Introduction

​Endocytoscopy (ECS), an ultrahigh-magnification contact-type endoscopy, enables real-time visualization of gastrointestinal mucosal and neoplastic cells. As a result, ECS enhance diagnostic precision as a form of optical biopsy. However, the reliability of ECS diagnosis is contingent upon adequate staining, which remains a considerable challenge in the stomach due to the abundance of mucus and inflammatory exudates that hinder optimal visualization. Weak vital staining can easily reduce the reliability of ECS diagnosis. Texture and Color Enhancement Imaging (TXI), a digital image enhancement modality developed by Olympus, enhances three key imaging elements—brightness, texture, and color tone—to optimize lesion visualization even under suboptimal staining conditions. Consequently, TXI may augment the diagnostic utility of ECS.

Aims & Methods

The aim of this study was to evaluate whether TXI enhances the diagnostic performance of ECS in early gastric cancer. Twenty-eight patients with 30 gastric cancers scheduled for magnifying endoscopic examination at Nippon Medical School Tama Nagayama Hospital between February 2024 and March 2025 were prospectively enrolled. All ECS procedures were performed with GIF-H290EC (Olympus Co., Tokyo, Japan) and the video processors EVIS X1 (Olympus Co., Tokyo, Japan). For in vivo dyeing, double staining with crystal violet and methylene blue was used. ECS was performed with and without TXI in both cancer and non-cancerous legions. ECS observation is performed by first taking photographs without TXI, and then taking photographs of the same area using the TXI. From each lesion, five ECS images with and without TXI were selected, resulting in a blinded and randomized image catalog (comprising 300 images from 30 gastric cancers and 280 images from 28 non-tumor areas). Two endoscopists independently assessed the images using a numerical rating scale (NRS, 0–10) to evaluate the visibility of nuclear atypia and structural cellular atypia. Diagnostic accuracy was assessed against pathological diagnosis as the gold standard. ECS diagnoses were rendered based on previously established criteria, wherein lesions exhibiting high-grade atypia were classified as cancer (Kaise M, et al. Endoscopy. 2015).

Results

The overall accuracy, sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) for EGC diagnosis by the two endoscopists were 82.5%, 84.3%, 80.7%, 81.3%, and 83.8%, respectively. The rate of interobserver agreement between the two endoscopists was high, with a kappa coefficient of κ = 0.797. Notably, diagnostic accuracy was significantly higher in the TXI images compared to the non-TXI images (85.2% vs. 79.0%, p = 0.0027). While the NRS scores for structural atypia did not differ significantly between the TXI and non-TXI images (4.90 vs. 4.87, p = 0.61), the NRS scores for nuclear atypia were significantly elevated in the TXI images (6.88 vs. 5.88, p < 0.0001).

Conclusion

​The integration of TXI with ECS significantly enhances the visualization of nuclear atypia and improves diagnostic accuracy in the diagnosis of gastric cancer. This synergistic approach facilitates superior optical biopsy capabilities, enhancing its clinical utility in the endoscopic diagnosis of early gastric cancer.

References

Kaise M, Ohkura Y, Iizuka T, Kimura R, Nomura K, Kuribayashi Y, et al. Endocytoscopy is a promising modality with high diagnostic accuracy for gastric cancer. Endoscopy. 2015;47:19–25.

Introduction

Endoscopic resection techniques, such as Endoscopic Mucosal Resection (EMR) and Endoscopic Submucosal Dissection (ESD), are used to remove precancerous and early-stage cancerous lesions in the gastrointestinal tract. While ESD is the gold standard due to its en-bloc and R0 resection capability, Underwater Endoscopic Mucosal Resection (UEMR) has emerged as an alternative. UEMR uses water buoyancy to aid lesion resection, potentially improving safety and reducing procedure time. However, its comparative effectiveness remains unclear.

