Endoscopic submucosal dissection of early gastric cancer

A risk prediction model for delayed bleeding after ESD for gastric precancerous lesions

OBJECTIVE

To investigate the risk factors for delayed postoperative bleeding after endoscopic submucosal dissection (ESD) in patients with gastric precancerous lesions and to construct a risk prediction model.

METHODS

This retrospective analysis included clinical data from patients with gastric precancerous lesions who underwent ESD at Wuhan University People's Hospital between November 2016 and June 2022. An XGBoost model was built to predict delayed bleeding after ESD using risk factors identified by univariable and multivariate logistic regression analysis. The model was evaluated using receiver operating characteristic curves (ROC), and SHapely Additive exPlanations (SHAP) analysis was used to interpret the model.

RESULTS

Seven factors were statistically associated with delayed postoperative bleeding in gastric precancerous lesions after ESD: age, low-grade intraepithelial neoplasia, hypertension, lesion size ≥ 40 mm, operative time ≥ 120 min, female, and nonuse of hemoclips. A risk prediction model was established. In the training cohort, the model achieved an AUC of 0.97 (0.96-0.98), a sensitivity of 0.90, a specificity of 0.94, and an F1 score of 0.91. In the validation cohort, the AUC was 0.94(0.90-0.98), with a sensitivity of 0.85, a specificity of 0.89, and an F1 score of 0.85. In the test cohort, the AUC was 0.94 (0.89-0.99), the sensitivity was 0.80, the specificity was 0.92, and the F1 score was 0.84, indicating strong predictive capability.

CONCLUSION

In this study, an XGBoost prediction model for assessing the risk of delayed postoperative bleeding after ESD in patients with gastric precancerous lesions was developed and validated. This model can be applied in clinical practice to effectively predict the risk of post-ESD bleeding for individual patients.

Development of a novel multipoint traction device for gastric and colorectal endoscopic submucosal dissection and evaluation of its efficacy and safety

BACKGROUND

Proper traction allows safer and easier endoscopic submucosal dissection; however, single-point traction may not be sufficient. In this study we assessed the safety, efficacy, and feasibility of our newly developed multipoint traction device.

METHODS

During an ex vivo study using a Konjac training model, two experts and two trainees resected 80 mock lesions of 20-mm diameter by performing endoscopic submucosal dissection with and without multipoint traction. The primary outcome was the success rate of the procedure involving traction. The secondary outcomes were the submucosal dissection time, dissection speed, and perforation during endoscopic submucosal dissection. During the in vivo study, to clarify the initial clinical outcomes, we used data from the electronic medical record of patients at our institution who underwent gastric and colorectal endoscopic submucosal dissection, which was performed by experts with our newly developed multipoint traction device, from March to December 2022.

RESULTS

The ex vivo study indicated that all traction procedures were successful. Higher resection speeds were observed with endoscopic submucosal dissection with traction than without traction (P < 0.001). Perforations were not observed. During the first in vivo clinical study, traction was feasible during 20 gastric and colorectal endoscopic submucosal dissection procedures. No adverse events occurred.

CONCLUSIONS

Our multitraction device can increase the submucosal dissection speed and simplify endoscopic submucosal dissection techniques, thus safely reducing technical challenges. The application of this device for endoscopic submucosal dissection could lead to safer and more efficient procedures. Clinical registration UMIN Clinical Trials Registry, Japan (registration number UMIN000053384).

Long-term outcomes of endoscopic submucosal dissection for undifferentiated type early gastric cancer over 2 cm with R0 resection

BACKGROUND

Endoscopic submucosal dissection (ESD) for over 2 cm in size undifferentiated type (UD type) early gastric cancer (EGC) confined to the mucosa is not only challenging, but also long-term outcomes are not well known.

AIM

To evaluate the long-term outcomes of ESD done for UD type EGCs confined to the mucosa over 2 cm in size and compare the results with those where the lesions were less than 2 cm.

METHODS

143 patients with UD type EGC confirmed on histology after ESD at a tertiary hospital were reviewed. Cases with synchronous and metachronous lesions and a case with emergency surgery after ESD were excluded. A total of 137 cases were enrolled. 79 cases who underwent R0 resection were divided into 2 cm or less (group A) and over 2 cm (group B) in size.

RESULTS

Among 79 patients who underwent R0 resection, the number in group A and B were 51 and 28, respectively. The mean follow-up period (SD) was 79.71 ± 45.42 months. There was a local recurrence in group A (1/51, 2%) and group B (1/28, 3.6%) respectively. This patient in group A underwent surgery while the patient in group B underwent repeated ESD with no further recurrences in both patients. There was no regional lymph node metastasis, distant metastasis, and deaths in both groups. With R0 resection strategy for ESD on lesions over 2 cm, 20.4% (28/137) of patients were able to avoid surgery compared with expanded indication.

CONCLUSION

If R0 resection is achieved by ESD, UD type EGCs over 2 cm also showed good and similar clinical outcomes as compared to lesions less than 2 cm when followed for over 5 years. With R0 resection strategy, several patients can avoid surgery.

Novel gastric endoscopic submucosal dissection training model enhances the endoscopic submucosal dissection skills of trainees: a multicenter comparative study

BACKGROUND

Endoscopic submucosal dissection (ESD) requires high endoscopic technical skills, and trainees should develop effective training methods. In collaboration with KOTOBUKI Medical, we developed the G-Master, which is a non-animal training model that can simulate various parts of gastric ESD. We aimed to clarify the usefulness of the G-Master for inexperienced ESD trainees.

METHODS

We collected data from the first 5 gastric ESD cases conducted by 15 inexperienced ESD trainees at 5 participating centers between 2018 and 2022. The participants were divided into two groups: the G-Master training and non-G-Master training groups. Outcome measurements, such as procedural speed, perforation rate, self-completion rate, and en bloc resection rate, were compared between the two groups retrospectively.

RESULTS

A total of 75 gastric ESD cases were included in this study. The G-Master training group included 25 cases performed by 5 trainees, whereas the non-G-Master training group included 50 cases performed by 10 trainees. The median procedural speed for all cases was significantly faster in the G-Master training group than in the non-G-Master training group. Moreover, the procedural speed was linearly improved from the initial to the last cases in the lower location in the G-Master training group compared with the non-G-Master training group. In addition, although there was no significant difference, the G-Master training group showed lower rates of perforation and a lesser need to transition to expert operators than the non-G-Master training group.

CONCLUSION

The G-Master could improve the ESD skills of inexperienced ESD trainees.

Association of direct oral anticoagulant and delayed bleeding with pharmacokinetics after endoscopic submucosal dissection

BACKGROUND AND AIMS

Pharmacokinetic parameters, such as drug plasma level at trough, time to maximum plasma concentration (Tmax), and coagulation factor Xa (FXa) activity generally predict factors for the anticoagulant effects of direct oral anticoagulants (DOACs). Although GI bleeding is a major adverse event after endoscopic submucosal dissection (ESD), little is known about the association between post-ESD bleeding in patients taking DOACs and the pharmacologic parameters. This study aimed to evaluate pharmacologic risk factors for post-ESD bleeding in patients taking DOACs.

