at least, one of the two models. After starting clinical ESD, as trainers, 52% (n = 26) were involved with ex vivo and 60% (n = 30) with live animal models. Personal usefulness of ex vivo and live animal models was rated with a median of 9 (IQR 8-10) and 10 (IQR 8-10), out of 10, respectively. Courses with ex vivo and live animal models were considered a prerequisite before clinical practice by 84% (n = 42) and 78% (n = 39), respectively.

CONCLUSIONS

Western endoscopists have extensive endoscopic experience before starting ESD. The majority had pre-clinical training with ex vivo and live animal models and more than half are acting as trainers of other endoscopists with these models. Animal models are considered very useful and deemed a prerequisite before clinical practice by the majority of the endoscopists.

A novel postgraduate endoscopic course using a large animal model of secondary Crohn's disease stricture

BACKGROUND

The increasing complexity of advanced endoscopic techniques places a high demand on the endoscopist's expertise. Thus, live porcine models have been more frequently used for training. We briefly describe a hands-on postgraduate endoscopic course regarding a novel method of treatment of anastomotic strictures in a porcine model.

METHODS

The porcine model of Crohn's disease anastomotic stricture with two artificial side-to-side ileo-colonic anastomoses was used. Participants performed endoscopic stricturotomy under supervision at one of two equipped endoscopic stations. Available animals were endoscopically re-examined 3 months after the course.

RESULTS

Twelve anastomoses were prepared for the course. Eleven circumferential stricturotomies together with horizontal cut and clip placement were conducted. All anastomoses were passable for the scope after the procedure, and no case of perforation or bleeding occurred. All anastomoses available for re-examination remained passable for the endoscope after 3 months.

CONCLUSION

We successfully organised the first endoscopic hands-on course for the training of endoscopic stricturotomy on a large animal model.

A Template for Curriculum Development to Teach Complex Surgical or Endoscopic Techniques With Logistical Challenges

OBJECTIVE

The current, unprecedented pace of change in medicine challenges healthcare professionals to stay up-to-date. To more effectively disseminate new surgical or endoscopic techniques a modern paradigm of training is required. Our aim was to develop a curricular framework for complex techniques that provide logistical challenges to training in order to increase safe, effective use. We use colonic endoscopic submucosal dissection (cESD) as an example.

DESIGN

Curriculum development followed a multistep process representing best practice in training and education. First, a Clinical Needs Assessment established the demand for/sustainability of training. A Training Needs Analysis then identified the knowledge, skills, and attitudes required to perform cESD. A modified Delphi process defined desired learner characteristics, identified indications/contraindications to cESD, and developed a procedural task list. A pilot simulation program gathered feedback from cESD faculty experts and learners. Finally, a Behavioral Observation Scale was developed as a clinical assessment tool to assess procedural performance.

SETTING

The Houston Methodist Institute for Technology, Innovation and Education.

PARTICIPANTS

The first Curriculum Design Summit engaged 11 clinical SMEs, 4 education and training SMEs, 3 market development SMEs, and 1 medical device research and design engineer. The second Curriculum Design Summit engaged 10 clinical SMEs, 4 education and training SMEs, and 4 market development SMEs. We also engaged 12 Learner SMEs at both hands-on pilot courses who currently are training to perform cESD.

RESULTS

Desired learner criteria were defined (e.g., in practice >2 years, available case volume ≥25/year) to ensure ability and motivation of learners. Lesions were classified by (1) suitability for cESD (Clinical T1N0M0, Paris 0-IIa +1s  > 2 cm, 0-IIc + IIa, 0-IIc), and (2) suitability for trainee experience level. A comprehensive cESD task list was constructed and an assessment tool created based on SME review of key characteristics (e.g., comprehensiveness and usability).

CONCLUSION

We describe a comprehensive framework to develop educational curricula for complex surgical/endoscopic techniques with logistical challenges. To illustrate the sustainability of this training model and impact on patient outcomes, we plan to further develop and implement this program nationally.

Current status and trend in training for endoscopic submucosal dissection: A nationwide survey in Korea

BACKGROUND

Although endoscopic submucosal dissection (ESD) is widely used, the current status and trend in its training have yet to be fully evaluated. We aimed to investigate how ESD endoscopists have been trained in actual clinical practice.

METHODS

Endoscopists aged <45 years who have completed a gastroenterology fellowship or were currently in a fellowship for ≥2 years were included. We conducted a nationwide survey on the ESD training experiences of these endoscopists.

RESULTS

Among 79 young Korean endoscopists invited to participate in the survey, 68 (86.1%) trained in 24 major hospitals responded to the questionnaire. Twenty, 25, and 23 participants belonged to the second-year fellow, <5 years after training, and ≥5 years after training groups, respectively. Sixty-nine percent of the participants observed ≥50 ESD cases before starting ESD under supervision by an expert endoscopist. Additionally, 22% experienced ≥20 supervised ESDs during the training period. The proportion of the participants who underwent a hands-on course differed among the groups (≥5 years after training, 13.0%; <5 years after training, 40.0%; and second-year fellow, 50.0%; P = 0.027). ESD under supervision, observation, and hands-on course were the preferred methods for learning ESD (91.1%, 80.9%, and 35.3%, respectively). Overall, 42.6% of the participants were satisfied with their training program. More experience in supervised ESD (≥20 cases) was associated with an increased satisfaction (odds ratio, 6.65; 95% confidence interval, 1.62-36.31).

CONCLUSIONS

Observation and performance of ESD under the supervision of an expert endoscopist are the primary methods for learning ESD. Hands-on course program has been used more frequently in recent years.