Aims & Methods

The primary aim of this systematic review and meta-analysis is to compare the efficacy, safety, and procedural efficiency of Underwater Endoscopic Mucosal Resection (UEMR) versus Endoscopic Submucosal Dissection (ESD) in the treatment of gastrointestinal lesions.
A systematic search was conducted in PubMed, Embase, Google Scholar, Scopus, and Cochrane Library. Eligible studies compared UEMR and ESD in gastrointestinal lesions, providing data on en-bloc resection, R0 resections, adverse events, and procedure time. Randomized controlled trials (RCTs), cohort studies, and comparative studies were included.
Two reviewers independently extracted data, resolving discrepancies by discussion. Study quality was assessed using the Cochrane Risk of Bias Tool. Random-effects models were used for pooled analyses, calculating odds ratios (OR) and mean differences with 95% confidence intervals (CI). Heterogeneity was evaluated via the I² statistic.

Results

The analysis included four studies (three RCTs and one cohort study), with a total of 651 patients. Regarding efficacy, UEMR showed significantly lower en-bloc resection rates compared to ESD (OR = 0.01, 95% CI [0.01–0.06], Z = 6.85, p < 0.00001), suggesting a reduced ability to achieve complete lesion removal in a single piece. Similarly, R0 resection rates were also lower in the UEMR group (OR = 0.16, 95% CI [0.09–0.22], Z = 9.09, p < 0.0001), although with high heterogeneity (I² = 83%), possibly reflecting variations in patient selection, operator expertise, and technical differences among studies. In terms of safety, no significant difference was observed in adverse event rates between UEMR and ESD (OR = 0.48, 95% CI [0.10–2.34], Z = 0.90, p = 0.37), indicating comparable safety profiles. However, UEMR demonstrated an advantage in procedural time, being 5.89 times faster than ESD (p < 0.0001). This suggests that while UEMR may offer time efficiency, it comes at the cost of lower en-bloc and R0 resection rates, raising questions about its suitability for lesions requiring complete and margin-free excision. Further studies are needed to clarify the impact of these differences on long-term patient outcomes and to determine the optimal indications for UEMR in clinical practice.

Adverse Events
Total	-	248	-	401	100%	0.14 [0.09, 0.22]
Study	UEMR Adverse Events	UEMR Total Pacients	ESD Adverse Events	ESD Total Pacients	Weight	Odds Ratio M-H, Fixed, 95% CI
Inoue et. al	45	125	263	306	87,6%	0.09 [0.06,0.15]
Kim et al.	71	76	5	5	0,7%	1.18 [0.06, 24.27]
Okimoto K.	4	11	11	11	6,4%	0.03 [0.00, 0.56]
Park et al.	31	36	68	79	5,3%	1.00 [0.32, 3.13]

Conclusion

UEMR offers a quicker alternative to ESD but lacks its high resection quality, making ESD preferable for lesions requiring en-bloc or R0 resection. Gastroenterologists must weigh UEMR’s speed against ESD’s superior efficacy. Standardizing UEMR techniques may improve its resection quality and expand its role in clinical practice. Future research should optimize UEMR and address variability in resection outcomes.

