Introduction

Gastric endoscopic submucosal dissection (ESD) has become increasingly popular worldwide as a less invasive curative treatment for early gastric cancer. However, ESD requires highly endoscopic technical skills, and it is important for trainees to develop effective training methods for ESD. ESD training is generally conducted using extracted porcine digestive tracts, but there are several issues regarding ethics, costs, infection, and logistics. In collaboration with KOTOBUKI Medical, we have developed the G-Master, a training model that can simulate ESD in several locations in the stomach. Since G-Master uses plant-derived mucous membrane sheet, there is no contamination and training can be easily performed using endoscope units and devices that are commonly used in clinical practice. Although the G-Master has enabled pre-training before actual ESD at facilities that have adopted it, it is unclear whether it contributes to the improvement of endoscopic technical skills of trainees. In this study, we clarified the usefulness of the G-Master training for inexperienced ESD trainees.

Aims & Methods

The ESD data were collected for the first through fifth gastric ESD cases performed from March 2018 through February 2022 by 15 ESD-inexperienced endoscopists at five participating centers. The ESD data were divided into two groups, one with G-Master training and one without G-Master training and the endpoints were compared retrospectively. The endpoints were procedure speed, perforation rate, operator changing rate, and en bloc resection rate, endoscopists experiences, and clinicopathological features. The resection speed was calculated as the resected area of the specimen divided by the procedure time (mm2/min). The group with G-Master training was defined as the group of trainees who always had at least one ESD training session with G-Master before each ESD. The group without G-Master training was defined as the group of trainees who had never done G-Master ESD training.

Results

A total of 75 gastric ESD cases were enrolled, with 25 cases in the group with G-Master training performed by 5 ESD-inexperienced endoscopists and 50 cases in the group without G-Master training performed by 10 ESD-inexperienced endoscopists. There was no difference between the two groups in endoscopists experiences including the years after graduation from medical school, the number of esophagogastroduodenoscopies and colonoscopies performed, and clinical features of gastric ESD cases including the location or size. In the group with G-Master training, the median procedure speed for all cases was significantly faster (with vs without G-Master: 13.1 mm2/min vs. 8.1 mm2/min, p>0.001). And the procedure speed of the training group was linearly improved from the initial to the last cases (with vs without G-Master: initial case; 11.8 mm2/min vs 8.5 mm2/min, last case; 23.1 mm2/min vs 12.0 mm2/min). Additionally, the rates of perforation (0 case (0%) vs 1 case (2%)) and operator change to expert (5 cases (20%) vs 15 cases (30%)) were lower. There was no difference in en bloc resection rate between the two groups.

Conclusion

It was suggested that performing G-Master training before actual ESD could improve the endoscopic technical skills of trainees who are inexperienced in ESD.

Introduction

In recent years, there have been reports about the risk of infection with multidrug-resistant bacteria via duodenoscopes¹, as well as the outbreak of COVID-19, which has brought attention to endoscope-mediated infections. In response, disposable endoscopes have been developed and marketed worldwide. While there have been several reports on the feasibility of disposable endoscopes for screening or emergency examinations^2,3, there are no reports on the feasibility of Endoscopic Submucosal Dissection (ESD), which requires a variety of operations with different devices.

Aims & Methods

The aim of this study was to compare the performance of disposable and reusable endoscopes in using the ESD training model (G-master, KOTOBUKI Medical), which can simulate various parts of the stomach.
ESD was performed on pseudo lesions (size: 25 mm) at the 6 simulated locations on the ESD training model using the disposable endoscope (Ambu aScope Gastro, Ambu) and the reusable endoscope (GIF-Q260J, Olympus). A total of 24 lesions were treated by 3 ESD beginners (less than 30 ESD experience) and 3 ESD experts (over 300 ESD experience), each performing on 2 locations (4 lesions).
We evaluated procedure time, dissection speed, en bloc resection rate, perforation rate, scope malfunction rate, and number of scope removals during procedure. Additionally, we administered questionnaires to assess the endoscopists' opinions on each scope, including image visibility, manipulate handle operability, tip lens washing function, the ability of device insertion and removal, and scope operability at each site, rated on a scale of 0-5. The evaluations were classified as low (<2), moderate (2<= and <4), and high (4<=).

