Endoscopic submucosal dissection for early gastric cancer: a large-scale feasibility study

One stomach, two subtypes of carcinoma—the differences between distal and proximal gastric cancer

Gastric cancer (GC) is one of the most common malignant tumors of the digestive tract, posing a significant risk to human health. Over the past 10 years, the pathological characteristics and the prognosis of GC have been determined based on the locations of the tumors that were then classified into two types—proximal and distal GC. This review focuses on the differences in epidemiology, etiology, cell source, pathological characteristics, gene expression, molecular markers, manifestations, treatment, prognosis, and prevention between proximal and distal GC to provide guidance and a basis for clinical diagnosis and treatment.

Features of post-endoscopic submucosal dissection electrocoagulation syndrome for early gastric neoplasm

BACKGROUND AND AIM

Post-endoscopic submucosal dissection electrocoagulation syndrome (PECS) has become a common adverse event after colorectal endoscopic submucosal dissection (ESD) and esophageal ESD. However, little is known about PECS after gastric ESD. Therefore, this study aimed to investigate the clinical features of PECS after gastric ESD.

METHODS

Patients who underwent ESD for gastric cancer or adenoma between January 2016 and December 2017 were retrospectively investigated. PECS was clinically diagnosed based on the presence of upper abdominal pain and localized abdominal tenderness with a temperature of >37.5°C, without perforation. We analyzed the clinical features of PECS.

RESULTS

A total of 637 ESD cases were enrolled; PECS occurred in 32 patients (5.0%), all of whom were diagnosed on postoperative Day 1. Among PECS cases, unplanned prolongation of hospitalization or fasting period was observed in 15 patients (47%). As a result, the median durations of hospitalization and fasting period were significantly longer in PECS cases (P = 0.008 and P < 0.001, respectively); however, the mean differences were less than a day. Additionally, all PECS cases recovered with conservative treatment.

CONCLUSIONS

PECS is considered a common adverse event after gastric ESD. More than half of patients with PECS could start diets and be discharged as well as those without PECS.

Rebleeding in patients with delayed bleeding after endoscopic submucosal dissection for early gastric cancer

OBJECTIVES

Delayed bleeding is a major adverse event in endoscopic submucosal dissection (ESD) for early gastric cancer (EGC). Some patients may experience rebleeding after successful hemostasis for delayed bleeding, yet the details of rebleeding remain unclear. We aimed to clarify the frequency and risk factors of rebleeding.

METHODS

Among 11,452 patients who underwent ESD for EGC at 33 institutions in Japan between 2013 and 2016, we analyzed 489 patients showing delayed bleeding. The rate of rebleeding was investigated. Subsequently, 15 candidate variables were evaluated for their influence on the risk of rebleeding via logistic regression analysis.

RESULTS

Rebleeding occurred in 11.2% (55/489) of the enrolled patients. Multivariate analysis revealed that warfarin [odds ratio (OR), 2.71; 95% confidence interval (CI), 1.26-5.84] and a resection size >40 mm (OR, 1.99; 95% CI, 1.08-3.67) were independent risk factors for rebleeding. In the analysis of the management of warfarin after index bleeding, only warfarin discontinuation (OR, 3.66; 95% CI, 1.37-9.78) was significantly associated with rebleeding in comparison with no use of warfarin. However, many rebleeding events (75.0%) occurred following the resumption of warfarin. The rebleeding rate during discontinuation status and that in taking warfarin (continuation or resumption) were 6.1% and 20.0%, respectively.

CONCLUSIONS

Rebleeding was not a rare event in patients experiencing delayed bleeding after ESD for EGC. In addition to having a resection size >40 mm, warfarin usage placed patients at high risk for rebleeding, especially at the timing of its resumption following discontinuation as well as its continuation.

Clinical Outcomes of Endoscopic Submucosal Dissection for Early Gastric Cancer in Patients with Comorbidities

Purpose

As the rate of endoscopic resection for early gastric cancer (EGC) has increased in patients with comorbid diseases, it is necessary to elucidate the efficacy of endoscopic submucosal dissection (ESD) for EGC in patients with comorbidities. This study aimed to analyze the clinical outcomes of ESD for EGC in patients with comorbidities.

Materials and Methods

A total of 969 patients with 1,015 lesions who underwent ESD for EGC at Seoul National University Hospital between 2010 and 2014 were analyzed. The short- and long-term clinical outcomes were evaluated according to the comorbidity status.

Results

Comorbidities were observed in 558 patients (57.6%). The comorbidity group had a higher proportion of patients using antithrombotic agents (29.5% vs. 0.9%; P<0.0001). Although procedure-related complications (bleeding and perforation) were not significantly different between the two groups, the length of hospital stay was significantly longer (1.8 vs. 1.4 days, P=0.023), while survival was significantly shorter in the comorbidity group (5-year overall survival rate: 90.5% vs. 97.2%, P<0.0001; 5-year disease-specific survival rate: 97.9% vs. 100%, P=0.018; 5-year disease-free survival rate: 83.4% vs. 89.2%, P=0.007).

Conclusions

Gastric ESD can be performed in patients with comorbidities without increasing the risk of complications.

Current Status of Photodynamic Diagnosis for Gastric Tumors

Although the recent development and widespread use of image-enhanced endoscopy and magnifying endoscopy have improved endoscopic diagnosis of gastric cancer, it is somewhat complicated, requires a higher level of expertise, and is still subjective. Photodynamic endoscopic diagnosis (PDED) is based on the fluorescence of photosensitizers that accumulate in tumors, which enables objective evaluation independent of the endoscopist’s experience, and is useful for tumor detection. The objective of this work was to perform a narrative review of PDED for gastric tumors and to introduce our approach to PDED in gastric tumors in our hospital. In our review there have been case reports of PDED for gastric cancer, but its usefulness has not been established because no prospective studies evaluating its usefulness have been performed. In our previous study, 85.7% (42/49) of gastric tumors exhibited fluorescence in PDED. PDED may be useful in the diagnosis of early gastric cancer. Our previous studies were pilot studies in cancer patients; therefore, future prospective studies are required to verify the usefulness of PDED.

Peripheral Blood-Based DNA Methylation of Long Non-Coding RNA H19 and Metastasis-Associated Lung Adenocarcinoma Transcript 1 Promoters are Potential Non-Invasive Biomarkers for Gastric Cancer Detection

Introduction

The early diagnosis and detection could greatly improve the clinical outcome of gastric cancer (GC) patients. However, the non-invasive biomarkers for GC detection remain to be identified.

Method

We used online databases (GEPIA, UALCAN, Kaplan-Meier plotter, TIMER, and MEXPRESS) to explore the association between H19 or metastasis-associated lung adenocarcinoma transcript 1 (MALAT1) expression in tissues and the occurrence, development, prognosis, the levels of immune cell infiltration, and methylation of GC; the correlation between mRNA expression and DNA methylation levels of genes were also examined. Methylation levels of H19 or MALAT1 in peripheral blood were compared between 150 GC patients and 100 healthy controls (HCs). Predictive nomograms were constructed among female and male groups for GC diagnosis. The calibration curves, Hosmer–Lemeshow test, and decision curve analysis were also used to examine the nomograms’ predictive ability and clinical values.

Results

Using multiple online databases, we found that the mRNA expressions of H19 and MALAT1 in tissues were related to the occurrence of GC, and such expressions were associated with immune cell infiltration of GC and negatively correlated with DNA methylation levels of H19 and MALAT1. H19 gene, H19C island, and MALAT1B island, as well as 20 CpG sites were hypermethylated in peripheral blood of GC patients compared with HCs; similar results were also found in female and male groups (P < .05 for all). The combination of H19c3, H19c4, MALAT1b12, and age, as well as the combination of H19b7, H19c1, H19c5, and age in the nomograms could distinguish GC patients from HCs in the female group and male group, respectively.

Conclusion

We found statistically significant hypermethylation of H19 and MALAT1 promoters in GC patients, and meaningful sensitivity and specificity of MALAT1 and H19 methylation in discriminating GC and HCs were observed in both female and male groups, which indicates that the peripheral blood-based DNA methylation of H19 and MALAT1 could act as potential non-invasive biomarkers for the diagnosis of GC.

Correlation between healing type of lesion and recurrence in gastric neoplastic lesions after endoscopic submucosal dissection

BACKGROUND/AIMS

To date, there are few reports on the clinical association between healing pattern of lesion and local recurrence after endoscopic resection (ER). We examined the risk factors associated with local recurrence after endoscopic submucosal dissection (ESD) and the correlation between healing type of lesion and recurrence.

MATERIALS AND METHODS

We retrospectively analyzed medical records of 293 patients who underwent ESD of early gastric cancer or gastric adenoma between April 2010 and January 2012. We analyzed the relationship among factors such as age, location of lesion, size, pathologic diagnosis, presence of Helicobacter pylori (H. pylori), and healing types of ulcers in patients with local recurrence through follow-up endoscopic surveillance (1, 6, and 12 months after ESD).

RESULTS

We analyzed 141 patients except for patients who had not undergone surveillance endoscopy, H. pylori test, and ambiguous healing patterns. There were no significant correlations between local recurrences concerning sex, age, tumor size, location, and pathologic diagnosis. When the healing type of the ulcer was divided into hypertrophic polypoid type (9 cases (6.4%)), scar type (122 cases (86.5%)), and nodular type (10 cases (7.1%)), the scar type was found to be most common. A total of eight patients (5.7%) developed local recurrence, of which five were of nodular type and statistically significant (p=0.000).