METHODS

We prospectively evaluated the incidence of post-ESD bleeding in patients taking DOACs between April 2018 and May 2022 at 21 Japanese institutions and investigated the association with post-ESD bleeding and pharmacologic factors, including plasma concentration and FXa activity at trough and Tmax.

RESULTS

The incidence of post-ESD bleeding was 12.8% (14 of 109; 95% confidence interval [CI], 7.2-20.6). Although plasma DOAC concentration and plasma level/dose ratio at trough and Tmax varied widely among individuals, a significant correlation with plasma concentration and FXa activity was observed (apixaban: correlation coefficient, -0.893; P < .001). On multivariate analysis, risk factors for post-ESD bleeding in patients taking DOACs were higher age (odds ratio [OR], 1.192; 95% CI, 1.020-1.392; P = .027) and high anticoagulant ability analyzed by FXa activity at trough and Tmax (OR, 6.056; 95% CI, 1.094-33.529; P = .039).

CONCLUSIONS

The incidence of post-ESD bleeding in patients taking DOACs was high, especially in older patients and with high anticoagulant effects of DOACs. Measurement of pharmacokinetic parameters of DOACs may be useful in identifying patients at higher risk of post-ESD bleeding.

BFE-Net: bilateral fusion enhanced network for gastrointestinal polyp segmentation

Accurate segmentation of polyp regions in gastrointestinal endoscopic images is pivotal for diagnosis and treatment. Despite advancements, challenges persist, like accurately segmenting small polyps and maintaining accuracy when polyps resemble surrounding tissues. Recent studies show the effectiveness of the pyramid vision transformer (PVT) in capturing global context, yet it may lack detailed information. Conversely, U-Net excels in semantic extraction. Hence, we propose the bilateral fusion enhanced network (BFE-Net) to address these challenges. Our model integrates U-Net and PVT features via a deep feature enhancement fusion module (FEF) and attention decoder module (AD). Experimental results demonstrate significant improvements, validating our model's effectiveness across various datasets and modalities, promising advancements in gastrointestinal polyp diagnosis and treatment.

Comparison of vonoprazan and proton pump inhibitors for the treatment of gastric endoscopic submucosal dissection-induced ulcer: an updated systematic review and meta-analysis

BACKGROUND

Both vonoprazan and proton pump inhibitors (PPIs) are currently used to treat artificial ulcers after gastric endoscopic submucosal dissection. However, evidence-based medicine proving the efficacy of vonoprazan is still lacking. Therefore, this meta-analysis aimed to compare the efficacy of vonoprazan and PPIs for the treatment of artificial ulcers after gastric endoscopic submucosal dissection.

METHODS

The PubMed, EMBASE and Cochrane Library databases were searched up to September 2023 for related randomized controlled trials (RCTs). RCTs that compared the efficacy of vonoprazan and PPIs in treating artificial gastric ulcers after gastric endoscopic submucosal dissection were included. Two independent reviewers screened the included studies, extracted the data and assessed the risk of bias. The following outcomes were extracted for comparison: ulcer healing rate, ulcer shrinkage rate, delayed postoperative bleeding rate, and ulcer perforation rate.

RESULTS

Nine randomized controlled trials involving 926 patients were included. The pooled results showed that vonoprazan had a significantly lower rate of delayed postoperative bleeding than did PPIs (RR = 0.46; 95% CI = 0.23-0.91; P = 0.03). No significant differences were found in terms of ulcer healing, shrinkage rates, or ulcer perforation rates between vonoprazan and PPIs.

CONCLUSIONS

Compared with PPIs, vonoprazan is superior at reducing delayed postoperative bleeding after endoscopic submucosal dissection. However, further studies are needed to prove the efficacy of vonoprazan.

SYSTEMATIC REVIEW REGISTRATION

Identifier CRD42024509227.

Conventional Versus Traction-Assisted Endoscopic Submucosal Dissection for Esophageal, Gastric, and Colorectal Neoplasms: A Systematic Review and Meta-Analysis of Randomized Controlled Trials

Endoscopic submucosal dissection (ESD) is increasingly being utilized for the resection of superficial gastrointestinal neoplasms. However, the long procedure time poses a technical challenge for conventional ESD (C-ESD). Traction-assisted ESD (T-ESD) was developed to facilitate the procedure by reducing its duration. This study compares the efficacy and safety of C-ESD versus T-ESD in the treatment of esophageal, gastric, and colorectal neoplasms. Nine randomized controlled trials (RCTs) were analyzed. Traction-assisted ESD exhibited shorter mean dissection times for the esophagus and colorectal regions and lower perforation rates in colorectal cases. No significant differences were observed in en bloc resection or bleeding rates. Traction-assisted ESD proves to be more efficient in mean procedure time for esophageal and colorectal cases and safer in perforation rates for colorectal cases, but similar rates are noted for en bloc resection or bleeding.

Clinical Impact of Proton Pump Inhibitor and Potassium-Competitive Acid Blocker for Predicting the Curability of Endoscopic Resection in Ulcerative Early Gastric Cancer

INTRODUCTION

Endoscopic diagnosis is essential for predicting the curability of early gastric cancer (EGC; R0 resection) before treatment, but the relationship between ulcerative lesions and clinical outcomes remains unclear. We aimed to investigate the effect of proton pump inhibitor (PPI) or potassium-competitive acid blocker (P-CAB) on the morphological changes of ulcerative EGCs and its relevance to the clinical outcomes.

METHODS

Altogether, 143 patients with differentiated ulcerative EGC that were resected by endoscopic submucosal dissection were retrospectively identified and divided into the following two cohorts depending on their PPI/P-CAB administration status: PPI/P-CAB (n = 76) and non-PPI/P-CAB (n = 67) cohorts. Furthermore, in each cohort, the patients were further divided into the improved and unimproved subgroups based on the ulcerative changes.

RESULTS

In the PPI/P-CAB cohort, the deep submucosal invasion and lymphovascular invasion rates were significantly higher in the unimproved subgroup than in the improved subgroup, resulting in a significantly lower R0 resection rate. Contrarily, no significant differences were found between the two subgroups in the non-PPI/P-CAB cohort. The significance of PPI/P-CAB administration was observed only in the ulcerative EGCs with open-type atrophy (R0 resection rate; improved vs. unimproved, 90.9% vs. 48.0%, p = 0.001). When the finding of improved ulcer with PPI/P-CAB administration was used as the indication of endoscopic resection in ulcerative EGCs with open-type atrophy, high sensitivity (78.9%) and accuracy (76.3%) rates for the curability were observed, which were higher than those of conventional endoscopic diagnosis alone (p = 0.021).