Results

All procedures were completed using the assigned scopes. The median procedure time was 24.2 min (range, 14.2-36.5) for the disposable endoscopes (Dispo), slightly longer than 19.6 min (range, 13.5-29.5) for the reusable endoscopes (Reuse). The median dissection speed was 20.3 mm²/min (range, 13.5-34.6) for Dispo and 25.2 mm²/min (range, 16.7-36.3) for Reuse, and the differences were not significant in both (procedure time: p-value=0.284, dissection speed: p=0.379). In the subgroup analysis, Dispo tended to have slightly longer procedure time than Reuse in beginner group (Dispo: 29.5 min [range, 20.0-36.5], Reuse: 25.2 min[range, 16.3-29.5], p=0.206). On the other hands, in expert group there was almost no difference in treatment time (Dispo: 16.4 min [range, 14.2-25.2], Reuse: 16.6 min [range, 13.5-21.1], p=0.453). The en bloc resection rate was 100%, not only for Reuse but also for Dispo. No cases of perforation or scope malfunction were observed in any of the scopes. For either scope, there were no lesions that required removal of the scope due to wiping the adhesion at the tip lens or any other reasons.
The results of the questionnaires were as follows image visibility: Dispo 2.3±0.9, Reuse 4.0±0.6; manipulate handle operability: Dispo 3.5±0.8, Reuse 4.5±0.5; tip lens washing function: Dispo 3.2±1.1, Reuse 3.8±0.9; the ability of device insertion and removal: Dispo 3.3±0.5, Reuse 3.7±0.5; scope operability (evaluated at each site): Dispo 3.3±0.8, Reuse 3.9±0.5. The scores of all items for Dispo were slightly lower than those for Reuse, particularly in terms of screen visibility and usability, but scored moderately well in all categories.

Conclusion

In the training model, the performance of the disposable endoscope in the ESD procedure was acceptable compared to the reusable endoscope. As a next step, we are planning to conduct clinical research.

References

1. U.S. Food and Drug Administration. Infections Associated with Reprocessed Duodenoscopes
2. Han.ZL, et al. Evaluation of a novel disposable esophagogastroduodenoscopy system in emergency, bedside, and intraoperative settings. DEN. 11 March 2023: Online ahead of print.
3. Luo.X, et al. Disposable versus reusable gastroscopes: a prospective randomized noninferiority trial. Gastrointest Endosc. 2022 Aug;96(2):250-261.

Disclosure

This research was conducted with a research fund and disposable scopes from Ambu, and with items related to ESD training model from KOTOBUKI Medical.

Introduction

There is a paucity of information on the efficacy and safety of endoscopic resection (ER) of gastric submucosal tumors (SMT) in Japan where ER for early gastric cancer is extremely popular.

Aims & Methods

A multicenter retrospective study was conducted to elucidate the current situation of ER for gastric SMT in Japanese endoscopic practice. Clinicopathological data of consecutive patients with gastric SMT who underwent ER in 12 Japanese hospitals were collected from the first case until August 2020.

Results

A total of 117 patients with 118 lesions were enrolled. The number of patients with gastric SMT who underwent ER increased over the years. The mean (SD) endoscopic tumor size was 20 (7.2) mm. The growth type was primarily intraluminal (90%). 87 (74%) of the procedures were performed in an operating room under general anesthesia. The tunneling method was used in 5 (4%) cases. The mean (SD) resection and wound closure times were 58 (38) min and 31 (41) min, respectively. Complete ER was achieved for 117 (99%) lesions. Full-thickness resection rate was 44%; however, only 12 (10%) patients required abdominal paracentesis for pneumoperitoneum. Endoscopic treatments were completed in 115 (97%) lesions, while three lesions required conversions to laparoscopic surgery due to luminal collapse, uncontrolled bleeding, and difficulty in defect closure. Two cases of delayed bleeding were managed by endoscopic hemostasis, one of which required a blood transfusion. Gastrointestinal stromal tumors were the most common pathology (74%). The R0 resection rate was 76%. Survival and recurrence on August 31, 2021, were confirmed in 112 patients (96%) with a mean (SD) follow-up period of 4.3 (2.9) years. 109 (94%) were confirmed alive, the vital status of five patients was unknown, and three patients had died of other diseases. No recurrence was observed. The 5-year overall survival rate was 98.9% (95% confidence interval, 97.8−100%).