CONCLUSION

The most common type of ulcer healing was scar type after ESD, but nodular type was associated with local recurrence. When we perform follow-up endoscopy after ESD, we should pay attention to the lesion that has nodular change of mucosal surface.

Quantifying early gastric cancer in Australia: What is the opportunity for gastric endoscopic submucosal dissection?

BACKGROUND AND AIMS

Endoscopic submucosal dissection (ESD) is the recommended treatment for early gastric cancer (EGC). However, there are challenges in attaining expertise in ESD in countries where the incidence of gastric cancer and proportion diagnosed at an early stage of disease are relatively low. This study aims to establish the proportion of gastric cancer meeting histological criteria for EGC, which may be suitable for ESD, in a Western population.

METHODS

Gastric cancers reported to the Victorian Cancer Registry between January 2011 and December 2016 were analyzed. EGC was defined as tumor confined to mucosa (T1a) or submucosa (T1b). Histology reports were analyzed using Japanese and European guidelines to identify potential ESD candidates. Criteria for extended ESD were based on grade of differentiation, tumor depth, lymphovascular and perineural invasion, and ulceration.

RESULTS

Twenty percent of 1217 gastric cancers was EGC (237 cases), with detailed histopathology reports suitable for evaluating ESD criteria recorded in 182 cases. Standard and extended ESD criteria were met in 46% (84/182) and 75% (132/182), respectively. Actual treatment of the 237 EGC was endoscopic in 14% (n = 33) and surgery in 86% (n = 204). Endoscopically treated EGCs were more likely to be stage T1a and located in the proximal stomach.

CONCLUSIONS

EGCs represented 20% of reported gastric adenocarcinomas with the majority fulfilling criteria for ESD. ESD should be considered in the management algorithm and discussed at tumor board meetings involving interventional endoscopists. To increase utilization of ESD, systems need to be implemented to improve training, accreditation, and access to ESD.

Timing of bleeding and thromboembolism associated with endoscopic submucosal dissection for gastric cancer in Japan

BACKGROUND AND AIM

This study aimed to reveal the timing of bleeding and thromboembolism associated with endoscopic submucosal dissection (ESD) for early gastric cancer (EGC).

METHODS

We retrospectively reviewed  10,320 patients who underwent ESD for EGC during November 2013-October 2016. We evaluated overall bleeding rates and their inter-group differences. Factors associated with early/late (cut-off 5 days) bleeding and thromboembolism frequency and its association with the intake of antithrombotic agents were investigated.

RESULTS

Overall, the post-ESD bleeding rate was 4.7% (489/10 320); the median time to post-ESD bleeding was 4 days. The post-ESD bleeding rates were 3.2%, 8.7%, 15.5%, and 29.9% in those not taking antithrombotic agents, those taking antiplatelet agents, those taking anticoagulants (ACs), and those taking antiplatelet agents and ACs. Warfarin (odds ratio [OR], 9.16), direct oral ACs (OR, 4.16), chronic kidney disease with hemodialysis (OR, 2.93), thienopyridine (OR, 2.25), aspirin (OR, 1.66), tumor size >30 mm (OR, 1.86), multiple tumors' resection (OR, 1.54), and tumor in the lower third of the stomach (OR, 1.40) were independent risk factors for early bleeding. The independent risk factors for late bleeding were direct oral ACs (OR, 7.42), chronic kidney disease with hemodialysis (OR, 4.99), warfarin (OR, 3.90), thienopyridine (OR, 3.09), liver cirrhosis (OR, 2.43), cilostazol (OR, 1.93), aspirin (OR, 1.92), ischemic heart disease (OR, 1.77), and male sex (OR, 1.65). There were three (0.03%) thromboembolic events (cerebral infarction = 2, transient ischemic attack = 1).

CONCLUSION

We revealed the timing of bleeding and risk factors for early/late bleeding and showed the thromboembolism frequency associated with ESD for EGC.

Using machine-learning algorithms to identify patients at high risk of upper gastrointestinal lesions for endoscopy

BACKGROUND AND AIM

Endoscopic screening for early detection of upper gastrointestinal (UGI) lesions is important. However, population-based endoscopic screening is difficult to implement in populous countries. By identifying high-risk individuals from the general population, the screening targets can be narrowed to individuals who are in most need of an endoscopy. This study was designed to develop an artificial intelligence (AI)-based model to predict patient risk of UGI lesions to identify high-risk individuals for endoscopy.

METHODS

A total of 620 patients (from 5300 participants) were equally allocated into 10 parts for 10-fold cross validation experiments. The machine-learning predictive models for UGI lesion risk were constructed using random forest, logistic regression, decision tree, and support vector machine (SVM) algorithms. A total of 48 variables covering lifestyles, social-economic status, clinical symptoms, serological results, and pathological data were used in the model construction.

RESULTS

The accuracies of the four models were between 79.3% and 93.4% in the training set and between 77.2% and 91.2% in the testing dataset (logistics regression: 77.2%; decision tree: 87.3%; random forest: 88.2%; SVM: 91.2%;). The AUCs of four models showed impressive predictive ability. Comparing the four models with the different algorithms, the SVM model featured the best sensitivity and specificity in all datasets tested.

CONCLUSIONS

Machine-learning algorithms can accurately and reliably predict the risk of UGI lesions based on readily available parameters. The predictive models have the potential to be used clinically for identifying patients with high risk of UGI lesions and stratifying patients for necessary endoscopic screening.

Neoadjuvant Chemotherapy Versus Direct Surgery for Locally Advanced Gastric Cancer With Serosal Invasion (cT4NxM0): A Propensity Score-Matched Analysis

Background

For locally advanced gastric cancer (LAGC) with serosal invasion (cT4NxM0), adjuvant chemotherapy (AC) after D2 gastrectomy is the standard therapy in Asia. However, perioperative chemotherapy (PCT) combined with D2 gastrectomy is mostly suggested in Europe and America. As a part of PCT, the value of neoadjuvant chemotherapy (NAC) is unclear. We investigated whether NAC could further improve survival and other outcomes for these patients.

Methods

Patients with cT4NxM0 gastric cancer who underwent D2 gastrectomy were analyzed. The patients were divided into two groups based on whether they received NAC: the neoadjuvant chemotherapy (NAC) and direct surgery (S) groups. After propensity score matching (1:1 ratio), survival and perioperative outcomes were analyzed between the two groups.

Results

A total of 902 patients met all the eligibility criteria and were enrolled. After propensity score matching, 221 matched pairs of patients were identified. The median overall survival (OS) and disease-free survival (DFS) of all patients were 75.10 and 43.67 months, respectively. The median OS of patients in the NAC and S groups were undefined and 29.80 months, respectively (P<0.0001). The median DFS of patients in the NAC and S groups were undefined and 22.60 months (P<0.0001). There were no significant differences in the radical degrees of operation between the two groups (P=0.07). However, there were significant differences in postoperative hospital stay (P<0.001) and complications (P=0.037) between the two groups.

Conclusion

This study suggested NAC can further improve prognosis and prevent recurrence in LAGC (cT4NxM0) patients. NAC is feasible and safe for LAGC (cT4NxM0) patients, and does not increase the risk of perioperative surgery.

Efficacy of Sodium Carboxymethylcellulose Compared to Sodium Hyaluronate as Submucosal Injectant for Gastric Endoscopic Submucosal Dissection: A Randomized Controlled Trial

INTRODUCTION

Sodium hyaluronate (SH) is a useful submucosal injectant for gastric endoscopic submucosal dissection (ESD). On the other hand, sodium carboxymethylcellulose (SCMC), which has high viscosity, has also been applied clinically. We evaluated the efficacy of SCMC compared to that of SH in gastric ESD.

METHODS

A prospective randomized controlled trial was conducted to assess the efficacy of 1.0% SCMC as the injectant (SCMC group) compared to 0.4% SH (SH group) for ESD of gastric neoplasms. The primary end point was the procedure time of ESD. Secondary end points were treatment outcomes such as en bloc and R0 resection rates, number of hemostases, amount of injectant, ease of treatment (visual analog scale, 1-10 points), adverse events, and rate of ulcer healing 8 weeks after ESD.

RESULTS

A total of 60 patients were enrolled between October 2014 and October 2018, and 30 patients were allocated in each group. The procedure time (mean ± SD, minutes) was not significantly different between the SCMC (74.7 ± 54.5) and SH groups (67.1 ± 41.4) (p = 0.547). Furthermore, there were no differences between the 2 groups in terms of en bloc and R0 resection rates, number of hemostases, amount of injectant, ease of treatment, and rate of ulcer healing. No serious adverse events were observed in either group.

CONCLUSION

SCMC was comparable to SH in terms of procedure time, treatment outcome, and ease and safety of treatment in gastric ESD. Further studies are needed to demonstrate the differences between the 2 injectants.

Effect of administration of a proton pump inhibitor for ulcerative differentiated early gastric cancer prior to endoscopic submucosal dissection

OBJECTIVES

Predicting the depth of invasion for early gastric cancer (EGC) with ulcerative findings may prove difficult. The purpose of this study was to evaluate the extent of ulcer healing and clinical effectiveness of proton pump inhibitor (PPI) administration for ulcerative differentiated EGC prior to endoscopic submucosal dissection (ESD).

METHODS

A total of 214 patients with ulcerative differentiated EGC who were treated by ESD were retrospectively analyzed, among whom 129 had been administered a PPI prior to ESD and 85 patients had not. The degree of ulcer healing following administration of PPI and the clinical outcome were compared between the PPI and non-PPI groups.