CONCLUSION

PPI or P-CAB administration might contribute to the potential selection of ulcerative EGCs, enabling endoscopic curative resection.

The efficacy of newly proposed gastric open peroral endoscopic myotomy (GO-POEM) in preventing post-endoscopic submucosal dissection stenosis: A comparison with non-GO-POEM group

Extensive endoscopic submucosal dissection (ESD) for gastric adenoma or early cancer can lead to post-ESD stenosis. This may cause a decrease in quality of life and an increase in medical issues. Therefore, this study examined the safety and effectiveness of gastric open peroral endoscopic myotomy (GO-POEM) in preventing stenosis following ESD. A retrospective investigation was carried out on 31 patients who underwent gastric ESD for > 75% of the lumen in the antrum or pylorus at the Presbyterian Medical Center in Korea between December 2004 and October 2022. The patients were divided into GO-POEM (n = 11) and non-GO-POEM groups (n = 20). The average age of the 31 patients was 73.23 years, and 18 were male. There were no differences in age, sex, location, gross findings, or procedure time between the 2 groups. In the GO-POEM group, only 1 patient (9 %) developed stenosis, compared to 11 patients (55 %) in the control group (P = .02). Multivariate analysis showed that the GO-POEM group had a significantly lower risk of post-ESD stenosis (P < .05). Stenosis symptoms resolved with a single endoscopic balloon dilatation (EBD) in 1 patient in the GO-POEM group. In contrast, 5 of 11 patients with stenosis in the non-GO-POEM group required a median of 2 EBD sessions (range, 1-8). GO-POEM may be an effective and reliable method for preventing stenosis post extensive gastric ESD. Further investigations are necessary to establish its efficacy and safety.

Indications for Dental Floss Clip Traction During Gastric Endoscopic Submucosal Dissection by Less-Experienced Endoscopists

PURPOSE

Dental floss clip (DFC) traction-assisted endoscopic submucosal dissection (ESD) is widely performed owing to its simplicity. This study aimed to clarify the appropriate indications for the DFC traction method in early gastric cancer when ESD is performed by less-experienced endoscopists.

METHODS AND METHODS

We retrospectively analyzed 1,014 consecutive patients who had undergone gastric ESD performed by less-experienced endoscopists between January 2015 and December 2020. Gastric ESD was performed without DFC in all cases before December 2017 [DFC (-) group, 376 cases], and ESD was performed with DFC in all cases after January 2018 [DFC (+) group, 436 cases]. The procedure time and rates of en bloc resection, complete resection, and adverse events of the groups were compared.

RESULTS

The procedure time did not differ significantly between the 2 groups. However, when comparing lesions >20 mm, the procedure time in the DFC (+) group was significantly shorter than that in the DFC (-) group (95±46 vs. 75±31, P<0.01). The procedure time for lesions located in the greater curvature of the upper or middle stomach and lesions >20 mm located in the lesser curvature side of the stomach in the DFC (+) group was significantly shorter than that in the DFC (-) group.

CONCLUSIONS

The indications for DFC during gastric ESD by less-experienced endoscopists include lesions located in the greater curvature of the upper or middle stomach, and lesions >20 mm located in the lesser curvature of the stomach.

Usefulness of a new polyvinyl alcohol hydrogel (PVA-H)-based simulator for endoscopic submucosal dissection training: a pilot study

BACKGROUND/AIMS

We developed a new endoscopic submucosal dissection (ESD) simulator and evaluated its efficacy and realism for use training endoscopists.

METHODS

An ESD simulator was constructed using polyvinyl alcohol hydrogel sheets and compared to a previous ESD simulator. Between March 1, 2020, and December 30, 2021, eight expert endoscopists from three different centers analyzed the procedure-related factors of the simulator. Five trainees performed gastric ESD exercises under the guidance of these experts.

RESULTS

Although the two ESD simulators provided overall favorable outcomes in terms of ESD-related factors, the new simulator had several benefits, including better marking of the target lesion's limits (p<0.001) and overall handling (p<0.001). Trainees tested the usefulness of the new ESD simulator. The complete resection rate improved after 3 ESD training sessions (9 procedures), and the perforation rate decreased after 4 sessions (12 procedures).

CONCLUSION

We have developed a new ESD simulator that can help beginners achieve a high level of technical experience before performing real-time ESD procedures in patients.

Diagnostic accuracy of frozen section biopsy for early gastric cancer extent during endoscopic submucosal dissection: a prospective study

BACKGROUND

Accurate diagnosis of the lateral extent of early gastric cancer during endoscopic submucosal dissection (ESD) is crucial to achieve negative resection margins. Similar to intraoperative consultation with a frozen section in surgery, rapid frozen section diagnosis with endoscopic forceps biopsy may be useful in assessing tumor margins during ESD. This study aimed to evaluate the diagnostic accuracy of frozen section biopsy.

METHODS

We prospectively enrolled 32 patients undergoing ESD for early gastric cancer. Biopsy samples for the frozen sections were randomly collected from fresh resected ESD specimens before formalin fixation. Two different pathologists independently diagnosed 130 frozen sections as "neoplasia," "negative for neoplasia," or "indefinite for neoplasia," and the frozen section diagnosis was compared with the final pathological results of the ESD specimens.

RESULTS

Among the 130 frozen sections, 35 were from cancerous areas, and 95 were from non-cancerous areas. The diagnostic accuracies of the frozen section biopsies by the two pathologists were 98.5 and 94.6%, respectively. Cohen's kappa coefficient of diagnoses by the two pathologists was 0.851 (95% confidence interval: 0.837-0.864). Incorrect diagnoses resulted from freezing artifacts, a small volume of tissue, inflammation, the presence of well-differentiated adenocarcinoma with mild nuclear atypia, and/or tissue damage during ESD.

CONCLUSIONS

Pathological diagnosis of frozen section biopsy is reliable and can be applied as a rapid frozen section diagnosis for evaluating the lateral margins of early gastric cancer during ESD.

Multi-Scale Hybrid Vision Transformer for Learning Gastric Histology: AI-Based Decision Support System for Gastric Cancer Treatment

Gastric endoscopic screening is an effective way to decide appropriate gastric cancer treatment at an early stage, reducing gastric cancer-associated mortality rate. Although artificial intelligence has brought a great promise to assist pathologist to screen digitalized endoscopic biopsies, existing artificial intelligence systems are limited to be utilized in planning gastric cancer treatment. We propose a practical artificial intelligence-based decision support system that enables five subclassifications of gastric cancer pathology, which can be directly matched to general gastric cancer treatment guidance. The proposed framework is designed to efficiently differentiate multi-classes of gastric cancer through multiscale self-attention mechanism using 2-stage hybrid vision transformer networks, by mimicking the way how human pathologists understand histology. The proposed system demonstrates its reliable diagnostic performance by achieving class-average sensitivity of above 0.85 for multicentric cohort tests. Moreover, the proposed system demonstrates its great generalization capability on gastrointestinal track organ cancer by achieving the best class-average sensitivity among contemporary networks. Furthermore, in the observational study, artificial intelligence-assisted pathologists show significantly improved diagnostic sensitivity within saved screening time compared to human pathologists. Our results demonstrate that the proposed artificial intelligence system has a great potential for providing presumptive pathologic opinion and supporting decision of appropriate gastric cancer treatment in practical clinical settings.

