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.

Introduction

Prophylactic wound closure after Endoscopic Submucosal Dissection (ESD) is suggested in high-risk patients to reduce delayed AEs (e.g. bleeding). The closure of large wounds can be challenging with standard endoscopic devices (e.g. endoclips) and dedicated devices are needed. Endoscopic Hand-Suturing (EHS) can be a therapeutic option to close extensive gastrointestinal defects. The current study presents the EHS experience from two Italian centers, aiming to assess the feasibility and clinical effectiveness of the EHS technique.

Aims & Methods

Data from two high-volume endoscopic Italian centers were retrospectively collected. Patients with an ESD wound closed using the SutuArt (Olympus Medical Systems, Tokyo, Japan) device were enrolled in the study (Figure1). Demographics, technical data, success rate, suturing speed, and AEs were recorded

Results

Between June 2023 and August 2024 10 patients were enrolled in the study, demographics in Table 1. All patients were at high-risk for delayed bleeding after gastric or colorectal ESD (figure2). The mean lesion size was 34mm (range 15-45). In all cases SutuArt (Olympus Medical Systems, Tokyo, Japan) needle holder with V-LOC 180, size 3-0 threads (Medtronic) were used. All procedures were performed by two expert endoscopists. ESD-wound closure was successfully achieved in 90% of cases. The mean suturing time was 42 min (range: 25–65 min, SD=23.3 min) meanwhile the mean ESD time was 86 minutes (range: 15–185min, SD=38min). Suturing significantly increased the total procedure time (120min Vs 86min, p<0.001). In one case, the wound closure failed due to suture breakage, resulting in needle entrapment within the mesorectum, with the impossibility of retrieving it. No other AEs were reported.

Conclusion

ESD-defects closure with EHS is feasible and safe with promising outcomes. However, this technique is significantly time-consuming. Probably extended training may be required for endoscopists performing suturing, and further studies are needed to assess the real-life applicability and the cost-effectiveness of this technique.

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

Hot endoscopic mucosal resection (H-EMR) is the standard of care for large non-pedunculated colorectal polyps (LNPCPs) without suspicion of submucosal invasion, achieving low recurrence rates after en bloc resection or piecemeal resection with margin ablation in expert centers.^1,2 However, electrocautery is also responsible for complications which can lead to significant morbidity and necessitate additional invasive procedures.^3,4 Cold snare polypectomy (CSP) has proven to be preferable to H-EMR for adenomas ≤10mm and non-dysplastic sessile serrated lesions, providing comparable efficacy with improved safety, shorter procedural time and lower costs.⁵ These advantages have driven interest in expanding CSP to larger polyps.

Aims & Methods

This meta-analysis of randomized controlled trials (RCTs) aimed to compare the risk of recurrence and adverse events between cold snare polypectomy (CSP) and hot-endoscopic mucosal resection (H-EMR) for large non-pedunculated colorectal polyps (LNPCPs).
A systematic search of Medline, Embase and Cochrane Library databases was performed through August 2024 for studies comparing recurrence, bleeding and perforation rates between CSP and H-EMR for LNPCPs ≥15mm (PROSPERO ID: CRD42024568272). RCTs were included in the quantitative analysis. A random-effects meta-analysis, with heterogeneity measured with I², was conducted to generate pooled risk ratios (RR) with 95% confidence intervals.

Results

Four RCTs comprising 1516 LNPCPs (766 CSP and 750 H-EMR) in 1442 patients were included in the quantitative analysis. CSP demonstrated a higher recurrence risk at first surveillance colonoscopy than H-EMR in the pooled analysis (22.6% vs. 10.8%; RR=1.98; 95% CI: 1.22–3.21; p=0.02; moderate-certainty evidence), corresponding to a number needed to harm of 9. Regarding adverse events, CSP demonstrated a 67% reduced risk of delayed bleeding (1.2% vs. 3.9%; RR=0.33; 95% CI: 0.12-0.89; p=0.03; high-certainty evidence), corresponding to a number needed to treat of 37. Although CSP appeared to reduce the risk of intraprocedural bleeding (10.0% vs. 19.8%; RR=0.30, 95% CI: 0-52256.34, p=0.42), the wide confidence interval from the random-effects model included 1. There were no intraprocedural or delayed perforations in the CSP group.

Author	Study design	Number of patients		Age, mean (SD), years	Female, %	Number of LNPCPs		LNPCP size, mean/median (SD/IQR), mm	Right Location, %		Adenomatous histology, %
		CSP	H-EMR			CSP	H-EMR		CSP	H-EMR	CSP	H-EMR
O’ Sullivan T. et al., 2024	Single center, RCT	87	90	68.2 (10.0)	46.9	87	90	30 (25-35)	96.5	86.7	100	100
Steinbrück et al., 2024	Multicenter, RCT	184	192	65.9 (10.5)	48.2	193	203	30.1 (10.2)	88.1	86.2	60.7	68.5
Pohl H. et al., 2024	Multicenter, RCT	336	324	65.3 (10.2)	47.7	371	343	30 (25.4)	82.5	83.4	NR	NR
Nogales et al., 2023	Multicenter, RCT	115	114	67.9 (10.6)	43.3	115	114	25 (22-30)	80.0	78.1	71.9	77.2

Table 1. Patients, LNPCPs and procedure characteristics of the randomized controlled trials included in the quantitative analysis. (List of abbreviations: CSP, cold snare polypectomy; H-EMR, hot endoscopic mucosal resection; IQR, interquartile range; LNPCPs, large non-pedunculated colorectal polyps; NR, not reported; SD, standard deviation; RCT, randomized controlled trial)

Conclusion

CSP has nearly double the recurrence risk of H-EMR for LNPCPs. However, its superior safety profile may make it a preferable option for patients where procedural safety is prioritized over radicality, such as those with extensive comorbidities.

References

1. Ferlitsch M, Hassan C, Bisschops R et al. Colorectal polypectomy and endoscopic mucosal resection: European Society of Gastrointestinal Endoscopy (ESGE) Guideline - Update 2024. Endoscopy 2024; 56: 516-545. doi:10.1055/a-2304-3219
2. Kaltenbach T, Anderson JC, Burke CA et al. Endoscopic Removal of Colorectal Lesions: Recommendations by the US Multi-Society Task Force on Colorectal Cancer. Am J Gastroenterol 2020; 115: 435-464. doi:10.14309/ajg.0000000000000555
3. Sidhu M, Shahidi N, Gupta S et al. Outcomes of Thermal Ablation of the Mucosal Defect Margin After Endoscopic Mucosal Resection: A Prospective, International, Multicenter Trial of 1000 Large Nonpedunculated Colorectal Polyps. Gastroenterology 2021; 161: 163-170.e163. doi:10.1053/j.gastro.2021.03.044
4. Meulen LWT, Bogie RMM, Winkens B et al. Thermal ablation of mucosal defect margins to prevent local recurrence of large colorectal polyps: a systematic review and meta-analysis. Endosc Int Open 2022; 10: E1127-e1135. doi:10.1055/a-1869-2446
5. Rex DK, Anderson JC, Pohl H et al. Cold versus hot snare resection with or without submucosal injection of 6- to 15-mm colorectal polyps: a randomized controlled trial. Gastrointest Endosc 2022; 96: 330-338. doi:10.1016/j.gie.2022.03.006