RESULTS

The ulcer healing rate (80.7 vs. 30.6%, P < 0.001) and complete ulcer healing rate (45.0 vs. 16.5%, P < 0.001) differed significantly between the PPI and non-PPI groups, respectively. The ESD procedure time was 86.0 (73) vs. 100.0 (68.0) min (P = 0.044). However, no significant differences were observed in the en bloc resection rate, complete resection rate, or the incidence of adverse events. Based on the multivariate regression analysis, PPI administration [odds ratio (OR) = 4.909, 95% confidence interval (CI) 2.459-9.799, P < 0.001] and mucosal cancer (OR = 9.336, 95% CI 2.693-32.362, P < 0.001) were independent predictive factors for complete ulcer healing. Partial or complete ulcer healing following PPI administration had a better predictive ability than EUS for mucosal invasion (kappa value 0.553 vs. 0.101; Youden index 0.553 vs. 0.132).

CONCLUSIONS

Partial or complete ulcer healing following PPI administration predicts differentiated EGC that is confined to the mucosa.

Does second-look endoscopy reduce the bleeding after gastric endoscopic submucosal dissection for patients receiving antithrombotic therapy?

Background

In patients with average risk of bleeding, second-look endoscopy does not reportedly reduce bleeding after gastric endoscopic submucosal dissection. However, effectiveness of second-look endoscopy for patients with a high risk of bleeding, such as those who are taking antithrombotic agents, is unclear. Hence, this study aims to clarify the effectiveness of second-look endoscopy for patients with antithrombotic therapy.

Methods

We studied 142 consecutive patients with 173 gastric epithelial neoplasms who were routinely taking antithrombotic agents and were treated by endoscopic submucosal dissection at Tonan Hospital between November 2013 and December 2019. They were classified into two groups: those with second-look endoscopy (SLE group, 69 patients with 85 lesions) and those without second-look endoscopy (non-SLE group, 73 patients with 88 lesions). The incidence of post-endoscopic submucosal dissection bleeding was compared between the SLE and non-SLE groups.

Results

There were no statistical differences in the rate of patients undergoing single antiplatelet therapy, single anticoagulant therapy, and multiple therapy between the SLE and non-SLE groups (SLE group vs. non-SLE group; 32 [46.4%], 16 [23.2%], and 21 [30.4%] patients vs. 37 [50.7%], 20 [27.4%], and 16 [21.9%] patients, respectively; p = 0.50). Post-endoscopic submucosal dissection bleeding incidence was 21.7% (15/69) and 21.9% (16/73) in the SLE and non-SLE groups, respectively, and did not significantly differ between the two groups (p = 0.98).

Conclusions

For patients taking antithrombotic agents, the incidence of post-endoscopic submucosal dissection bleeding was not reduced by second-look endoscopy.

Prognostic nutritional index is an independent prognostic factor for older patients aged ≥ 85 years treated by gastric endoscopic submucosal dissection

Background

Clinical outcomes and prognostic factors for survival after endoscopic submucosal dissection (ESD) in older patients aged ≥ 85 years with early gastric cancer (EGC) are not well defined. The aim of this study was to investigate the clinical outcomes and prognostic factors for survival after ESD in older patients aged ≥ 85 years with EGC.

Methods

Clinical outcomes of 70 patients aged ≥ 85 years with EGC treated with ESD were evaluated retrospectively. Prognostic factors for overall survival (OS) were analyzed with the Kaplan–Meier method and a Cox proportional hazards model.

Results

During the follow-up period, 33 patients died from any cause, none of whom died from gastric cancer. OS probability after 3 years was 90.0%. Univariate analyses revealed that a neutrophil/lymphocyte ratio ≥ 2.6, a prognostic nutritional index (PNI) < 42.5 and low serum albumin value (< 3.5 g/dl) were associated with poor OS. Cox multivariate analysis revealed low PNI (< 42.5) to be an independent prognostic factor associated with OS (hazard ratio; 3.40, 95% confidence interval; 1.47–7.86, P = 0.004).

Conclusions

PNI may be a useful parameter for making the decision to perform ESD for older patients aged ≥ 85 years with EGC.

New Closure Method Using Loop and Open-Close Clips after Endoscopic Submucosal Dissection of Stomach and Colon Lesions

Endoscopic submucosal dissection (ESD) and en bloc resection of stomach and colon tumors have become common. However, mucosal defects resulting from ESD may cause delayed bleeding and perforation. To prevent adverse events, we developed a new clip closure technique, namely, the loop and open–close clip closure method (LOCCM), and aimed to examine its efficacy after ESD for stomach and colon tumors. The LOCCM uses loop and open–close clips. Here, the open–close clip was used to grasp the loop to bring it to the edge of the post-ESD mucosal defect. Another clip with a loop was then inserted into the opposite edge and clipped to the contralateral mucosa to pull both edges together. Once apposed, additional clips facilitated complete closure. The LOCCM was performed in 19 patients after ESD at Tottori University between October 2020 and March 2021. The outcomes retrospectively analyzed were the LOCCM success and adverse event rates. The complete closure rate using LOCCM was 89.5% and none of the patients had post-ESD bleeding or perforation. The results show that LOCCM is an effective and safe closure technique for mucosal defects after stomach and colon ESD to prevent bleeding and perforation.

Long- and short-term outcomes of early gastric cancer after endoscopic resection: a retrospective study from China

Background and study aims  The aim of the study was to evaluate short- and long-term outcomes of endoscopic submucosal dissection (ESD) for early gastric cancer (EGC) in China because no study has yet been conducted to confirm its effectiveness in EGC in China. Patients and methods  A total of 570 EGC samples from 537 patients were collected for evaluation of en bloc, complete, and curative resection using ESD. Data from 302 patients with at least 3 years of active follow-up were collected for analysis of recurrence of EGC and occurrence of metachronous GC (MGC). Short- and long-outcomes of mixed-type and pure differentiated EGC were also compared. Results  En bloc resection rates of 96.0 %, 98.7 %, and 95.2 %, complete resection rates of 91.2 %, 96.6 % and 90.8 %, and curative resection rates of 83.0 %, 96.2 % and 88.2 % were achieved in all EGCs included in the study, those with absolute indication, and those with expanded indication, respectively. As a long-term outcome, recurrence was observed in 1.3 % of patients, 3-year and 5-year recurrence rates being 0.7 % and 1.2 %, respectively. Thirteen patients (4.3 %) exhibited MGCs during follow-up, all of which were resected in a second ESD. Conclusions  The effectiveness of ESD for EGC in China was confirmed, with satisfactory short- and long-term outcomes. With scheduled follow-up, the outcomes for mixed-type EGC can be similar to those for pure differentiated EGC after complete resection without development of lymphovascular invasion.

Fundamentals, Diagnostic Capabilities and Perspective of Narrow Band Imaging for Early Gastric Cancer

The development of image-enhanced endoscopy has dramatically improved the qualitative and quantitative diagnosis of gastrointestinal tumors. In particular, narrow band imaging (NBI) has been widely accepted by endoscopists around the world in their daily practice. In 2009, Yao et al. proposed vessel plus surface (VS) classification, a diagnostic algorithm for early gastric cancer using magnifying endoscopy with NBI (ME-NBI), and in 2016, Muto et al. proposed a magnifying endoscopy simple diagnostic algorithm for early gastric cancer (MESDA-G) based on VS classification. In addition, the usefulness of ME-NBI in the differential diagnosis of gastric cancer from gastritis, diagnosis of lesion extent, inference of histopathological type, and diagnosis of depth has also been investigated. In this paper, we narrative review the basic principles, current status, and future prospects of NBI.

Optimal procedure-related hospitalization using clinical pathway protocols following gastric endoscopic submucosal dissection

BACKGROUND

The clinical pathway (CP) protocols simplified a systematic process from hospitalization to discharge, and were conducted to achieve standardization of the treatment process as well as improve outcomes. Thus, we investigated the optimal procedure-related hospitalization period following gastric endoscopic submucosal dissection (ESD) by comparing the rate of delayed bleeding (DB) and perforation according to CP protocols.

METHODS

We retrospectively enrolled 630 patients who underwent ESD for gastric dysplasia or early gastric cancer (EGC); Group A (368 patients) followed Protocol A for a hospital stay of a single night; Group B (262 patients) followed Protocol B for a hospital stay of two nights.

RESULTS

The patient characteristics were comparable between the two groups, except for pathologic diagnosis (42.1% in Group A vs. 32.1% in Group B for EGC). DB occurred in 21 patients, and there was no significant difference in the overall DB rates between Group A (12/368 = 3.3%) and Group B (9/262 = 3.4%) (P = 0.904). The DB rates were 2.5% (8/315) and 7.5% (4/53) in Group A, and 2.7% (6/223) and 7.7% (3/39) in Group B, without and with the use of antiplatelets, respectively, and 33.3% (1/3) in Group A and 50.0% (1/2) in Group B with the use of dual antiplatelets. DB developed at various intervals post-discharge from 2 to 17 days, and was successfully controlled by endoscopic hemostasis in most cases. There were no deaths or surgeries required as a result of uncontrolled DB and no postoperative delayed perforation occurred.

CONCLUSIONS

The CP protocols with a one-night hospitalization following gastric ESD decreased the hospital stay and did not influence postoperative complications compared to those with two-night hospitalizations.

Deep learning analysis of the primary tumour and the prediction of lymph node metastases in gastric cancer

BACKGROUND

Lymph node metastasis (LNM) in gastric cancer is a prognostic factor and has implications for the extent of lymph node dissection. The lymphatic drainage of the stomach involves multiple nodal stations with different risks of metastases. The aim of this study was to develop a deep learning system for predicting LNMs in multiple nodal stations based on preoperative CT images in patients with gastric cancer.