Computer-aided demarcation of early gastric cancer: a pilot comparative study with endoscopists

BACKGROUND

Precise area diagnosis of early gastric cancer (EGC) is critical for reliable endoscopic resection. Computer-aided diagnosis (CAD) shows strong potential for detecting EGC and reducing cancer-care disparities caused by differences in endoscopists' skills. To be used in clinical practice, CAD should enable both the detection and the demarcation of lesions. This study proposes a scheme for the detection and delineation of EGC under white-light endoscopy and validates its performance using 1-year consecutive cases.

METHODS

Only 300 endoscopic images randomly selected from 68 consecutive cases were used for training a convolutional neural network. All cases were treated with endoscopic submucosal dissection, enabling the accumulation of a training dataset in which the extent of lesions was precisely determined. For validation, 462 cancer images and 396 normal images from 137 consecutive cases were used. From the validation results, 38 randomly selected images were compared with those delineated by six endoscopists.

RESULTS

Successful detections of EGC in 387 cancer images (83.8%) and the absence of lesions in 307 normal images (77.5%) were achieved. Positive and negative predictive values were 81.3% and 80.4%, respectively. Successful detection was achieved in 130 cases (94.9%). We achieved precise demarcation of EGC with a mean intersection over union of 66.5%, showing the extent of lesions with a smooth boundary; the results were comparable to those achieved by specialists.

CONCLUSIONS

Our scheme, validated using 1-year consecutive cases, shows potential for demarcating EGC. Its performance matched that of specialists; it might therefore be suitable for clinical use in the future.

Prediction of lymph node metastasis in early gastric signet-ring cell carcinoma: A real-world retrospective cohort study

BACKGROUND

Signet-ring cell carcinoma (SRCC) was previously thought to have a worse prognosis than other differentiated gastric cancer (GC), however, recent studies have shown that the prognosis of SRCC is related to pathological type. We hypothesize that patients with SRCC and with different SRCC pathological components have different probability of lymph node metastasis (LNM).

AIM

To establish models to predict LNM in early GC (EGC), including early gastric SRCC.

METHODS

Clinical data from EGC patients who had undergone gastrectomy at the First Affiliated Hospital of Nanjing Medical University from January 2012 to March 2022 were reviewed. The patients were divided into three groups based on type: Pure SRCC, mixed SRCC, and non-signet ring cell carcinoma (NSRC). The risk factors were identified through statistical tests using SPSS 23.0, R, and Em-powerStats software.

RESULTS

A total of 1922 subjects with EGC were enrolled in this study, and included 249 SRCC patients and 1673 NSRC patients, while 278 of the patients (14.46%) presented with LNM. Multivariable analysis showed that gender, tumor size, depth of invasion, lymphovascular invasion, ulceration, and histological subtype were independent risk factors for LNM in EGC. Establishment and analysis using prediction models of EGC showed that the artificial neural network model was better than the logistic regression model in terms of sensitivity and accuracy (98.0% vs 58.1%, P = 0.034; 88.4% vs 86.8%, P < 0.001, respectively). Among the 249 SRCC patients, LNM was more common in mixed (35.06%) rather than in pure SRCC (8.42%, P < 0.001). The area under the ROC curve of the logistic regression model for LNM in SRCC was 0.760 (95%CI: 0.682-0.843), while the area under the operating characteristic curve of the internal validation set was 0.734 (95%CI: 0.643-0.826). The subgroups analysis of pure types showed that LNM was more common in patients with a tumor size > 2 cm (OR = 5.422, P = 0.038).

CONCLUSION

A validated prediction model was developed to recognize the risk of LNM in EGC and early gastric SRCC, which can aid in pre-surgical decision making of the best method of treatment for patients.

Red dichromatic imaging improves visibility of bleeding during gastric endoscopic submucosal dissection

Bleeding frequently occurs during gastric endoscopic submucosal dissection (ESD) and bleeding points are sometimes difficult to detect. Red dichromatic imaging (RDI) was recently developed to improve the visibility of bleeding. Our study aimed at examining the efficacy of RDI in improving the visibility of bleeding during gastric ESD. We retrospectively evaluated the visibility score and color difference of bleeding spot during gastric ESD during September 2020-January 2021. The visibility score was evaluated as four numeric values by operators, and the color difference between the bleeding spot and surroundings was evaluated using RDI and white light imaging (WLI). A further analysis to evaluate bleeding characteristics was performed to evaluate the possible beneficial effects of RDI. Twenty patients with a total of 85 bleedings were analyzed. The mean visibility score in RDI was significantly higher than that in WLI (3.69 ± 0.60 vs 3.20 ± 0.84, p < 0.01). The color difference with RDI was also significantly higher than that with WLI (19.51 ± 15.18 vs 14.80 ± 7.41, p < 0.01). Furthermore, in the bleedings with a higher visibility score in RDI, the color difference in RDI was significantly higher than that in WLI (23.99 ± 19.29 vs 14.33 ± 7.08, p < 0.01). The multivariate analysis of visibility scores revealed that submergence of bleeding points was independently associated with the superiority of RDI (odds ratio 10.35, 95% confidence interval: 2.76-38.81, p < 0.01). Our study demonstrates that RDI can improve the visibility of bleeding during gastric ESD.

Assessment of delayed bleeding after endoscopic submucosal dissection of early-stage gastrointestinal tumors in patients receiving direct oral anticoagulants

Delayed bleeding is a major and serious adverse event of endoscopic submucosal dissection (ESD) for early-stage gastrointestinal tumors. The rate of post-ESD bleeding for gastric cancer is higher (around 5%-8%) than that for esophagus, duodenum and colon cancer (around 2%-4%). Although investigations into the risk factors for post-ESD bleeding have identified several procedure-, lesion-, physician- and patient-related factors, use of antithrombotic drugs, especially anticoagulants [direct oral anticoagulants (DOACs) and warfarin], is thought to be the biggest risk factor for post-ESD bleeding. In fact, the post-ESD bleeding rate in patients receiving DOACs is 8.7%-20.8%, which is higher than that in patients not receiving anticoagulants. However, because clinical guidelines for management of ESD in patients receiving DOACs differ among countries, it is necessary for endoscopists to identify ways to prevent post-ESD delayed bleeding in clinical practice. Given that the pharmacokinetics (e.g., plasma DOAC level at both trough and T_max) and pharmacodynamics (e.g., anti-factor Xa activity) of DOACs are related to risk of major bleeding, plasma DOAC level and anti-FXa activity may be useful parameters for monitoring the anti-coagulate effect and identifying DOAC patients at higher risk of post-ESD bleeding.

