Pradeep Bhandari

We appreciate the interest from Fernández-Esparrach et al. in our manuscript titled “Predictors of long-term outcomes of endoscopic submucosal dissection of early gastric neoplasia in the West: a multicenter study” [1]. Our data were based on the latest Japanese criteria (5th edition) [2] at the time of data analysis and manuscript preparation. In our manuscript (Supplementary Table 2s), we demonstrated the differential distribution of patients in our cohort according to both the 5th edition and the preceding 4th edition guidelines. This demonstrated the migration of more patients from the expanded criteria (based on the 4th edition) to the absolute criteria (based on the 5th edition), and highlighted the importance of analyzing the data based on the latest available guidelines and evidence. The Japan Clinical Oncology Group study (JCOG1009/1010) [3], published in 2021, concluded that endoscopic submucosal dissection (ESD) can be a curative and less invasive treatment for undifferentiated cancers <20mm, paving the way to moving this population of patients from the expanded category to the absolute category in the latest Japanese guidelines (6th edition) published in 2023 [4]. Interestingly, only one patient in our cohort would have been in the expanded criteria group based on the 5th edition guidelines (undifferentiated pT1a lesions <20mm), making it very unlikely that our results would have been different if the analysis had been based on the 6th edition guidelines. It seems that the distribution of patients in our series by indication criteria in general, and the lack of patients in the expanded group in particular, was more indicative of the future direction of patient selection for gastric ESD than in other Western series. We would, however, agree with the authors in that gastric ESD in the West should be restricted to well-trained endoscopists to ensure comparable outcomes to those in Japan, and that more studies will be needed in the future to further assess the outcomes of gastric ESD in the West in view of the latest available Japanese guidelines. Article published online: 23 April 2024 © 2024. Thieme. All rights reserved. Georg Thieme Verlag KG Rüdigerstraße 14, 70469 Stuttgart, Germany

We thank Shiratori et al. for their interest in our manuscript [1]. We analyzed our data according to the indication criteria of the 5th edition of the Japanese guidelines [2], as this was the latest edition at the time of data analysis and manuscript preparation. Since then, the 6th edition Japanese guidelines [3] have been published, in which undifferentiated pT1a lesions <20mm were moved from the expanded criteria (based on 5th edition guidelines) to the absolute criteria category. However, in our cohort we had only one patient fulfilling these criteria (undifferentiated pT1a <20mm), so we believe the re-analysis of our cohort based on the 6th edition guidelines would not produce significantly different results related to this group of patients. Regarding the study population, we did not include patients with incomplete endoscopic submucosal dissection (ESD) in our cohort. Given the setting of the regional tertiary units that participated in the study, we agree there will certainly be some patients in the source population (including referring centers) who were eligible for ESD but opted for a different treatment (e.g. surgery) or no treatment based on personal wishes or other factors. However, we did not include this in our analysis because the main focus of our study was to look at the technical and oncosurgical outcomes of ESD in a Western setting. We agree with the authors, however, that it would be interesting to gather some insight into this aspect in the West, and we hope that future Western studies may shed more light on this. The study was indeed performed at expert high-volume centers, so it may not reflect ESD outcomes from less experienced endoscopists. However, as access to ESD is still largely limited to only a few expert units in Europe, and indeed across the Western world, we still believe the outcomes from our study reflect the current practice in Europe. The question about ESD training in the West is a big and important one, and is beyond the scope of this limited letter, but we refer readers to the European Society of Gastrointestinal Endoscopy curriculum for ESD training [4], in which the authors of our manuscript are generally in agreement. Given the different healthcare settings and systems in place, there will certainly be some differences in post-ESD management pathways and protocols in Europe compared with the Far East and North America. Most patients in our cohort were only observed overnight and were discharged the next morning with clear dietary advice and appropriate guidance on medications (e.g. proton pump inhibitor medication, restarting anticoagulation or antiplatelet therapy when appropriate). We are not aware of any good quality data to suggest that a more prolonged admission post-ESD reduces the risk of complications. We agree with the authors, however, of the need to further improve R0 resection rates in the West, and we believe this can be achieved mainly through better training on advanced endoscopic assessment with enhanced-imaging techniques to improve the ability of Western endoscopists to delineate subtle and flat gastric neoplasia. Article published online: 23 April 2024 © 2024. Thieme. All rights reserved. Georg Thieme Verlag KG Rüdigerstraße 14, 70469 Stuttgart, Germany