METHODS

Preoperative CT images from patients who underwent gastrectomy with lymph node dissection at two medical centres were analysed retrospectively. Using a discovery patient cohort, a system of deep convolutional neural networks was developed to predict pathologically confirmed LNMs at 11 regional nodal stations. To gain understanding about the networks' prediction ability, gradient-weighted class activation mapping for visualization was assessed. The performance was tested in an external cohort of patients by analysis of area under the receiver operating characteristic (ROC) curves (AUC), sensitivity and specificity.

RESULTS

The discovery and external cohorts included 1172 and 527 patients respectively. The deep learning system demonstrated excellent prediction accuracy in the external validation cohort, with a median AUC of 0·876 (range 0·856-0·893), sensitivity of 0·743 (0·551-0·859) and specificity of 0·936 (0·672-0·966) for 11 nodal stations. The imaging models substantially outperformed clinicopathological variables for predicting LNMs (median AUC 0·652, range 0·571-0·763). By visualizing nearly 19 000 subnetworks, imaging features related to intratumoral heterogeneity and the invasive front were found to be most useful for predicting LNMs.

CONCLUSION

A deep learning system for the prediction of LNMs was developed based on preoperative CT images of gastric cancer. The models require further validation but may be used to inform prognosis and guide individualized surgical treatment.

Comparing a conventional and a spring-and-loop with clip traction method of endoscopic submucosal dissection for superficial gastric neoplasms: a randomized controlled trial (with videos)

BACKGROUND AND AIMS

Several traction methods have sought to overcome the technical difficulties of endoscopic submucosal dissection (ESD). However, traction direction has remained limited in most of these methods, with lack of clarity about the optimal method and traction direction for gastric ESD. A spring-and-loop with clip (SLC) has been developed as a multidirectional traction device. Here, we investigated whether SLC traction-assisted ESD (SLC-ESD) improved procedure-related outcomes compared with conventional ESD (C-ESD) among patients with superficial gastric neoplasms.

METHODS

This single-center randomized controlled trial included patients with superficial gastric neoplasms undergoing SLC-ESD or C-ESD between October 2018 and December 2019. Using the multidirectional traction function, we set traction vertical to the gastric wall for SLC-ESD. The primary outcome was the median procedure time for gastric ESD.

RESULTS

The SLC-ESD and C-ESD groups comprised 40 patients each, and all the enrolled patients underwent the assigned treatment. The median ESD procedure time was significantly shorter in the SLC-ESD group (29.1 minutes) than in the C-ESD group (52.6 minutes; P = .005). SLC had a mean attachment time of 1.82 minutes. En bloc resection was achieved without perforation in all the patients in both groups.

CONCLUSIONS

Our findings suggest that SLC-ESD reduces gastric ESD procedure time without increasing the risk of perforation and that the vertical direction to the gastric wall is the appropriate traction direction for gastric ESD. (Clinical trial registration number: UMIN 000034533.).

A deep learning-based system for identifying differentiation status and delineating the margins of early gastric cancer in magnifying narrow-band imaging endoscopy

BACKGROUND : Accurate identification of the differentiation status and margins for early gastric cancer (EGC) is critical for determining the surgical strategy and achieving curative resection in EGC patients. The aim of this study was to develop a real-time system to accurately identify differentiation status and delineate the margins of EGC on magnifying narrow-band imaging (ME-NBI) endoscopy. METHODS : 2217 images from 145 EGC patients and 1870 images from 139 EGC patients were retrospectively collected to train and test the first convolutional neural network (CNN1) to identify EGC differentiation status. The performance of CNN1 was then compared with that of experts using 882 images from 58 EGC patients. Finally, 928 images from 132 EGC patients and 742 images from 87 EGC patients were used to train and test CNN2 to delineate the EGC margins. RESULTS : The system correctly predicted the differentiation status of EGCs with an accuracy of 83.3 % (95 % confidence interval [CI] 81.5 % - 84.9 %) in the testing dataset. In the man - machine contest, CNN1 performed significantly better than the five experts (86.2 %, 95 %CI 75.1 % - 92.8 % vs. 69.7 %, 95 %CI 64.1 % - 74.7 %). For delineating EGC margins, the system achieved an accuracy of 82.7 % (95 %CI 78.6 % - 86.1 %) in differentiated EGC and 88.1 % (95 %CI 84.2 % - 91.1 %) in undifferentiated EGC under an overlap ratio of 0.80. In unprocessed EGC videos, the system achieved real-time diagnosis of EGC differentiation status and EGC margin delineation in ME-NBI endoscopy. CONCLUSION : We developed a deep learning-based system to accurately identify differentiation status and delineate the margins of EGC in ME-NBI endoscopy. This system achieved superior performance when compared with experts and was successfully tested in real EGC videos.

A Novel Model Based on Deep Convolutional Neural Network Improves Diagnostic Accuracy of Intramucosal Gastric Cancer (With Video)

Background and Aims

Prediction of intramucosal gastric cancer (GC) is a big challenge. It is not clear whether artificial intelligence could assist endoscopists in the diagnosis.

Methods

A deep convolutional neural networks (DCNN) model was developed via retrospectively collected 3407 endoscopic images from 666 gastric cancer patients from two Endoscopy Centers (training dataset). The DCNN model’s performance was tested with 228 images from 62 independent patients (testing dataset). The endoscopists evaluated the image and video testing dataset with or without the DCNN model’s assistance, respectively. Endoscopists’ diagnostic performance was compared with or without the DCNN model’s assistance and investigated the effects of assistance using correlations and linear regression analyses.

Results

The DCNN model discriminated intramucosal GC from advanced GC with an AUC of 0.942 (95% CI, 0.915–0.970), a sensitivity of 90.5% (95% CI, 84.1%–95.4%), and a specificity of 85.3% (95% CI, 77.1%–90.9%) in the testing dataset. The diagnostic performance of novice endoscopists was comparable to those of expert endoscopists with the DCNN model’s assistance (accuracy: 84.6% vs. 85.5%, sensitivity: 85.7% vs. 87.4%, specificity: 83.3% vs. 83.0%). The mean pairwise kappa value of endoscopists was increased significantly with the DCNN model’s assistance (0.430–0.629 vs. 0.660–0.861). The diagnostic duration reduced considerably with the assistance of the DCNN model from 4.35s to 3.01s. The correlation between the perseverance of effort and diagnostic accuracy of endoscopists was diminished using the DCNN model (r: 0.470 vs. 0.076).

Conclusions

An AI-assisted system was established and found useful for novice endoscopists to achieve comparable diagnostic performance with experts.

A review on recent advancements in diagnosis and classification of cancers using artificial intelligence

Artificial intelligence has illustrated drastic changes in radiology and medical imaging techniques which in turn led to tremendous changes in screening patterns. In particular, advancements in these techniques led to the development of computer aided detection (CAD) strategy. These approaches provided highly accurate diagnostic reports which served as a "second-opinion" to the radiologists. However, with significant advancements in artificial intelligence strategy, the diagnostic and classifying capabilities of CAD system are meeting the levels of radiologists and clinicians. Thus, it shifts the CAD system from second opinion approach to a high utility tool. This article reviews the strategies and algorithms developed using artificial intelligence for the foremost cancer diagnosis and classification which overcomes the challenges in the traditional method. In addition, the possible direction of AI in medical aspects is also discussed in this study.

Traction-assisted endoscopic submucosal dissection reduces procedure time and risk of serious adverse events: a systematic review and meta-analysis

BACKGROUND AND AIMS

Conventional endoscopic submucosal dissection (C-ESD) is a technically demanding procedure with prolonged procedure times and higher risk of adverse events. To overcome the procedural difficulty of ESD, several traction-assisted techniques (T-ESD) have been developed to improve visualization of the submucosa in hopes to facilitate safe and effective dissection. The aim of this study was to conduct a meta-analysis that compares short-term outcomes (30-day) of T-ESD to C-ESD.

METHODS

Clinical studies published up to April 2020 comparing the efficacy and safety of T-ESD and C-ESD were identified using electronic bibliographic searches. Both randomized controlled trials and observational studies were included. Outcomes of interests were procedure time, rates of en bloc and R0 resection, and rates of adverse events. Fixed effect and random effect model were used to calculate pooled mean difference for continuous variables and risk differences (RDs) for categorical variables.

RESULTS

Twenty-three studies with 2574 patients were included in this meta-analysis, with a total of 2582 lesions (1292 T-ESD and 1290 C-ESD). Pooled estimates of T-ESD showed shorter procedure times (weighted mean difference = -20.35 min, 95% CI -27.51 to -13.19, p < 0.001), higher R0 resection rates (RD 0.04, 95% CI 0.01-0.06, p = 0.004) and lower perforation rates (RD -0.03, 95% CI -0.04 to -0.01, p =  < 0.0001). No significant differences were seen in en bloc rates and bleeding risk between the two groups.

CONCLUSIONS

Traction-assisted ESD results in shorter procedure time, improved R0 resection rates and lower risk of perforation as compared to conventional ESD.