Comparison of the clinical and prognosis risk factors between endoscopic resection and radical gastrectomy for early-stage gastric cancer

AIM

This study aimed to explore the efficacy and safety of endoscopic submucosal dissection/endoscopic mucosal resection (ESD/EMR), laparoscopic-assisted radical gastrectomy (LARG), and open radical gastrectomy (ORG) in early-stage gastric cancer.

METHODS

A total of 417 patients with early-stage gastric cancer who were admitted in two hospitals from January 1, 2014 to July 31, 2017 were selected; the patients were divided into the ESD/EMR group (139 cases), LARG group (108 cases), and ORG group (170 cases) according to the operation methods used. The baseline data, economic cost of health, oncologic characteristics, postoperative complications, 5-year overall survival and disease-free survival, and risk factors of death were compared and analyzed.

RESULTS

No significant difference was observed in the baseline data among the three patient groups (P > 0.05). The total hospitalization days, operation time, postoperative fluid intake time, hospitalization expenses, and proportion of antibiotic use rate in the ESD/EMR group were lesser than those in other groups (P < 0.05). The LARG group has a longer operation time and higher hospitalization expenses compared with the ORG group (P < 0.05), but the total hospitalization days, postoperative fluid intake time, proportion of antibiotic use, and lung infection status were consistent. The ESD/EMR group had a lower incidence of incision site infection and postoperative abdominal distension compared with that of the surgery groups (P < 0.05). Five patients required radical surgery after undergoing ESD/EMR (The patients had residual tissue margin cancer), while none of the patients had switched to ORG during LARG. Surgery had advantages over ESD/EMR in terms of lymph node dissection (P < 0.05). No significant differences were observed in the postoperative complications such as upper gastrointestinal bleeding, perforation, incision hernia, reoperation and recurrence (P > 0.05). The 5-year postoperative survival rates of patients in the three groups were 94.2% (ESD/EMR), 93.5% (LARG), and 94.7% (ORG), respectively, with no significant differences (P > 0.05). The binary logistics multivariate analysis showed that the tumor size, invasion depth, vascular invasion, and differentiated degree were risk factors for death in patients with gastric cancer.

CONCLUSIONS

No significant difference was observed between ESD/EMR and radical surgery. However, standardized criteria for excluding metastatic lymph nodes should be established to promote ESD/EMR.

Global research trends of endoscope in early gastric cancer: A bibliometric and visualized analysis study over past 20 years

Objectives

Early gastric cancer (EGC) is defined as aggressive gastric cancer involving the gastric mucosa and submucosa. Early detection and treatment of gastric cancer are beneficial to patients. In recent years, many studies have focused on endoscopic diagnosis and therapy for EGC. Exploring new methods to analyze data to enhance knowledge is a worthwhile endeavor, especially when numerous studies exist. This study aims to investigate research trends in endoscopy for EGC over the past 20 years using bibliometric analysis.

Methods

Original articles and reviews examining the use of endoscopy for EGC published from 2000 to 2022 were retrieved from the Web of Science Core Collection, and bibliometric data were extracted. Microsoft Office Excel 2016 was used to show the annual number of published papers for the top 10 countries and specific topics. VOSviewer software was used to generate network maps of the cooccurrences of keywords, authors, and topics to perform visualization network analysis.

Results

In total, 1,009 published papers met the inclusion criteria. Japan was the most productive country and had the highest number of publications (452, 44.8%), followed by South Korea (183, 18.1%), and China (150, 14.9%). The National Cancer Center of Japan was the institution with the highest number of publications (48, 4.8%). Ono was the most active author and had the highest number of cited publications. Through the network maps, exploring endoscopic diagnosis and therapy were major topics. Artificial intelligence (AI), convolutional neural networks (CNNs), and deep learning are hotspots in endoscopic diagnosis. Helicobacter pylori eradication, second-look endoscopy, and follow-up management were examined.

Conclusions

This bibliometric analysis investigated research trends regarding the use of endoscopy for treating EGC over the past 20 years. AI and deep learning, second-look endoscopy, and management are hotspots in endoscopic diagnosis and endoscopic therapy in the future.

Red blood cell distribution width as a novel marker for predicting bleeding after endoscopic resection for early gastric cancer

Objectives

Endoscopic resection (ER) is a minimally invasive treatment for early gastric cancer (EGC); however, there is a high occurrence of bleeding. This study aimed to clarify the significance of red blood cell distribution width (RDW) as a predictive risk factor for bleeding after ER for EGC.

Methods

We conducted a retrospective study based on data for patients who underwent ER for EGC from 2019 to 2021. This study included 79 lesions in 54 patients who underwent ER for EGC. The primary outcome was the association between RDW before ER and bleeding within 28 days of treatment. Receiver operating characteristic (ROC) curves were constructed, wherein areas under the curve (AUCs) and 95% confidence intervals were calculated to compare the discriminatory power of RDW for predicting bleeding.

Results

Endoscopic submucosal dissection was used as the resection method for 73 lesions, whereas endoscopic mucosal resection was used for six lesions. En bloc resection was performed in all cases. There were no cases of perforation; however, bleeding after ER occurred in five cases (9.3%). ROC curve analysis of bleeding after ER showed that the AUC was 0.843 with a good diagnostic performance. When the cut-off value of RDW was set at 14.4%, sensitivity and specificity were 80% and 85.7%, respectively. There was a bleeding rate of 36.4% (4/11) at an RDW of ≥14.4%, which was significantly higher than that of 2.3% (1/43) at an RDW of <14.4%.

Conclusion

RDW can be a predictor of bleeding risk after ER for EGC.

Efficacy of the specialized scissor-type knife for gastric endoscopic submucosal dissection: a propensity score matched retrospective study

Background and study aims  Prevention of bleeding and perforation during gastric endoscopic submucosal dissection (ESD) is important. Scissor-type knives can accurately grasp and incise the targeted tissue using electrosurgical currents, thereby eliminating unexpected incisions. The SB Knife GX, a scissor-type knife specialized for gastric ESD, was released in June 2016 in Japan. The aim of the present study was to evaluate the efficacy and safety of gastric ESD using the SB Knife GX. Patients and methods  A total of 716 patients who underwent gastric ESD at Hiroshima University Hospital between July 2016 and December 2020 were retrospectively reviewed. From these, 671 patients underwent ESD using the IT Knife 2 (IT-2 group), while 45 underwent ESD using an SB Knife GX (SB-GX group). After propensity score matching, the procedure time, specimen size, en bloc and complete resection rates, and intraoperative bleeding, delayed bleeding, and perforation rates were evaluated. Results  No significant differences were observed in mean procedure time (SB-GX group: 115 ± 165 min; IT-2 group: 95 ± 61 min; P  = 0.82) and en bloc and complete resection rates between the two groups. Intraoperative bleeding rates were significantly lower in the SB-GX group than in the IT-2 group (18 % vs. 40 %; P  = 0.01), and there were no differences in delayed bleeding (4 % vs. 4 %) or perforation (0 % vs. 4 %) between the two groups. Conclusions  The SB Knife GX was proven to be useful for control of intraoperative bleeding during gastric ESD, although the procedure time tended to be longer.