References

1. Nett A, Binmoeller K. Underwater Endoscopic Mucosal Resection. Gastrointest Endosc Clin N Am. 2019 Oct;29(4):659-673. doi: 10.1016/j.giec.2019.05.004.
2. Ferlitsch M et al. Colorectal polypectomy and endoscopic mucosal resection: European Society of Gastrointestinal Endoscopy (ESGE) Guideline - Update 2024. Endoscopy. 2024;56(1):1-20. doi: 10.1055/a-2304-3219.
3. de Souza MHG, Ribeiro IB, de Moura DTH, et al. Underwater versus conventional endoscopic mucosal resection for colorectal lesions: a systematic review and meta-analysis of randomized clinical trials. Surg Endosc. 2023;37(5):3456-3465. doi: 10.1007/s00464-022-09456-7
4. Chandan S, Mohan BP, Khan SR, et al. Safety and efficacy of underwater versus conventional endoscopic mucosal resection for colorectal polyps: Systematic review and meta-analysis of RCTs. Gastrointest Endosc. 2023;97(6):1087-1095.e3. doi: 10.1016/j.gie.2023.01.012.
5. Inoue T, Nishida T, Maekawa A, et al. Underwater endoscopic mucosal resection versus endoscopic submucosal dissection for 20–30 mm colorectal polyps: a prospective randomized study. Endoscopy. 2022;54(5):456-464. doi: 10.1055/a-1500-1234.
6. Park SS, Lee IS, Lee SH, et al. Comparison of underwater endoscopic mucosal resection and endoscopic submucosal dissection of rectal neuroendocrine tumors (with videos). Gastrointest Endosc. 2021;93(3):637-646.e2. doi: 10.1016/j.gie.2020.08.030.
7. Takeuchi Y, Uedo N, Hotta K, et al. Underwater endoscopic mucosal resection for colorectal lesions: Can it be an “Underwater” revolution? World J Gastroenterol. 2020;26(20):2545-2553. doi: 10.3748/wjg.v26.i20.2545.

Introduction

There is increasing recognition that effective resident training in gastrointestinal endoscopy should be provided by endoscopists who have received formal educational training in the teaching of endoscopy.¹ While the implementation of Training the Colonoscopy Trainers (TCT) courses has led to significant improvements in colonoscopy quality outcomes^2,3 and polyp detection rates,⁴ evidence regarding the impact of TCT participation on teaching performance and resident learning – both of which are main goals of faculty development initiatives – is still lacking. Therefore, the aim of the present study was to evaluate the effectiveness of TCT course implementation using Kirkpatrick’s model of training evaluation.

Aims & Methods

In this study, 24 gastroenterologists from a university hospital and two affiliated general teaching hospitals in the north-eastern educational region of the Netherlands, participated in a two-day TCT course. The course was evaluated at three levels of Kirkpatrick’s model: (a) post-course evaluations reflecting the initial reaction; (b) video analysis of endoscopy training in the workplace before and after the TCT course using the mini-Structured Training Trainer Assessment Report (mini-STTAR); (c) a post-course resident survey reflecting the impact on the home-environment. Descriptive statistics and non-parametric tests were used to analyse the effectiveness of the TCT course.

Results

The TCT course was well received by participants, they highlighted the use of a structured training framework as a strength. Video analysis of endoscopy training in the workplace demonstrated a significant improvement in post-course trainer performance, both at 1-3 months (T1) and 6-9 months (T2). Significant improvements were found in the overall mini-STTAR scores (p<0.001), and across most mini-STTAR items, particularly in the items related to the phase preceding the actual training (referred to as the Set) and the evaluation after completion of the training (referred to as the Closure). Regarding the actual training (referred to as the Dialogue), participants demonstrated a significant positive change in ‘guiding/deconstructing’ and ‘controlling’ (both at T1 and T2) and in ‘encouraging/praise’ (only at T2). Participants received significantly higher 5-point Likert scale ratings as ‘excellent trainer’ at T1 (mean 4.13) and T2 (mean 4.29), compared to baseline (mean 3.58, p<0.001). In the post-course survey, all residents (N=16) were satisfied with the supervision of endoscopy trainers in their teaching hospitals. Nine (56%) reported uniform endoscopy supervision among trainers, a significant increase compared to a pre-course resident survey (8%, p=0.034).⁵ Although residents reported that the frequency of a didactic Set and Closure did not increase, most respondents indicated that the implementation of the TCT course improved the setting of learning objectives, the provision of spontaneous feedback, guidance during difficult endoscopies, and the prevention of undesired scope takeover.

Conclusion

The implementation of a TCT course provided a structured and useful training framework, and enhanced trainer performance, particularly in the didactic pre- and post-endoscopy training discussions, as well as in guiding, controlling, encouraging, and providing spontaneous feedback during the training of residents in gastrointestinal endoscopy.