Lactobionic acid-modified chitosan thermosensitive hydrogels that lift lesions and promote repair in endoscopic submucosal dissection

To develop a biomaterial to lift the lesion and promote wound healing in endoscopic submucosal dissection (ESD), we used lactobionic acid (LA) to improve the water solubility of chitosan (CS) and prepared a new three-phase hydrogel system with lactobionic acid-modified chitosan/chitosan/β-glycerophosphate (CSLA/CS/GP). The results indicated that the hydrogel retains temperature-sensitive properties, and CSLA obviously improved the low-temperature fluidity of the hydrogel precursor solution, enabling injection of the hydrogel by endoscopic needle. The mechanical strength and bio-adhesion of the hydrogels were also improved by the addition of CSLA and the hydrogels could be maintained in acidic environment for a few days and exhibit greater protection of cells. The CSLA/CS/GP hydrogels show good cytocompatibility. The heights of cushions elevated by CSLA/CS/GP hydrogels remained ∼ 60 % 2 h post-injection in porcine stomach models. Given the unique characteristics of these materials, the CSLA/CS/GP thermo-sensitive hydrogel is a promising intraoperative biomaterial in ESD.

Efficacy and safety of endoscopic submucosal dissection for gastric tube cancer: A multicenter retrospective study

BACKGROUND

Recent improvements in the prognosis of patients with esophageal cancer have led to the increased occurrence of gastric tube cancer (GTC) in the reconstructed gastric tube. However, there are few reports on the treatment results of endoscopic submucosal dissection (ESD) for GTC.

AIM

To evaluate the efficacy and safety of ESD for GTC after esophagectomy in a multicenter trial.

METHODS

We retrospectively investigated 48 GTC lesions in 38 consecutive patients with GTC in the reconstructed gastric tube after esophagectomy who had undergone ESD between January 2005 and December 2019 at 8 institutions participating in the Okayama Gut Study group. The clinical indications of ESD for early gastric cancer were similarly applied for GTC after esophagectomy. ESD specimens were evaluated in 2-mm slices according to the Japanese Classification of Gastric Carcinoma with curability assessments divided into curative and non-curative resection based on the Gastric Cancer Treatment Guidelines. Patient characteristics, treatment results, clinical course, and treatment outcomes were analyzed.

RESULTS

The median age of patients was 71.5 years (range, 57-84years), and there were 34 men and 4 women. The median observation period after ESD was 884 d (range, 8-4040 d). The median procedure time was 81 min (range, 29-334 min), the en bloc resection rate was 91.7% (44/48), and the curative resection rate was 79% (38/48). Complications during ESD were seen in 4% (2/48) of case, and those after ESD were seen in 10% (5/48) of case. The survival rate at 5 years was 59.5%. During the observation period after ESD, 10 patients died of other diseases. Although there were differences in the procedure time between institutions, a multivariate analysis showed that tumor size was the only factor associated with prolonged procedure time.

CONCLUSION

ESD for GTC after esophagectomy was shown to be safe and effective.

Efficacy and safety of grasping forceps-assisted endoscopic resection for gastric neoplasms: A multi-centre retrospective study

BACKGROUND

Endoscopic submucosal dissection (ESD) is widely accepted for early gastric cancer (EGC) without lymph node metastasis, although ESD is challenging, even for small lesions, in the greater curvature (GC) of the upper (U) and middle (M) thirds of the stomach. Grasping forceps-assisted endoscopic resection (GF-ER) is a type of endoscopic mucosal resection that is performed via a double-channel endoscope.

AIM

To investigate the safety and efficacy of GF-ER vs ESD in the GC of the stomach’s U and M regions.

METHODS

We retrospectively reviewed the medical records of 506 patients who underwent ER of 522 EGC lesions in the stomach’s U and M regions in three institutions between January 2016 and May 2020. Nine lesions from eight patients who underwent GF-ER for EGC (the GF-ER group) were compared to 63 lesions from 63 patients who underwent ESD (the ESD group). We also performed a subgroup analysis of small lesions (≤ 10 mm) in 6 patients (7 lesions) from the GF-ER group and 20 patients (20 lesions) from the ESD group.

RESULTS

There were no statistically significant differences between the GF-ER and ESD groups in the en bloc resection rates (100% vs 100%) and the R0 resection rates (100% vs 98.4%). The median procedure time in the GF-ER group was shorter than that in the ESD group (4.0 min vs 55.0 min, P < 0.01). There were no adverse events in the GF-ER group, although five perforations (8.0%) and 1 case of postoperative bleeding (1.6%) were observed in the ESD group. When we only considered lesions that were ≤ 10 mm, the median procedure time in the GF-ER group was still shorter than that in the ESD group (4.0 min vs 35.0 min, P < 0.01). There were no adverse events in the GF-ER group, although 1 case of perforation (1.6%) were observed in the ESD group.

CONCLUSION

These findings suggest that GF-ER may be an effective therapeutic option for small lesions in the GC of the stomach’s U and M regions.

Clinical outcomes of early gastric cardiac cancer treated with endoscopic submucosal dissection in patients with different indications

BACKGROUND

Endoscopic submucosal dissection (ESD) has been accepted as a standard treatment for early gastric cardiac cancer (EGCC). Here, we investigate the clinical outcomes of the EGCC patients who underwent ESD in different indications.

METHODS

From January 2011 to October 2019, we enrolled 502 EGCC lesions from 495 patients which were resected by ESD at our center. We retrospectively analyzed the short-term and long-term clinical outcomes among different indication groups.

RESULTS

The number of the patients in the absolute indication (AI), expanded indication (EI) and beyond the expanded indication (BEI) groups was 265, 137 and 93, respectively. The en bloc resection rate was 100%, 100% and 98.9% (P = 0.185). The complete resection rate was 99.3%, 98.5% and 74.5%, respectively (P < 0.001). During a median follow-up of 48.1 months, the lymph node metastasis rate was 0%, 0% and 2.3% (P < 0.001). The distant metastasis rate was 0.4%, 0% and 2.3% (P = 0.150). The five-year disease-specific survival rate in the BEI group was 96.6% (P = 0.016), compared to 99.6% in the AI group and 100% in the EI group.

CONCLUSION

The efficacy for ESD patients in EI group was almost equal to the AI group. Patients in the BEI group showed generally favorable clinical outcomes and needed to be carefully checked after ESD. ESD may be an optional treatment for patients unsuitable for gastrectomy.

Characteristics of interval gastric neoplasms detected within two years after negative screening endoscopy among Koreans

Background

In Korea, where gastric cancer is highly prevalent, biennial endoscopy is recommended among individuals over 40. Even under regular screening, some are still diagnosed at advanced stages. We aimed to identify characteristics of interval gastric neoplasms (IGNs) with rapid progression.

Results

Newly-diagnosed gastric neoplasms detected in screening endoscopy between January 2004 and May 2016 were reviewed. Among them, those who had previous endoscopy within 2 years were enrolled. Endoscopic findings, family history of gastric cancer, smoking, and H. pylori status were analysed. Totally, 297 IGN cases were enrolled. Among them, 246 were endoscopically treatable IGN (ET-IGN) and 51 were endoscopically untreatable IGNs (EUT-IGN) by the expanded criteria for endoscopic submucosal dissection. Among EUT-IGNs, 78% were undifferentiated cancers (40/51) and 33% showed submucosal invasion (13/40). They were median 2.0 cm in size and more commonly located in the proximal stomach than ET-IGNs (70.6% vs. 41.9%, p < 0.001). EUT-IGN was independently related with age < 60 (OR, 2.09; 95%CI, 1.03–4.26, p = 0.042), H. pylori (OR, 2.81; 95%CI, 1.20–6.63, p = 0.018), and absent/mild gastric atrophy (OR, 2.67; 95%CI, 1.25–5.72, p = 0.011). Overall and disease-specific survival were not significantly different between the two groups, however EUT-IGN tended to have short disease-specific survival (overall survival, p = 0.143; disease-specific survival, p = 0.083).

Conclusions

Uniform screening endoscopy with two-year interval seems not enough for rapid-growing gastric neoplasms, such as undifferentiated cancers. They tended to develop in adults younger than 60 with H. pylori infection without severe gastric atrophy. More meticulous screening, especially for proximal lesions is warranted for adults younger than 60 with H. pylori infection before development of gastric atrophy.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12885-021-07929-y.

Robust closure of post-endoscopic submucosal dissection perforation by microparticle-based wound dressing

Endoscopic submucosal dissection (ESD) has been used as a minimally invasive cancer treatment for early-stage gastrointestinal cancer. However, cancer dissection in thin tissues, such as the duodenum and large intestine, often cause post-ESD and delayed perforation, which elicit severe complications. In this study, we report a microparticle-based wound dressing with hydrophobically-modified gelatin that can close the perforation after ESD. Hydrophobized microparticles were prepared using a coacervation method in a water/ethanol mixed solvent. The optimized alkyl chain length and degree of substitution of hydrophobic groups improved the mechanical strength of the hydrogel formed by hydration and fusion of the microparticles. The hydrogels formed on tissue defects revealed higher burst strength in ex vitro perforation models using duodenum, large intestine, and stomach under wet conditions compared with hydrogels without hydrophobic modification. The particle fusion was determined to be a crucial step to yield a high burst strength. An in vivo degradability evaluation showed that microparticle hydrogels subcutaneously implanted in rats degraded within 14 days. The microparticle wound dressing is expected to be applicable to post-ESD perforation and prevent delayed perforation.

The risk factors for prolonged hemostatic clip retention after endoscopic submucosal dissection for gastric neoplasm

BACKGROUND

Endoscopic hemostatic clipping is a safe and efficient treatment used to manage bleeding or perforation during endoscopic submucosal dissection (ESD) for gastric neoplasm. However, the natural history of applied hemoclips during ESD has not been elucidated. As prolonged clip retention limits the use of magnetic resonance imaging and may impede the ulcer healing process, we investigated the factors associated with prolonged hemoclip retention during gastric ESD.