Vonoprazan vs. Lansoprazole for the treatment of endoscopic submucosal dissection induced gastric ulcer: a systematic review and meta-analysis

BACKGROUND

Vonoprazan is a potassium competitive acid blocker (P-CAB) approved in Japan in 2014 to treat endoscopic submucosal dissection (ESD)-induced ulcers and bleeding or perforation. Therefore, this meta-analysis aimed to determine whether Vonoprazan is more effective than Lansoprazole in the treatment of ESD-induced ulcers which include ulcer healing and shrinking rate, among others.

METHODS

Randomized controlled trials (RCT) and retrospective studies were collected from the PubMed (Medline), Embase, Web of science and Cochrane Library databases. Meanwhile, studies were selected according to predetermined qualification criteria and data were extracted by two researchers. The quality of the methods for published papers was evaluated using the modified Jadad scale.

RESULTS

Five studies were included in this meta-analysis, the ulcer healing rate effect was not significantly higher in the intervention groups than in the control groups at 4 weeks, [OR：1.07 (0.51, 2.22), 95% CI, I2=2%, Z=0.18, P=0.86]. There was no significant difference in the ulcer shrinkage rate at 4 weeks [MD：0.20 (-1.51, 1.92), 95% CI, I2=0%, P=0.82] and 8 weeks [MD: -0.09 (-0.30, 0.12), 95% CI, I2=0%, P=0.39].

CONCLUSION

There was no significant difference between Vonoprazan and Lansoprazole in the ulcers induced by treatment after 4 weeks and 8 weeks of treatment with ESD.

Design and biopharmaceutical preclinical characterisation of a new thermosensitive hydrogel for the removal of gastric polyps

BACKGROUND AND AIMS

Submucosal injection agents are widely used solutions in gastric polyp resection techniques. Currently, many different solutions are used in clinical practice, but most are not authorised for this use or are not biopharmaceutical characterised. The objective of this multidisciplinary work is to test the efficacy of a novel thermosensitive hydrogel designed specifically for this indication.

METHODS

A mixture design of various components (Pluronic®, hyaluronic acid and sodium alginate) was carried out to select the combination with optimal properties for this use. Three final thermosensitive hydrogels were selected on which biopharmaceutical characterisation was performed and stability and biocompatibility were analysed. Efficacy in maintaining elevation was tested ex vivo on pig mucosa and in vivo in pigs RESULTS: The mixture design allowed selection of the ideal combinations of agents for the characteristics sought. The thermosensitive hydrogels studied showed high values of hardness and viscosity at 37 °C, maintaining good syringeability. One of them demonstrated superiority in maintaining polyp elevation in the ex vivo assay and non-inferiority in the in vivo assay.

CONCLUSION

The thermosensitive hydrogel specifically designed for this use is promising both for its biopharmaceutical characteristics and for its demonstrated efficacy. This study lays the foundation for evaluating the hydrogel in humans.

Gaussian affinity and GIoU-based loss for perforation detection and localization from colonoscopy videos

PURPOSE

Endoscopic submucosal dissection (ESD) is a minimally invasive treatment for early gastric cancer. However, perforations may happen and cause peritonitis during ESD. Thus, there is a potential demand for a computer-aided diagnosis system to support physicians in ESD. This paper presents a method to detect and localize perforations from colonoscopy videos to avoid perforation ignoring or enlarging by ESD physicians.

METHOD

We proposed a training method for YOLOv3 by using GIoU and Gaussian affinity losses for perforation detection and localization in colonoscopic images. In this method, the object functional contains the generalized intersection over Union loss and Gaussian affinity loss. We propose a training method for the architecture of YOLOv3 with the presented loss functional to detect and localize perforations precisely.

RESULTS

To qualitatively and quantitatively evaluate the presented method, we created a dataset from 49 ESD videos. The results of the presented method on our dataset revealed a state-of-the-art performance of perforation detection and localization, which achieved 0.881 accuracy, 0.869 AUC, and 0.879 mean average precision. Furthermore, the presented method is able to detect a newly appeared perforation in 0.1 s.

CONCLUSIONS

The experimental results demonstrated that YOLOv3 trained by the presented loss functional were very effective in perforation detection and localization. The presented method can quickly and precisely remind physicians of perforation happening in ESD. We believe a future CAD system can be constructed for clinical applications with the proposed method.

Efficacy and Safety of a Novel Hemostatic Peptide Solution During Endoscopic Submucosal Dissection: A Multicenter Randomized Controlled Trial

INTRODUCTION

To compare the effectiveness of the novel hemostatic peptide, TDM-621, with that of conventional hemostatic methods in treating intraoperative blood oozing during endoscopic submucosal dissection (ESD).

METHODS

This multicenter, open-label, randomized controlled trial involved 227 patients with gastric and rectal epithelial tumors in whom ESD was indicated. Patients in whom the source of blood oozing was difficult to identify with waterjet washing during the procedure and required hemostasis with hemostatic forceps were randomly assigned to the TDM-621 and control groups. The TDM-621 group (in which hemostasis was achieved with TDM-621, followed by coagulation hemostasis with hemostatic forceps, as needed) was compared with the control group (in which hemostasis was achieved with hemostatic forceps). The primary end point was the mean number of coagulations with hemostatic forceps, determined by a blinded independent review committee. The secondary end points were the rate of achievement of hemostasis with only TDM-621, the dosage of TDM-621, and adverse events in the TDM-621 group.

RESULTS

The mean number of coagulations with hemostatic forceps was significantly reduced in the TDM-621 group (1.0 ± 1.4) compared with that in the control group (4.9 ± 5.2) ( P < 0.001). The rate of hemostasis achievement with only TDM-621 was 62.2%; the mean dosage of TDM-621 was 1.75 ± 2.14 mL. The rates of grade ≥3 adverse events were 6.2% and 5.0% in the TDM-621 and control groups, respectively.

DISCUSSION

TDM-621 is a useful, easily operable hemostatic peptide for treatment of blood oozing during gastric and rectal ESD, with no serious safety concerns.

Association between perioperative management of antiplatelet agents and risk of post-endoscopic submucosal dissection bleeding in early gastric cancer: analysis of a nationwide multicenter study

BACKGROUND AND AIMS

Data are lacking regarding post-endoscopic submucosal dissection (ESD) bleeding in patients with early gastric cancer (EGC) who take antiplatelet agents (APAs), particularly in those taking thienopyridine and cilostazol. We aimed to clarify the association between the status of APA medication and post-ESD bleeding risk.

