Introduction

Optical diagnosis attempts to guide the endoscopist in making a treatment choice, however, selecting lesions with possible covert cancer (CONECCT IIA lesions: JNET IIA, no macronodule, no depressed area), high-risk lesions (CONECCT IIC lesions: JNET IIB or macronodule or depressed area) or overt submucosal invasive carcinoma (SMIC) (CONECCT III lesions: JNET III area) remains challenging.

Aims & Methods

We aim to describe the endoscopic and oncologic outcomes of endoscopically removed T1-colorectal cancers (T1-CRC), according to their pre-resection classification by optical diagnosis. This is a multicenter prospective cohort study in 13 centers. Procedural and oncological outcomes were analyzed using univariate analysis.

Results

7495 colorectal ESDs were included from 09/2019 to 09/2024, with a median lesion size of 50mm [35-65], rectal location in 35.3% and right colon in 37.9%. Lesions were classified as CONECCT IIA in 28.4%, CONECCT IIC in 60.3% and CONECCT III in 5.3%. En-bloc, R0 and curative resection rates were 96.3%, 88.1% and 81.4%, with significant decreasing trends as the CONECCT classification advanced (97.3%; 91.9%; 90.7% in CONECCT IIA, 96.3%; 87.6%; 80.6% in CONECCT IIC and 93.2%; 74.2%; 32.0% in CONECCT III, respectively; p<0.001). T1-CRC occurred in 10.4% and the prevalence significantly differed according to the optical diagnosis: 2.3% in CONECCT IIA, 10.8% in CONECCT IIC and 49.6% in CONECCT III. En-bloc, R0 and curative resection rates were 96.7%, 74.9% and 23.6% respectively, with a significant decreasing trend in curative resection rates as the CONECCT classification increased (25.5% CONECCT IIA, 26.5% CONECCT IIC and 13.9% CONECCT III; p=0.002). Vertical margins were free in 80.3%. Overall median depth of SMIC was 1500µm [750-2560], measuring 1426µm in CONECCT IIA, 1840µm in CONECCT IIC and 2744µm in CONECCT III (p<0.001), corresponding to deep SMIC in 46.8% in CONECCT IIA, 62.2% CONECCT IIC and 77.1% CONECCT III (p<0.001). Lympho-vascular invasion and tumor budding were more frequently observed in CONECCT III at 30.0% and 34.3% respectively (vs 23.9%; 23.9% in CONECCT IIA and 16.4%; 20.6% in CONECCT IIC; p=0.002). Poor differentiation was reported in 5.3% with no significant difference between categories. Finally a trend was noted in the number of prognostic risk factors per lesion: no high-risk factors in 34.0% of CONECCT IIA, 29.5% in CONECCT IIC and 18.6% in CONECCT III, versus 3 high-risk factors in 4.3% in CONECCT IIA, 7.0% in CONECCT IIC and 11.2% in CONECCT III (p=0.049).

Conclusion

Endoscopic resection of T1-CRC demonstrates high en-bloc and R0 resection rates. However, curative outcomes and oncologic features worsen significantly with the presence of risky optical diagnostic criteria, highlighting the importance of adequate optical diagnosis and considering intramuscular resection techniques for advanced lesions, balancing over- and undertreatment as nearly 50% of CONECCT III lesions were T1-CRC.

References

Brule C, Pioche M, Albouys J, et al. The COlorectal NEoplasia Endoscopic Classification to Choose the Treatment classification for identification of large laterally spreading lesions lacking submucosal carcinomas: A prospective study of 663 lesions. United European Gastroenterol J, 2022;10():80-92

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.

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

​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

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

Linked color imaging (LCI), a unique image-enhanced endoscopy technique, expands the color range to enhance the recognition of subtle mucosal differences, facilitating early lesion detection. Recently, the advantage of LCI in cancer visibility and detection has been reported especially in Helicobacter pylori (H. pylori)-negative gastric cancer including cases post-eradication.¹ However, the correlations between the color of LCI’s visualized mucosa and histological findings have not been thoroughly investigated.

Aims & Methods

This study aimed to investigate relationships between color values and histological findings visualized by LCI in H. pylori-negative gastric cancer.
Thirty-two patients with H. pylori-negative, differentiated-type intramucosal gastric cancer (≤20 mm) who underwent endoscopic submucosal dissection were retrospectively reviewed. Images captured with LCI and white light imaging (WLI) were analyzed using the CIE1976 (L^*a^*b^*) color space, as defined by the International Commission on Illumination (CIE).² Three regions of interest, each measuring 10 × 10 pixels, were set on the malignant tumor and adjacent mucosa to the border. The values of a^*(red-green) and b^* (yellow-blue) and the color difference (ΔE), which represents the overall difference between the two colors, were calculated. Histopathological evaluation using Hematoxylin-Eosin stained specimens was performed to highlight the demarcation between cancerous and noncancerous mucosa in a width of 1.0 mm inside and outside the lesion. Vascular density, glandular density, mucosal thickness, and the degrees of intestinal metaplasia (IM) were measured. Vascular density was calculated as the percentage of the occupied blood vessels in an area up to 200 μm from the surface. And the proportion of IM relative to the glands was measured and classified as the severe IM (≥60%), moderate IM (≥30% and <60%), or mild IM (<30%) groups.

Results

LCI significantly increased ΔE between the cancer and surrounding mucosa compared with WLI (P < 0.001); however, no significant differences in Δa^* and Δb^* were observed between LCI and WLI. Moderate correlations were observed between LCI a^* values and vascular density (ρ = 0.39, P < 0.001) and between LCI b^* values and the proportion of IM (ρ = −0.49, P < 0.001). Furthermore, the vascular density of cancer in the 0−100 μm depth showed a moderate correlation with the LCI a^* values (ρ = 0.41, P < 0.001). Severe IM significantly decreased the LCI b^* values compared with mild and moderate IM (P = 0.02, P < 0.001).

Conclusion

LCI quantitatively visualizes the superficial vascularity of cancer lesions and the presence of IM of the background mucosa in H. pylori-negative patients. It is a potential noninvasive tool for gastric cancer risk stratification and early detection.

References

1. Kato M, Ono S, Kawada K et al. Diagnostic performance of linked color imaging for gastric cancer by Helicobacter pylori infection status: a subanalysis of the large-scale, multicenter randomized controlled trial LCI-FIND. Helicobacter 2024; 29: e1308.
2. Kuehni RG. Color-tolerance data and the tentative CIE 1976 L a b formula. J Opt Soc Am 1976; 66: 497–500.

Disclosure

Shoko Ono has received lecture and/or consulting fees from Fujifilm.