METHODS

We retrospectively reviewed 199 patients who underwent gastric ESD with hemoclip application from January 2006 to January 2019. The primary outcome was the prolonged hemoclip retention rate 3 months after ESD. We examined the records of subjects followed at 3, 6, and 12 months and then annually after ESD to monitor clip retention.

RESULTS

The prolonged hemoclip retention rate at 3 months was 27.1% (54/199). The risk of hemoclip retention was significantly lower at the antrum (19.6%, P = 0.03). Hemoclips at the angle tended to remain longer than other locations in the stomach (40.6%, P = 0.081) while there was no difference in the number of applied clips depending upon the location of the lesion. By Kaplan-Meier survival analysis, clips at the antrum detached significantly earlier than those at other locations (P = 0.011).

CONCLUSIONS

Most of the hemostatic clips attached during ESD were spontaneously removed by 3 months after gastric ESD. However, clips positioned at angle are suspected to have a high probability of prolonged retention. With this in mind, more attention is needed when using hemoclips on angle.

Protective effect of proton pump inhibitors and potassium competitive acid blockers against post-gastric endoscopic submucosal dissection bleeding: a single-center, propensity score-matched analysis

OBJECTIVES

Both potassium-competitive acid blockers (P-CABs) and proton pump inhibitors (PPIs) are known to be protective against bleeding after gastric endoscopic dissection (ESD) for early gastric cancers. The aim was to compare the effect of PPI and P-CAB treatment against bleeding after gastric ESD.

MATERIALS AND METHODS

This was a single-center, retrospective analysis. Among 541 patients who underwent gastric ESD during the period from 2014 to 2019, we recruited subjects who were treated with PPIs (intravenous lansoprazole followed by oral esomeprazole) or a P-CAB before and after ESD. The incidence of post-ESD bleeding was compared between treatment groups. The risks associated with post-ESD bleeding were examined by univariate and multivariate analyses after propensity score-matching.

RESULTS

The overall incidence of post-ESD bleeding was not significantly different between patients treated with PPIs (n = 362) and those treated with a P-CAB (n = 156) (3.0% vs 2.6%, respectively; p = .77). Even after propensity score matching (n = 153 in each group), the incidence was not significantly different between groups (2.6% vs 2.6%, respectively; p = 1.00). A multivariate analysis revealed that antithrombotic therapy (OR 4.85, 95% CI 1.14-20.57) was an independent factor associated with post-ESD bleeding.

CONCLUSIONS

The incidence of post gastric ESD bleeding is not different between patients treated with PPI and patients treated with P-CAB. Antithrombotic therapy is an independent risk factor associated with post-ESD bleeding.

Clinico-pathologic determinants of non-e-curative outcome following en-bloc endoscopic submucosal dissection in patients with early gastric neoplasia

Background

Endoscopic submucosal dissection (ESD) is gaining enormous popularity in the treatment of early gastric cancers (EGCs) in many institutions across the world. However, appropriate selection of candidates for endoscopic resection is crucial to sufficiently mitigate non-e-curative (NEC) resection. This study aims at identifying the various clinico-pathologic factors that independently predict the NEC outcome and depth of submucosal invasion following ESD procedure in patients with EGC.

Methods

Multiple logistic regression analysis was applied to investigate factors that independently predict both non-curability phenomenon and the level of submucosal invasion in patients with early gastric neoplasia. Statistical Packages for the Social Sciences version 23 was used for analysis.

Results

A total of 153 patients (162 EGC lesions) underwent en-bloc ESD after which the rate of complete resection and non-e-curative outcome were 95% and 22.2%, correspondingly. Multivariate analysis depicted that tumor location in the upper two third of stomach (odds ratio [OR], 5.46; 95% confidence interval [95% CI], 1.65–18.12; p = 0.006), tumor size > 2 cm (OR, 7.63; 95% CI, 2.29–25.42; p = 0.001), histologically undifferentiated tumor (OR, 15.54; 95% CI, 1.65–146.22; p = 0.001), and tumors with 0-IIa/0-IIc or their mixed variants with predominant 0-IIa/0-IIc (OR, 9.77; 95% CI, 1.23–77.65; p = 0.031) were all independent predictors of NEC resection for early gastric tumors. Additionally, location in the upper two third of the stomach (OR, 8.88; 95% CI, 2.90–27.17; p < 0.001), ulcerated lesions (OR, 3.70; 95% CI, 1.15–11.90; p = 0.028), lesions with > 2 cm (OR, 2.94; 95% CI, 1.08–8.02; p = 0.036) and those with poor differentiation (OR, 6.51; 95% CI, 2.23–18.98; p = 0.001) were found to have significant association with submucosal invasion.

Conclusions

Tumors located in the upper two third of the stomach having a larger size (> 2 cm), poor histo-differentiation and a gross type of 0-IIa/0-IIc or their mixed variants with predominant 0-IIa/0-IIc were significantly associated with a risk of NEC after ESD procedure. Thus, early gastric tumors displaying these features need to be handled carefully during endoscopic resection. Our findings may shed light on the pre-procedural detection of clinicopathologic factors that determine non-e-curability in patients with EGC.

Skeletal Muscle Depletion: A Risk Factor for Pneumonia following Gastric Endoscopic Submucosal Dissection in Elderly Patients

INTRODUCTION

Endoscopic submucosal dissection (ESD) is an effective treatment for gastric neoplasms in elderly patients; however, it involves several adverse events, including pneumonia. This study aimed to investigate whether skeletal muscle depletion (SMD) was associated with the development of pneumonia in elderly patients who underwent gastric ESD.

METHODS

This retrospective observational cohort study included 157 patients (≥80 years) who had undergone gastric ESD. The skeletal muscle cross-sectional area was measured by CT, and the value of the third lumbar vertebra skeletal muscle index (L3 SMI) was evaluated. The SMD was defined as an L3 SMI value ≤38.0 cm2/m2 for women and ≤42.0 cm2/m2 for men. Pneumonia was also diagnosed using CT to identify all included patients.

RESULTS

Among 157 patients, 66 (42.0%) showed SMD. In the SMD group, the incidence of pneumonia was 21.2%, whereas it was 7.7% in the non-SMD group (p = 0.018). The longest hospitalization duration was 19 days. Antibiotics were administered in 61.9% of the patients. Procedure time was not significantly different between the groups (72 ± 54 min vs. 62 ± 44 min, p = 0.201). On multivariate analysis, SMD was an independent risk factor for the development of pneumonia (odds ratio = 3.16, 95% confidence interval, 1.18-8.50, p = 0.023).

CONCLUSIONS

SMD was not a rare entity in patients aged ≥80 years with gastric neoplasms. SMD was a significant risk factor for pneumonia related to gastric ESD in elderly patients.

The Significance of Exosomal RNAs in the Development, Diagnosis, and Treatment of Gastric Cancer

Gastric cancer (GC) is one of the most common malignancies in the world. Exosomes, a subset of extracellular vesicles with an average diameter of 100 nm, contain and transfer a variety of functional macromolecules such as proteins, lipids, and nucleic acids. A large number of studies indicated that exosomes can play a significant role in the initiation and development of GC via facilitating intercellular communication between gastric cancer cells and microenvironment. Exosomal RNAs, one of the key functional cargos, are involved in the pathogenesis, development, and metastasis of GC. In addition, recent studies elucidated that exosomal RNAs may serve as diagnostic and prognostic biomarkers or therapeutic targets for GC. In this review, we summarized the function of exosomal RNA in the tumorigenesis, progression, diagnosis, and treatment of GC, which may further unveil the functions of exosome and promote the potentially diagnostic and therapeutic application of exosomes in GC.

Guidelines for endoscopic submucosal dissection and endoscopic mucosal resection for early gastric cancer (second edition)

In response to the rapid and wide acceptance and use of endoscopic treatments for early gastric cancer, the Japan Gastroenterological Endoscopy Society, in collaboration with the Japanese Gastric Cancer Association, produced "Guidelines for Endoscopic Submucosal Dissection and Endoscopic Mucosal Resection for Early Gastric Cancer" in 2014, as a set of basic guidelines in accordance with the principles of evidence-based medicine. At the time, a number of statements had to be established by consensus (the lowest evidence level), as evidence levels remained low for many specific areas in this field. However, in recent years, the number of well-designed clinical studies has been increasing. Based on new findings, we have issued the revised second edition of the above guidelines that cover the present state of knowledge. These guidelines are divided into the following seven categories: indications, preoperative diagnosis, techniques, evaluation of curability, complications, long-term postoperative surveillance, and histology.

Do Protocadherins Show Prognostic Value in the Carcinogenesis of Human Malignant Neoplasms? Systematic Review and Meta-Analysis

Background:

Protocadherins (PCDHs) have been reported as tumor suppressor genes, implying that these genes may be involved in tumor suppression in a variety of cancers. However, a thorough understanding of the functions and mechanisms of PCDHs remains limited. Our aim was to investigate the methylation profile of PCDHs in human malignant neoplasms.

Methods:

This systematic review has been recorded in PROSPERO (#42019117844) and conducted according to PRISMA’s checklist; search was conducted in LILACS, PubMed, Science Direct, Scopus, and Web of Science databases, manually, with search queries and without date or language restrictions.

Results:

We found 91 articles, of which 26 were used for this meta-analysis and categorized according to the origin of the neoplasia. In total, 3,377 cases were compiled, with PCDH10, PCDH17, and PCDH8 being the most studied; males were 2.22 times more affected than females. Studies have shown significant heterogeneity (p <0.001), with the odds ratio varying between cases and controls [2.20 (95% CI = 1.11– 4.35) to 209.05 (95% CI = 12.64– 2,457.18)], and the value of association between methylation and cancers studied was 26.08 (95% CI = 15.42–44.13).