METHODS

This study is a secondary analysis using data from a recently conducted nationwide multicenter study in Japan. We retrospectively reviewed patients treated with APAs or on no antithrombotic therapy recruited from 33 institutions who underwent ESD for EGC between November 2013 and October 2016. The primary outcome of this study was the relationship between the rate of post-ESD bleeding and the status of each APA medication.

RESULTS

A total of 9736 patients were included in the analysis. Among 665 aspirin users, the continuation group was significantly associated with post-ESD bleeding (odds ratio [OR], 2.79; 95% confidence interval [CI], 1.77-4.37). Among 227 thienopyridine users, the aspirin or cilostazol replacement group was not significantly associated with post-ESD bleeding (OR, 1.85; 95% CI, .72-4.78). Among 158 cilostazol users, there was no significant association with post-ESD bleeding, irrespective of medication status. The rate of post-ESD bleeding was approximately 10% to 20% irrespective of the status of APA administration among dual-antiplatelet therapy users. No patients experienced thromboembolic events in this study.

CONCLUSIONS

Replacement of thienopyridine with aspirin or cilostazol may be acceptable for minimizing both the risk of post-ESD bleeding and thromboembolism in patients with EGC. In patients on cilostazol monotherapy undergoing ESD, continuation of therapy may be acceptable.

Endoscopic submucosal dissection using an ultrathin endoscope for superficial pharyngeal cancer: a prospective feasibility study (with video)

Background and study aims  Endoscopic submucosal dissection (ESD) of pharyngeal cancers with conventional endoscopes often is difficult, not only because of the narrow working space, but also because endoscope maneuverability in the pharynx is poor due to interference from the endotracheal tube and/or hyoid bone. However, we hypothesized that those problems could possibly be resolved by use of an ultrathin endoscope for ESD of superficial pharyngeal cancer. The aim of this prospective interventional study was to investigate the feasibility of ESD for superficial pharyngeal cancer using an ultrathin endoscope. Patients and methods  This feasibility study was conducted at NTT Medical Center Tokyo between June 2020 and September 2021, and data from a total of 20 consecutively superficial pharyngeal cancers were analyzed. The primary outcome measure was the R0 resection rate. The ESD completion rate, en bloc resection rate, procedure time, and frequency of intraoperative and postoperative adverse events (AEs) were also evaluated as secondary outcome measures. Results  Data from 16 patients with 20 lesions were included in the analysis. All of the lesions were successfully resected by ultrathin endoscope ESD, and the en bloc and R0 resection rates were 100 % and 85.0 % (17/20), respectively; the procedure time was 37.8 ± 28.2 minutes. No intraoperative or postoperative AEs were encountered in any cases. Conclusions  ESD using an ultrathin endoscope is feasible for superficial pharyngeal cancers and has potential to be a safe and effective treatment option for these cancers.

Endoscopic Resection of Undifferentiated Early Gastric Cancer

Endoscopic resection (ER) is widely performed for early gastric cancer (EGC) with a negligible risk of lymph node metastasis (LNM) in Eastern Asian countries. In particular, endoscopic submucosal dissection (ESD) leads to a high en bloc resection rate, enabling accurate pathological evaluation. As undifferentiated EGC (UD-EGC) is known to result in a higher incidence of LNM and infiltrative growth than differentiated EGC (D-EGC), the indications for ER are limited compared with those for D-EGC. Previously, clinical staging as intramucosal UD-EGC ≤2 cm, without ulceration, was presented as 'weakly recommended' or 'expanded indications' for ER in the guidelines of the United States, Europe, Korea, and Japan. Based on promising long-term outcomes from a prospective multicenter study by the Japan Clinical Oncology Group (JCOG) 1009/1010, the status of this indication has expanded and is now considered 'absolute indications' in the latest Japanese guidelines published in 2021. In this study, which comprised 275 patients with UD-EGC (cT1a, ≤2 cm, without ulceration) treated with ESD, the 5-year overall survival (OS) was 99.3% (95% confidence interval, 97.1%-99.8%), which was higher than the threshold 5-year OS (89.9%). Currently, the levels of evidence grades and recommendations for ER of UD-EGC differ among Japan, Korea, and Western countries. Therefore, a further discussion is warranted to generalize the indications for ER of UD-EGC in countries besides Japan.

Research trends in endoscopic applications in early gastric cancer: A bibliometric analysis of studies published from 2012 to 2022

Background

Endoscopy is the optimal method of diagnosing and treating early gastric cancer (EGC), and it is therefore important to keep up with the rapid development of endoscopic applications in EGC. This study utilized bibliometric analysis to describe the development, current research progress, hotspots, and emerging trends in this field.

Methods

We retrieved publications about endoscopic applications in EGC from 2012 to 2022 from Web of Science™ (Clarivate™, Philadelphia, PA, USA) Core Collection (WoSCC). We mainly used CiteSpace (version 6.1.R3) and VOSviewer (version 1.6.18) to perform the collaboration network analysis, co-cited analysis, co-occurrence analysis, cluster analysis, and burst detection.

Results

A total of 1,333 publications were included. Overall, both the number of publications and the average number of citations per document per year increased annually. Among the 52 countries/regions that were included, Japan contributed the most in terms of publications, citations, and H-index, followed by the Republic of Korea and China. The National Cancer Center, based in both Japan and the Republic of Korea, ranked first among institutions in terms of number of publications, citation impact, and the average number of citations. Yong Chan Lee was the most productive author, and Ichiro Oda had the highest citation impact. In terms of cited authors, Gotoda Takuji had both the highest citation impact and the highest centrality. Among journals, Surgical Endoscopy and Other Interventional Techniques had the most publications, and Gastric Cancer had the highest citation impact and H-index. Among all publications and cited references, a paper by Smyth E C et al., followed by one by Gotoda T et al., had the highest citation impact. Using keywords co-occurrence and cluster analysis, 1,652 author keywords were categorized into 26 clusters, and we then divided the clusters into six groups. The largest and newest clusters were endoscopic submucosal dissection and artificial intelligence (AI), respectively.

Conclusions

Over the last decade, research into endoscopic applications in EGC has gradually increased. Japan and the Republic of Korea have contributed the most, but research in this field in China, from an initially low base, is developing at a striking speed. However, a lack of collaboration among countries, institutions, and authors, is common, and this should be addressed in future. The main focus of research in this field (i.e., the largest cluster) is endoscopic submucosal dissection, and the topic at the frontier (i.e., the newest cluster) is AI. Future research should focus on the application of AI in endoscopy, and its implications for the clinical diagnosis and treatment of EGC.