Background This study aimed to determine long-term outcomes of gastric endoscopic submucosal dissection (ESD) in Western settings based on the latest Japanese indication criteria, and to examine predictors of outcomes and complications. Methods Data were collected from consecutive patients undergoing gastric ESD at four participating centers from 2009 to 2021. Retrospective analysis using logistic regression and survival analysis was performed. Results 415 patients were included (mean age 71.7 years; 56.4 % male). Absolute indication criteria (2018 guideline) were met in 75.3 % of patients. Median follow-up was 52 months. Post-resection histology was adenocarcinoma, high grade dysplasia, and low grade dysplasia in 49.9 %, 22.7 %, and 17.1 %, respectively. Perforation, early and delayed bleeding occurred in 2.4 %, 4.3 %, and 3.4 %, respectively. Rates of en bloc and R0 resection, and recurrence on first endoscopic follow-up were 94.7 %, 83.4 %, and 2.7 %, respectively. Relative indication (2018 guideline) for ESD was associated with R1 outcome (P = 0.02). Distal location (P = 0.002) and increased procedure time (P = 0.04) were associated with bleeding, and scarring (P = 0.009) and increased procedure duration (P = 0.003) were associated with perforation. Recurrence-free survival at 2 and 5 years was 94 % and 83 %, respectively. Conclusion This is the largest Western multicenter cohort and suggests that gastric ESD is safe and effective in the Western setting. A quarter of patients fell outside the new absolute indications for ESD, suggesting that Western practice involves more advanced lesions. We identified the predictors of complications, which should help to inform future Western practice and research.

Over the last 10 years, there have been considerable changes in how we manage Barrett’s neoplasia, with the shift away from conventional surgery and moving toward endotherapy for treating dysplasia and early cancer. In this editorial, we will review these changes and look forward to the possible developments which may occur over the next decade.

Direct cholangioscopy has been possible since the 1970s [1] but the reliability of the intubation of the common bile duct (CBD) and second-order ducts has limited the applicability of the technique. One of the limitations to accessing the ducts is the acute angulation between the duodenum and the CBD [2]. Various methods have been employed to access the ducts including mother-and-baby endoscopes and balloon assisted intubation [3]. Mother-and-baby systems are expensive, require additional equipment, and provide poorer quality images than standard endoscopes. Balloon-assisted intubation carries a risk of damage to the CBD, and requires specialist equipment with an associated learning curve [4]. We have developed a novel technique that involves the use of a standard stiff wire (SMGW, Marflow AG, Switzerland) bent to the angulation of the duodenum-CBD junction ([Fig. 1]) and passed through the working channel of a standard 5.6-mm Olympus nasendoscope. The technique begins after endoscopic retrograde cholangiopancreatography (ERCP) and sphincterotomy with a nasendoscope passed orally into the duodenum with the tip directed at the sphincter of Oddi. A pre-bent stiff wire is passed through the working channel until the bend in the wire sits within the flexible portion of the endoscope. The nasendoscope is then railroaded over the pre-bent wire into the CBD by advancing the nasendoscope whilst holding the wire fixed ([Fig. 2]). Once the flexible portion of the nasendoscope is completely within the CBD, the wire can be removed to allow full use of the working channel. Using this technique, we have successfully intubated second-order ducts ([Fig. 3]) and have been able to make reliable in vivo diagnosis using high definition endoscopes, remove difficult stones ([Fig. 4]), and biopsy lesions ([Fig. 5]) under direct vision without complications. The advantages of our technique are its low cost, that no additional equipment is required, and that it has a short learning curve. More research is needed into the technique to determine its limits and the associated risks. Endoscopy_UCTN_Code_TTT_1AR_2AB