References

1. Antonelli G, Voiosu AM, Pawlak KM, et al. Training in basic gastrointestinal endoscopic procedures: a European Society of Gastrointestinal Endoscopy (ESGE) and European Society of Gastroenterology and Endoscopy Nurses and Associates (ESGENA) Position Statement. Endoscopy. 2024;56:131-150
2. Waschke KA, Anderson J, Macintosh D et al. Training the gastrointestinal endoscopy trainer. Best Pract Res Clin Gastroenterol. 2016;30:409-419
3. Gavin DR, Valori RM, Anderson JT, et al. The national colonoscopy audit: a nationwide assessment of the quality and safety of colonoscopy in the UK. Gut. 2013;62:242-249
4. Hoff G, Botteri E, Huppertz-Hauss G, et al. The effect of train-the-colonoscopy-trainer course on colonoscopy quality indicators. Endoscopy. 2021;53:1229-1234
5. Mousset RA, de Vos Tot Nederveen Cappel WH, Pierie JEN et al. Endoscopy training in the Netherlands: a national survey among gastroenterology residents. Endosc Int Open. 2022;10:E1548-E1554

Introduction

Endoscopic ultrasound (EUS) has been established as a fundamental diagnostic and therapeutic tool in the management of gastrointestinal and biliopancreatic diseases. However, its long learning curve, particularly for therapeutic procedures, adds a level of complexity to EUS learning. A dedicated therapeutic EUS simulator may help physicians acquire and refine technical skills before exposition to real-life cases.

Aims & Methods

We aim to assess the feasibility and preliminary feedback of an EUS simulator box for therapeutic EUS training. The EUS simulator box was used for 150 minutes on the first training day of a 3-day hands-on therapeutic EUS course held on the International Therapeutic Endoscopic Ultrasound Course (ITEC) at IHU Strasbourg. It includes a porcine visceral block placed inside a specially designed box, including esophagus, stomach, duodenum, pancreas, lymph nodes, liver, gallbladder, spleen and kidneys. It allows endoscopic and ultrasound visualization mimicking human anatomy and replicates pathological conditions such as ascites and intra-abdominal collections. Trainees performed various procedures on the simulator including fine needle aspiration (FNA), fine needle biopsy (FNB), lumen-apposing metal stents (LAMS) and plastic stents cysto-gastrostomies. After completing all the procedures, participants were asked to fill in an evaluation form, which included five questions assessing simulation realism and procedural practice, scored on a quality scale from 0 (not good) to 5 (excellent).

Results

Twelve participants with varying levels of EUS training (mean 6.5 years of hands-on experience) were included. A total of 25 procedures were completed on two EUS simulator boxes (FNB=9, FNA=2, Cystogastrostomy using plastic prothesis=4, Cystogastrostomy using LAMS= 10). Most participants (10/12, 91,6%) rated the realism of the simulation as high, giving scores of 4 or 5. Additionally, 75% (9/12) rated the practice quality for specific procedures as excellent. All participants agreed that the EUS simulator box should be included in the standard EUS training curriculum.

Conclusion

The EUS simulator box has a realistic anatomical correlation and ease of use, shows potential as an effective simulator for both basic and advanced therapeutic EUS procedures, reducing the use of live animals for medical training. Further studies with larger sample size are needed to validate its educational value and impact on clinical practice.

Introduction

Endoscopic submucosal dissection (ESD) demands a high level of endoscopic skill and extensive training, even for experienced endoscopists, with a particularly steep learning curve for colonic ESD. Over the last three years, the French Society of Digestive Endoscopy (SFED) has implemented a structured ESD training program. This study aimed to evaluate the effectiveness of the SFED ESD training program to achieve competency in ESD and to identify factors associated with it.