Conclusion:

In this systematic review, we have demonstrated using meta-analysis that PCDHs could emerge as potential tumor suppressor genes and that a significant increase in methylation may be useful for early detection of different cancers. This work may help in the identification of new prognostic biomarkers in malignant neoplasms.

Endoscopic Submucosal Dissection for Upper Gastrointestinal Neoplasia-a North American Perspective

OBJECTIVES

Organ-sparing endoscopic submucosal dissection (ESD) is an acceptable treatment strategy for superficial neoplastic lesions of the esophagus and stomach. The adoption of this technique has lagged in North America compared with Asia, and we sought to report on our experiences with ESD for upper GI neoplasia.

METHODS

A prospectively entered database of all patients undergoing endoscopic resection of esophageal and gastric neoplasia at McGill University from 2009 to 2019 was queried for those who received ESD.

RESULTS

A total of 103 consecutive ESDs were identified from 2009 to 2019. Seventy-one (69%) patients were male and the median age was 72 (range: 38-90). Sixty-one (59%) cases were esophageal and 42 (41%) gastric. Forty-nine (48%) were performed in the endoscopy suite under local sedation only. Perforation occurred in 9 patients (7 esophageal and 2 stomach), of which 3 required operative repair. Histology was principally invasive carcinoma (79, 77%), with 17 (16%) dysplastic lesions (e.g., HGD), 1 (1%) neuroendocrine tumor, and 7 (7%) benign lesions. En bloc resection was achieved in 90 (87%), and the complete resection rate was 74 (72%), with 51 (50%) of procedures fulfilling the criteria for curative resection. At medium of 23-month (2-199) follow-up of these 51 curative resections, one case of recurrent carcinoma was found at follow-up and was managed with repeat endoscopic resection. Non-curative ESDs were found 45 (R1 resection = 29: risk of lymph node metastasis = 16), 21 had active surveillance, and 24 were resected.

CONCLUSION

ESD is a viable, effective, and safe therapeutic and staging modality for superficial lesions of the stomach and esophagus.

Long-Term Outcomes and Prognostic Factors of Endoscopic Submucosal Dissection for Early Gastric Cancer in Patients Aged ≥75 Years

Simple Summary

The number of elderly patients with early gastric cancer (EGC) who meet the indications for endoscopic submucosal dissection (ESD) is increasing. Since elderly patients have more comorbidities, and lower life expectancy than younger patients, special considerations to establish treatment strategies according to prognosis is needed. We investigate overall survival and risk factors related to survival after ESD in these patients. During the follow-up, the 3-, 5-, and 10-year overall survival was 91.2%, 83.5%, and 54.5%, respectively. Smoking, history of cancer of other organs, neutrophil to lymphocyte ratio > 1.6, Charlson comorbidity index ≥ 3, and presence of lymphovascular invasion were independent five risk factors for poor overall survival. The long-term outcome of ESD was poorer in elderly patients with risk factors than in those without. These prognostic factors can also be useful in deciding whether to recommend additive surgery and a close follow-up after non-curative endoscopic treatment in the elderly patients.

Abstract

Background and Aims: The number of elderly patients with early gastric cancer (EGC) who meet the indications for endoscopic submucosal dissection (ESD) is increasing. We aimed to evaluate the clinical outcomes and prognostic factors of overall survival (OS) in elderly patients undergoing ESD for EGC. Methods: Between January 2006 and December 2018, 439 patients aged ≥75 years who underwent ESD for EGC were analyzed. The clinical outcomes and prognosis were evaluated, and independent risk factors for OS were identified. Results: The mean patient (302 men, 137 women) age was 78.3 (range 75–92) years. En bloc, R0, and curative resections were achieved in 96.8%, 90.7%, and 75.6%, respectively, without severe adverse events. During the follow-up (median 54.2 (range 4.0–159.6) months), 86 patients died (three of gastric cancer). The 3-, 5-, and 10-year OS was 91.2%, 83.5%, and 54.5%, respectively, and the 3-, 5-, and 10-year cancer related survival rate were 99.7%, 99.1% and 97.5%, respectively. In multivariate analysis, smoking, history of cancer of other organs, NLR > 1.6, Charlson comorbidity index ≥ 3, and presence of lymphovascular invasion (hazard ratio = 3.96, 1.78, 1.83, 1.83, and 2.63, respectively, all p < 0.05) were independent five risk factors for poor OS. The high-risk group (≥3 risk factors) showed a significantly lower OS than the low-risk group (<2 risk factors) (p < 0.001). Conclusions: The five factors could be useful in predicting the long-term prognosis of elderly ESD patients or deciding the therapeutic approaches in case of non-curative resection.

Computational Fluid Dynamics (CFD)-Based Optimization of Injection Process during Endoscopic Mucosal Therapy

Creation of a submucosal plane to separate the lesion from the deeper muscle layer in gastrointestinal tract is an integral and essential part of endoscopic resection therapies such as endoscopic mucosal resection (EMR) and endoscopic submucosal dissection (ESD). Thereby, an optimized submucosal injection technique is required to ensure a successful process. In this study, the computational fluid dynamics (CFD) technique is employed as a foundational step towards the development of a framework that can provide useful directions to optimize the injection process. Three different lifting agents, including Glycerol, Eleview^®, and ORISE^® gel have been used for this study. The role of different injection angles, injection dynamics, and effect of temperature are studied to understand the lifting characteristic of each agent. The study shows that Eleview^® provides the highest lifting effect, including the initial injection period. To evaluate the impact of the injection process, two cases are simulated, termed static injection and dynamic injection. Under static injection, the injection angle is investigated from lower to higher angles of injection. In the dynamic injection, two cases are modulated, where a continuous change of injection angle from lower to higher degrees (denoted as clockwise) and vice-versa in the anti-clockwise direction are investigated. Increased lifting characteristics are observed at decreasing/lower angle of injection. Further, the correlation between temperature of the lifting agents and their lifting characteristics is investigated.

A predictive signature for oxaliplatin and 5-fluorouracil based chemotherapy in locally advanced gastric cancer

Adjuvant chemotherapy(AC) plays a substantial role in the treatment of locally advanced gastric cancer (LAGC), but the response remains poor. We aims to improve its efficacy in LAGC. Therefore, we identified the expression of eight genes closely associated with platinum and fluorouracil metabolism (RRM1, RRM2, RRM2B, POLH, DUT, TYMS, TYMP, MKI67) in the discovery cohort (N=291). And we further validated the findings in TCGA (N=279) and GEO. Overall survival (OS) was used as an endpoint. Univariate and multivariate Cox models were applied. A multivariate Cox regression model was simulated to predict the OS. In the discovery cohort, the univariate Cox model indicated that AC was beneficial to high-RRM1, high-DUT, low-RRM2, low-RRM2B, low-POLH, low-KI67, low-TYMS or low-TYMP patients, the results were validated in the TCGA cohort. The multivariate Cox model showed consistent results. Cumulative analysis indicated that patients with low C-Score respond poorly to the AC, whereas the high and medium C-Score patients significantly benefit from AC. A risk model based on the above variables successfully predicted the OS in both cohorts (AUC=0.75 and 0.67, respectively). Further validation in a panel of gastric cancer cell (GC) lines (N=37) indicated that C-Score is significantly associated with IC50 value to fluorouracil. Mutation profiling showed that C-Score was associated with the number and types of mutations. In conclusion, we successfully simulated a predictive signature for the efficacy of AC in LAGC patients and further explored the potential mechanisms. Our findings could promote precision medicine and improve the prognosis of LAGC patients.

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We successfully simulated a predictive signature for the efficacy of chemotherapy in LAGC patients and a GC cell line panel.

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We further explored the potential mechanisms that it may be associated with the number and type of mutations.

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Our findings could promote precision medicine and improve the prognosis of LAGC patients.

The risks and characteristics of the delayed bleeding after endoscopic submucosal dissection for early gastric carcinoma in cases with anticoagulants

BACKGROUND

Endoscopic submucosal dissection (ESD) is a minimally invasive treatment for early gastric carcinoma. Vitamin K antagonists and direct oral anticoagulants (DOAC) were reported to increase the risk of delayed bleeding after ESD. However, the evaluation of ESD cases taking anticoagulants is scarce. We analyzed the risk and characteristics of delayed bleeding after gastric ESD in patients on anticoagulants.

METHODS

We performed a retrospective observational study at a single center. Consecutive patients who underwent ESD for early gastric carcinoma and took anticoagulants, including warfarin, rivaroxaban, dabigatran, apixaban, and edoxaban, between January 2012 and December 2018, were analyzed. We also calculated delayed bleeding rates for those without anticoagulants.

RESULTS

Of 1855 eligible patients who underwent gastric ESDs, 143 took anticoagulants. Delayed bleeding occurred in 30 (21.0%) cases taking anticoagulants, with 15 (19.5%) cases in the DOAC group [rivaroxaban, seven cases (21.2%); dabigatran, four cases (20.0%); apixaban, four cases (23.5%); and edoxaban, zero cases (0%)] and 15 cases (22.7%) in the warfarin group. Furthermore, 43/344 (12.5%) patients taking antiplatelets and 76/1368 (5.6%) patients without antithrombic drugs experienced delayed bleeding. Multivariable logistic analysis revealed post-heart valve replacement (OR, 6.56; 95% CI, 1.75-24.7; p < .05) as a risk for delayed bleeding in warfarin-taking patients, while no statistically significant factor was found in DOAC-taking patients.