Conclusion

The performance of ER for gastric SMT is increasing in Japan. The technique seems feasible in Japanese endoscopic practice, warranting further validation in a prospective study.

Introduction

Endoscopic submucosal dissection (ESD) is widely implemented in Asia. Experience from the western world is still limited, so the evidence on the description of a learning curve (LC) is sparse.

Aims & Methods

The aim of this study is to evaluate the LC for ESD of gastric lesions using accepted proficiency benchmarks (PB).
Retrospective analysis with a prospectively maintained database of all patients undergoing ESD at a Western tertiary center from June 2016 to December 2022.
Inclusion criteria: ESD of gastric lesions performed by a single operator.
Primary endpoint: a LC to estimate the number of ESDs required to achieve PB (>90% for en bloc resection, >80% for histologic margin-negative (R0) resection and resection speeds (RS) >9cm2/hr), using the CUSUM method.

Results

Of 477 ESD performed, a total of 235 ESD met the inclusion criteria.
The en bloc resection rate was 100%. The R0 resection rate was 97% so no statistically significant differences were found, since it was always within PB.
Using the CUSUM method, the LC was divided into learning periods [Phase I - learning phase (cases 1-48); Phase II - adaptation phase (49-72), Phase III - consolidation (from case 73 on).
Globally, after reaching the level of 9cm2/h and after resection 73, the cumulative moving average remains above this speed for all following resections.
Several locations reach moving average proficiency levels at different number of interventions (antrum: from the beginning, body: 134th).

Conclusion

The PB regarding the en bloc and R0 resection were achieved from the beginning.
The PB regarding de RS was achieved from the beginning for the antrum.
The PB regarding de RS, globally, has a clinically significant first learning inflection at ESD number 49 and at ESD number 73 achieved sustained PB for RS.

Disclosure

There are no conflict of interest.

Introduction

In superficial gastric tumors, endoscopic submucosal dissection (ESD) has become the standard of care, and the treatmenttechnique and strategy have been matured. On the other hand, the number of cases performed by trainees as anintroduction to ESD is increasing, and the types and handling of antithrombotic drugs are also changing.

Aims & Methods

On these backgrounds, we examined the transitions to clarify how the treatment outcomes and adverse events of gastric ESD have changed.
From 2014 to 2022, 565 patients of superficial gastric neoplasms who underwent ESD were divided into two groups: the first half (n=435) from 2014 to 2020 and the second half (n=130) from 2021 to 2022, where the number of trainees significantly increased. Treatment outcomes (En bloc resection rate, curability, procedure time, inflammatory response)and adverse events (perforation, postoperative bleeding, postoperative pneumonia, and pyrexia for unknown reasons) were retrospectively compared between two groups, using the propensity score matching analysis. Regarding oral antithrombotic agents, antithrombotic drugs were continued, DOAC stopped only 24 hours before treatment, and warfarin was continued after INR value was controlled at <3.0.

Results

Propensity score matching yielded 130 pairs. Trainee's involvement was 29.7% in the first half and 61.4% in the second half. The comparison demonstrated a significant difference for the following outcomes: curability was 86% in the first half and 90.1% in the second half (P=0.028), the CRP mean [SD] was 1.32 [2.14] in the first half and 0.82 [0.97] in the second half (P=0.032), and postoperative bleeding rate was 5.9% in the first half and 0.0% in the second half (P=0.013). Others were similar values for outcomes.

Conclusion

Even with the increased involvement of trainees, treatment outcomes have not chronologically exacerbated. Additionally, inflammatory response and postoperative bleeding have improved. These results suggest that safe and secure gastric ESD can be performed by appropriate technique and strategy under supervise of experts.