Aims & Methods

Participants who attended the SFED ESD training curriculum over the past three years were invited to join the study. After completing a standardized initial simulation training week, each participant was asked to document each ESD procedures performed in their training center, along with technical details for each (lesion size and location, en bloc resection, R0 resection status, and procedural complications). Additionally, participants completed an online survey to gather information about their practice environment, ongoing ESD activity, and demographic data (e.g., gender, age, prior endoscopy experience). Successful dissection was defined as en-bloc resection with free lateral and deep margins (R0) and no need for surgical intervention due to complications. The performance threshold for achieving proficiency in ESD was defined, in line with ESGE guidelines, as achieving an en-bloc resection rate of >90% and a complication-related surgery rate of <1%. The learning curve to reach these competence standards was assessed using the LC-CUSUM method.

Results

A total of 45 students participated in the study. The majority were men (70%), with a median age of 36 years. They practice endoscopy for 6 years (IQR 4-10) and 82% performed interventional endoscopy (ERCP and EUS).
A total of 2,068 ESD procedures were performed by the trainees. The median number of ESDs conducted post-training was 34 (IQR 22-66), with the majority being colorectal (42.9% rectal and 42.7% colonic). Lesions had a median size of 45 mm (IQR 34-60), with a resection speed of 17.4 mm²/min (IQR 10.5-26.5). En bloc resection and R0 resection were achieved in 93.6% and 85.8% of cases, respectively, with a surgical complication rate of 0.94%. The overall success rate of ESD procedures was 92.7%. Success was more likely in rectal (97%) than colonic (90.4%) procedures. 75% of the students were competent. Among those who reached competence, the median number of ESDs required was 45. Factors associated with competency were : ESD localization (rectum > colon), the age (HR 0.92 [0.86-0.99]; p = 0.03) and experience (HR 0.91 [0.84-0.99]; p = 0.03) were inversely correlated to the competency. Practiced in a high volume ESD center (>100 ESD/year) lead to reach competency faster (p =0.008).

Conclusion

This study provides the first assessment of the SFED ESD training program in France. Competence in ESD is reachable after appropriate training. A big experience is not needed to attempt ESD. Supervised training is essential, and seems easier in a high-volume center to achieve competence more quickly. These findings may help inform the selection of future candidates for ESD training to ensure effective skill acquisition and safe practice.

Disclosure

nothing to disclose

Introduction

Endoscopic submucosal dissection (ESD) was developed in Japan decades ago and is now widely used as a minimally invasive treatment in Western countries. On-the-job training is the major method for acquiring ESD skills; thus, learning ESD is difficult for foreign endoscopists, who have less opportunity to perform it in their country. ENDONIX (Olympus, Tokyo, Japan) is a laptop-based next-generation 3D printed endoscopy simulator that allows basic and advanced endoscopy training. This study aims to evaluate the effectiveness of ENDONIX training for improving novice foreign endoscopists’ ESD skills.

Aims & Methods

This prospective, single-center, exploratory study was conducted at National Cancer Center Hospital (NCCH) between January 2024 and January 2025. Foreign endoscopists who had performed fewer than three ESD cases and participated in an international training program at NCCH were included. Participants were assigned 1:1 to either the Group A (Day 1-14: ENDONIX training with ESD observation followed by Day 15-28: ESD observation alone) or Group B (Day 1-14: ESD observation alone followed by Day 15-28: ENDONIX training with ESD observation). During the training period, participants performed three basic and one advanced training program on ENDONIX every day. On Days 1, 15, and 29, the endoscopists performed ESD for a 2cm lesion at the lesser curvature of the middle gastric body using a non-animal ESD model (G-Master, KOTOBUKI MEDICAL, Tokyo, Japan), and their technical performance was assessed at each time point. All procedures were supervised by a single experienced endoscopist (TU). The primary endpoint was the improvement in dissection speed (mm/min²) from Day 1 to Day 15 between the groups. Paired t-test was used to compare the corresponding continuous variables.