CONCLUSIONS

Anticoagulants were associated with a high incidence of severe delayed bleeding. Careful attention should be paid to patients on anticoagulants after gastric ESD, especially those on warfarin after heart valve replacement.

Establishment of Decision Rules and Risk Assessment Model for Preoperative Prediction of Lymph Node Metastasis in Gastric Cancer

Background: Preoperative accurate prediction of lymph node status is especially important for the formulation of treatment plans for patients with gastric cancer (GC). The purpose of this study was to establish decision rules and a risk assessment model for lymph node metastasis (LNM) in GC using preoperative indicators. Methods: The clinical data of 554 patients who underwent gastrectomy with D2 lymphadenectomy were collected. A 1:1 propensity score matching (PSM) system was used, and the clinical data of the matched 466 patients were further analyzed. The important risk factors for LNM were extracted by the random forest algorithm, and decision rules and nomogram models for LNM were constructed with a classification tree and the "rms" package of R software, respectively. Results: Tumor size (OR: 2.058; P = 0.000), computed tomography (CT) findings (OR: 1.969; P = 0.001), grade (OR: 0.479; P = 0.000), hemoglobin (Hb) (OR: 1.211; P = 0.005), CEA (OR: 1.111; P = 0.017), and CA19-9 (OR: 1.040; P = 0.033) were independent risk factors for LNM in GC. Tumor size did rank first in the ranking of important factors for LNM in GC and was the first-level segmentation of the two initial branches of the classification tree. The accuracy, sensitivity, specificity, and positive predictive value of the decision rules in diagnosing preoperative LNM in GC were 75.6, 85.7, 73.9, 73.5, and 79.3%, respectively. The accuracy, sensitivity, and specificity of the risk assessment model in predicting preoperative LNM in GC were 79.3, 80.3, and 79.4%, respectively. Conclusion: Tumor size was the most important factor for evaluating LNM in GC. This decision rules and nomogram model constructed to take into account tumor size, CT findings, grade, hemoglobin, CEA, and CA19-9 effectively predicted the incidence of LNM in preoperative GC.

Helicobacter pylori Eradication Can Reverse the Methylation-Associated Regulation of miR-200a/b in Gastric Carcinogenesis

Background/Aims

Epigenetic change is one of the mechanisms that regulates the expression of microRNAs (miRNAs) and is known to play a role in Helicobacter pylori-associated gastric carcinogenesis. We aimed to evaluate the epigenetic changes of miR-200a/b in H. pylori-associated gastric carcinogenesis and restoration after eradication.

Methods

The expression and methylation levels of miR-200a/b were evaluated in gastric cancer (GC) cell lines, human gastric mucosa of H. pylori-negative and -positive controls, and H. pylori-positive GC patients. Next, the changes in the expression and methylation levels of miR-200a/b were compared between H. pylori-eradication and H. pylori-persistence groups at 6 months. Real-time reverse transcription-polymerase chain reaction was conducted to investigate the miRNA expression levels, and MethyLight was performed to assess the methylation levels.

Results

In the GC cell lines, the level of miR-200a/b methylation decreased and the level of expression increased after demethylation. In the human gastric mucosa, the miR-200a/b methylation levels increased in the following group order: H. pylori-negative control group, H. pylori-positive control group, and H. pylori-positive GC group. Conversely, the miR-200a/b expression levels decreased in the same order. In the H. pylori-persistence group, no significant changes were observed in the methylation and expression levels of miR-200a/b after 6 months, whereas the level of methylation decreased and the level of expression of miR-200a/b increased significantly 6 months in the H. pylori-eradication group.

Conclusions

Epigenetic alterations of miR-200a/b may be implicated in H. pylori-induced gastric carcinogenesis. This field defect for cancerization is suggested to be improved by H. pylori eradication.

Management following endoscopic resection in elderly patients with early-stage upper gastrointestinal neoplasia

With the ongoing increase in the aging population in Japan, the number of elderly patients among the total population with upper gastrointestinal (GI) neoplasia has also been increasing. As elderly patients present unique age-related variations in their physical condition, the therapeutic approach for upper GI neoplasia should be differentiated between elderly and nonelderly patients. According to the existing guidelines, additional treatment is the standard therapy in patients who undergo endoscopic resection (ER) with a possible risk of lymph node metastasis (LNM) for upper GI neoplasia. However, due to the relatively low rate of LNM, applying additional treatment in all elderly patients may be excessive. Although additional treatment has the advantage of reducing cancer-specific mortality, its disadvantages include deteriorated quality of life, complications, and mortality in surgery. In patients with early gastric cancer, we propose treatment decisions be made using a risk-scoring system for LNM and upon considering the physical condition of the patient after ER with curability C-2. In those with superficial esophageal squamous cell carcinoma with a possible risk of LNM after ER, selective chemoradiotherapy may be a less-invasive treatment option, although the present standard treatment is esophagectomy. When considering the treatment decision, achieving a "cure" of the tumor has been regarded as critical. However, as the main cause of mortality in elderly patients with ER for upper GI neoplasia is noncancer-related death, both achieving a "cure" and also a good level of "care" is important in the management of elderly patients.

A deep learning method for delineating early gastric cancer resection margin under chromoendoscopy and white light endoscopy

BACKGROUND

Accurate delineation of cancer margins is critical for endoscopic curative resection. This study aimed to train and validate real-time fully convolutional networks for delineating the resection margin of early gastric cancer (EGC) under indigo carmine chromoendoscopy (CE) or white light endoscopy (WLE), and evaluated its performance and that of magnifying endoscopy with narrow-band imaging (ME-NBI).

METHODS

We collected CE and WLE images of EGC lesions to train fully convolutional networks ENDOANGEL. ENDOANGEL was tested both on stationary images and endoscopic submucosal dissection (ESD) videos. The accuracy and reliability of ENDOANGEL and NBI-dependent delineation were further evaluated by a novel endoscopy-pathology point-to-point marking.

RESULTS

ENDOANGEL had an accuracy of 85.7% in the CE images and 88.9% in the WLE images under an overlap ratio threshold of 0.60 in comparison with the manual markers labeled by the experts. In the ESD videos, the resection margins predicted by ENDOANGEL covered all areas of high-grade intraepithelial neoplasia and cancers. The minimum distance between the margins predicted by ENDOANGEL and the histological cancer boundary was 3.44 ± 1.45 mm which outperformed the resection margin based on ME-NBI.

CONCLUSIONS

ENDOANGEL has the potential to assist endoscopists in delineating the resection extent of EGC under CE or WLE during ESD.

Influence of Tumor Location on Lymph Node Metastasis and Survival for Early Gastric Cancer: a Population-Based Study

BACKGROUND

The question that whether the criteria for endoscopic resection of early gastric non-cardia cancer (GNCC) is appropriate for early gastric cardia cancer (GCC) remains unclear. Thus, our aim was to evaluate the influence of tumor location on lymph node metastasis (LNM) and overall survival (OS) for early gastric cancer (GC).

METHODS

A total of 5440 early GC patients in the Surveillance, Epidemiology, and End Results (SEER) database were identified. Multivariable analysis was performed to evaluate the influence of tumor location on LNM and OS for early GC.

RESULTS

The rate of LNM was 17.48% for early GCC patients (232/1327) and 18.62% for early GNCC patients (766/4113). The early GCC patients experienced no significantly different risk of LNM compared with the early GNCC patients (adjusted OR 0.92, 95% CI 0.76-1.12, P = 0.405). The early GC patients were further stratified by node status. Tumor location was not a predictor of OS for node-negative early GC patients (adjusted HR 1.07, 95% CI 0.96-1.21, P = 0.225) but a predictor of OS for node-positive early GC patients (adjusted HR 1.80, 95% CI 1.48-2.20, P < 0.001).

CONCLUSIONS

Tumor location was not a predictor of LNM for early GC patients. Moreover, tumor location was not a predictor of OS for node-negative early GC patients. Thus, the criteria for endoscopic resection of early GNCC might be appropriate for the treatment of early GCC.

Usefulness of the flexible traction method in gastric endoscopic submucosal dissection: an in-vivo animal study

BACKGROUND

An appropriate traction of the target lesion is a key for a safe and secure ESD procedure. We proposed the flexible traction method (F-trac) which provided an optimal traction using an endoscopic hand-suturing (EHS) and investigated the usefulness of this technique for gastric ESD in-vivo porcine model.

METHODS

In the F-trac method, a lesion was suspended by pulling proximal side of endoscope which was connected to the contralateral side with a barbed suture using the EHS technique just before starting the submucosal dissection. A single endoscopist performed conventional ESD (C-ESD) and F-trac ESD alternately for a total of ten simulating lesions of 3 cm in diameter in a live porcine stomach. The pig was rotated so that each lesion was positioned in the direction of the gravity. The procedure time, technical accuracy, adverse events, and the number of additional injection to the submucosal layer during dissection were evaluated.

RESULTS

The total ESD procedure time in the F-trac group was significantly shorter than in C-ESD group (19.0 min vs. 30.6 min, p = 0.039). There were no significant differences between both groups in muscular layer damage, sample damage, perforation, and intraoperative bleeding. The number of additional injection in the F-trac group was significantly fewer than that in C-ESD group (0 times vs. 4.4 times, p = 0.027).

CONCLUSIONS

In gastric ESD, F-trac might be useful for shortening the total procedure time. This method can facilitate optimal traction without disturbing the endoscopic visualization and the movement of endoscope.