BACKGROUND: Apart from size, little is known about what makes a colonic polyp difficult to endoscopically remove. OBJECTIVE: The aim of this study was to evaluate polyp complexity by using a novel classification system and to assess how this affects success at endoscopic resection. DESIGN: This prospective cohort study was conducted at a tertiary referral center in the United Kingdom. INTERVENTIONS: Data were collected on patients referred for endoscopic resection of polyps >2 cm in size. Lesions were classified on the basis of size, morphology, site, and ease of access with the use of a novel scoring system (size/morphology/site/access). Endoscopic resection was performed to resect the lesions. Patients were followed up endoscopically to assess clinical outcomes. MAIN OUTCOME MEASURES: The primary outcomes measured were the endoscopic cure and complication rate by size/morphology/site/access grade and the cost savings of endoscopic resection over surgery. RESULTS: Endoscopic resection was performed on 220 patients (135 male) with 220 polyps, mean size of 43 mm (range, 20 mm–150 mm). Thirty-seven percent were classified as size/morphology/site/access 2 or 3; 63% were classified as the most challenging size/morphology/site/access level 4. Complete endoscopic clearance was achieved in 90% of cases with the first endoscopic resection attempt, improving to 96% with further endoscopic resection attempts. There were complications in 18 of 220 (8.1%) of cases. Complications were independent of lesion size and location but were affected by size/morphology/site/access grade (p = 0.018). Probability of clearance at first endoscopic resection attempt was affected by lesion complexity. Size/morphology/site/access 2 and 3 = 97.5 vs SMSA 4 = 87.5% (p = 0.009). Probability of cancer was not affected by size/morphology/site/access grade. For the whole cohort, endoscopic resection represented a cost saving of £726,288 ($1,123,858.05) over that of surgery. LIMITATIONS: The main limitation of this study is that it is a single-center, single-endoscopist series. CONCLUSIONS: The size/morphology/site/access scoring system is easy to use and provides valuable information on the lesion complexity and success and complication rates of endoscopic resection. This can be used for service planning, training endoscopists, and providing prognostic information for patients.

Background and study aims: Acetic acid reacts with Barrett’s mucosa to produce acetowhitening which disappears with time. The clinical significance of this is unknown. We aimed to quantify the acetowhitening time, developing an objective tool for diagnosis of neoplasia in Barrett’s esophagus. Patients and methods: Prospective cohort study in a tertiary referral center, enrolling patients undergoing surveillance of Barrett’s metaplasia or referred with suspected neoplasia. Acetic acid 2.5 % was applied to the mucosa via a spray catheter. Acetowhitening was observed and time to disappearance recorded. Targeted biopsies of any neoplasia and quadrantic 2-cm biopsies of residual Barrett’s area were then taken. Histological findings were investigated in relation to duration of acetowhitening. Results: 132 patients were examined. A receiver operating characteristic (ROC) curve was produced for identifying high risk neoplasia according to acetowhitening duration. The area under the curve (AUC) was 0.93 (0.89 – 0.97). Using a threshold of 142 seconds yielded a sensitivity for neoplasia of 98 % (95 % confidence interval [95 %CI] 89 % – 100 %) and specificity of 84 % (74 % – 91 %). The ROC curve for mucosal neoplasia (high grade dysplasia or intramucosal carcinoma) versus deep invasive cancer showed an AUC of 0.786 (0.61 – 0.96); a cutoff of 20 seconds yielded a sensitivity and specificity for invasive cancer of 67 % (35 % – 90 %) and 85 % (69 % – 95 %), respectively. Conclusion: The time to disappearance of acetowhitening can serve as a simple but very sensitive tool for the diagnosis of high risk neoplasia in Barrett’s esophagus. It can be used to distinguish mucosal neoplasia from deep invasive cancer.