Results

		Group A	Group B	P value
Day 1	mean (SD) [95% CI], mm2/min	12.2 (2.8) [6.8 – 17.7]	13.4 (2.2) [9.1 – 17.7]	0.75
Day 15	mean (SD) [95% CI], mm2/min	18.6 (2.8) [13.2 – 24.1]	12.6 (1.4) [9.9 – 15.4]	0.10
Day 29	mean (SD) [95% CI], mm2/min	27.4 (2.8) [22.0 – 32.8]	18.4 (1.6) [15.2 – 21.5]	< 0.05

A total of 10 foreign endoscopists were enrolled in this study. The median age was 34 in Group A and 28 years in Group B. Nationalities in Group A were Spanish (n=3), Portuguese (n=1), and Chinese (n=1); in Group B, Spanish (n=4) and Ukrainian (n=1). All Group A endoscopists specialized in gastroenterology; Group B included four gastroenterologists and one oncologist. No significant differences were found between groups in baseline endoscopic experience. All participants completed predetermined ENDONIX training during the study period. ESD was performed on all designated days using G-Master, and en-bloc resection was achieved for the target lesions on without intraoperative perforation or damaging the resected specimen. The mean dissection speed significantly increased from Day 1 to Day 15 in Group A (“ENDONIX training with ESD observation”) (12.2 vs 18.6, p < 0.05). No significant differences were observed from Day 1 to Day 15 in Group B (“ESD observation alone”) (13.4 vs. 12.6, p = 0.81), while the mean dissection speed significantly increased from Day 15 to Day 29 (12.6 vs. 18.4, p < 0.05). Although the difference on Day 15 was not statistically significant between the groups (18.6 vs. 12.6, p = 0.10), Group A demonstrated a significantly higher dissection speed than Group B on Day 29 (27.4 vs. 18.4 p < 0.05), (Table 1).

Conclusion

The systematic endoscopy training with the ENDONIX platform improved the novice foreign endoscopists’ ESD skills. Dissection speed increased in the period receiving systematic ENDONIX training, highlighting the importance of systematic endoscopy training.

Disclosure

None

Introduction

Training with silicone models in colonoscopy is limited by the lack of realistic texture and appearance of mucosal tissue. Artificial intelligence (AI) offers a novel solution by enabling simulation of realistic appearing mucosa, which can enhance the overall visual realism of silicone-based models for endoscopic training.

Aims & Methods

We developed, using 239,875 images from 3,452 colonoscopies recorded using five different endoscopic processors, a style transfer AI model capable of transforming endoscopic video footage from a silicone colon into a video that visually mimics real mucosal tissue. The model was applied to two representative clips recorded from a silicone colon model, covering lesions and normal mucosa. Both the original and AI-enhanced videos were shown to N = 12 gastroenterologists (board certified and in training), who provided quantitative evaluations using a 5-point Likert scale (1: Strongly disagree, 5: Strongly agree) and free-text qualitative feedback. We conducted the statistical analysis using Wilcoxon signed-rank tests with Pratt adjustment for zero differences and analyzed the qualitative feedback with an inductive content analysis after Mayring.

Results

All physicians prefer the AI-enhanced videos over the original silicone footage due to the more realistic representation of the colon. This can also be seen from the quantitative data, as the participants rated the AI-enhanced videos as significantly more visually realistic (M = 2.42 vs 4.17, Z = -3.22, p < .001), helpful for training (M = 3.67 vs 4.25, Z = -2.65, p = .016) and polyp characterization (M = 2.92 vs 3.75, Z = -2.38, p = .027), favored for usage (M = 2.92 vs 4.00, Z = -2.80, p = .005), and facilitating optical diagnoses (M = 3.58 vs 4.42, Z = -2.23, p = .039). Though, the participants rated the original silicone footage as significantly less mentally demanding than the AI-enhanced videos (M = 1.67 vs 2.42, Z = -2.61, p = .016). Open-ended feedback highlighted the more realistic AI generated mucosa as an enhancement (100 %) to the unrealistic silicone surface (92 %) while suggesting that further development should focus on integrating more realistic lesions (33 %) and increasing mucosal details (42 %).

Conclusion

AI-driven simulation of normal mucosa improves the realism, acceptance, and educational value of silicone colon models used in endoscopy training.