Efficacy of using red dichromatic imaging throughout endoscopic submucosal dissection procedure

BACKGROUND

Management of bleeding during endoscopic submucosal dissection (ESD) is critical. Red Dichromatic Imaging (RDI), a novel image-enhanced endoscopy technology, has been reported to improve the visibility of deep vessels and bleeding source compared to white light imaging (WLI). We hypothesized that using RDI during the entire cutting process (full time RDI ESD: FTR-ESD), higher R0 resection rate, shorter procedure time and fewer complications could be achieved. Therefore, the aims of the present study were to investigate the efficacy and safety of FTR-ESD.

METHODS

This retrospective observational study included a total of 82 consecutive patients who underwent ESD by a single expert endoscopist for 40 esophageal, 17 gastric and 25 colorectal cancers at our institution from January 2018 to March 2021. The clinicopathological data were collected from patients' medical records and the treatment outcomes were analyzed according to the treatment phase (early; 57 WLI-ESD and late; 25 FTR-ESD).

RESULTS

The median of the greatest diameter of resected specimen was 40.0 mm. The median procedure time was relatively shorter in the FTR-ESD group (35 min) than in the WLI-ESD group (40 min), but the difference was not statistically significant (p = 0.34). The median dissection speed in the FTR-ESD group (27.23 mm²/min) was significantly faster than that in the WLI-ESD group (20.94 mm²/min) (p = 0.025). The dissection speed was not different among different organs. A multivariate analysis revealed that tumor size (more than 30 mm) and FTR-ESD were significant independent factors contributing to faster dissection speed (p < 0.05). There were no significant differences in the rates of en bloc resection, HM0, VM0 or occurrence of adverse events between WLI-ESD and FTR-ESD.

CONCLUSIONS

FTR-ESD significantly increases the dissection speed compared to WLI-ESD. FTR-ESD can be performed safely and therapeutic outcomes in FTR-ESD are comparable with WLI-ESD. A further multicenter prospective study is warranted to confirm our results.

Clinicopathological features of endoscopically treated early gastric cancer with lymphovascular infiltration

PURPOSE

Lymphovascular infiltration (LVI) may play a critical role in radicality and prognostic assessment of early gastric cancer (EGC). However, risk factors for LVI in endoscopically resected EGC remain unknown. This study evaluated the clinicopathological characteristics and prognoses of patients who underwent endoscopic resection of EGC to identify potential risk factors of LVI.

METHODS

A cross-sectional study of patients who received gastric endoscopic submucosal dissection between February 1, 2012, and December 31, 2019, at two institutions was conducted. Among 1,462 lesions, 943 met the criteria for radical treatment considering features other than LVI and were included. The lesions were classified based on the presence of LVI. The clinicopathological characteristics of the two groups were compared.

RESULTS

LVI was detected in 17 lesions (1.8%). The positivity rates of LVI were 0.7% (7/903) for intramucosal cancer and 25% (10/40) for submucosally invasive cancer. The LVI positivity rate was significantly higher for mixed-type cancer (lesions containing differentiated and undifferentiated-type carcinoma) than for non-mixed-type cancer (35.3 vs. 2.8%; P < 0.001) and for submucosally invasive cancer than for intramucosal cancer (58.8 vs. 3.2%; P < 0.001). In the multivariate logistic regression analysis, independent risk factors for LVI were mixed-type cancer (odds ratio; 95% confidence interval: 23.9; 5.0-115; P < 0.001) and submucosal invasion (58.7; 16.0-215; P < 0.001).

CONCLUSIONS

Mixed-type cancer and submucosal invasion were risk factors for LVI in endoscopically resected EGC. These factors may play a critical role in the radicality and prognostic assessment of EGC.

Risk and prognostic factors of invasive gastric cancer detection during surveillance endoscopy: Multi-institutional cross-sectional study

OBJECTIVES

Esophagogastroduodenoscopy (EGD) is important for the detection of curable gastric cancer (GC). However, there are no appropriate surveillance data during routine endoscopic inspections. This study aimed to clarify the risk factors of pT1b or deeper GC detection during surveillance endoscopy.

METHODS

This was a retrospective, multicenter, cross-sectional study conducted in 15 Japanese hospitals. We retrospectively analyzed patients with GC who had previously undergone surveillance endoscopy at each institution from January 2014 to March 2020. Patients who had undergone gastrectomy, non-infection of Helicobacter pylori (Hp), and those with intervals <3 months or >10 years from a previous endoscopy were excluded.

RESULTS

In total, 1085 patients with GCs detected during surveillance endoscopy were enrolled. The multivariate logistic analysis revealed that current Hp infection (odds ratio [OR] 2.18; 95% confidence interval [CI] 1.50-3.16) and a surveillance interval of >1.5 years (OR 1.96; 95% CI 1.35-2.84) were independent risk factors for pT1b or deeper GC. The 5-year disease-specific survival (5y-DSS) rate of GC was significantly lower in patients with surveillance interval of >1.5 years than in those with surveillance interval of ≤1.5 years (93.7% vs. 98.3%, P < 0.001). Similarly, the 5y-DSS rate of GC was significantly lower in patients with active Hp infection than in those without (93.7% vs. 99.4%, P < 0.001).

CONCLUSION

In this study, a surveillance interval of >1.5 years and current Hp infection were independent risk factors for detecting pT1b or deeper GC. Additionally, these factors were poor prognostic factors of the detected GC during surveillance endoscopy.

Feasibility, efficacy, and cautionary note of endoscopic resection for gastric tube cancer after esophagectomy

BACKGROUND

Gastric tube cancer (GTC), whose usual histology is adenocarcinoma, occurs frequently as a result of improved survival after esophagectomy. Whether endoscopic resection (ER) for GTC is safe and suitable and guidelines for treatment and follow-up remains unclear.

METHODS

Patients with GTC who underwent ER at Kanagawa Cancer Center Hospital between 1997 and 2020 were studied retrospectively to evaluate clinical characteristics and short- and long-term outcomes.

RESULTS

Twenty-two consecutive patients with 43 lesions were treated in 42 sessions of ER. Lesions were discovered at a median of 9.0 (0-21.8) years after esophageal surgery. Nine (40.9%) patients had multiple lesions at the time of the initial ER session. However, six (54.5%) of the 11 co-existing lesions were overlooked. The location of the middle third was an estimated risk factor for overlooking (p = 0.028). In endoscopic submucosal dissection (ESD) cases, the en bloc dissection rate was as high as 97.1%, and the rates of bleeding, perforation, and aspiration pneumonitis were 17.6%, 0%, and 2.9%, respectively. The bleeding rate was relatively higher than that in usual gastric ESD. Twelve patients (54.5%) experienced synchronous and/or metachronous multiple GTCs during their life span. Thirteen (61.9%) patients died during the median follow-up period of 5.9 (0.7-15.5) years. One patient (7.7%) died of GTC recurrence, 15.4 years after the initial non-curative ER date; 3 (23.1%) patients died of esophageal cancer recurrence, and 3 (23.1%) died of other organ malignancies. The 5-year overall survival rate was 85.0%, and the 5-year disease-specific survival rate was 100%.

CONCLUSIONS

ER is feasible for GTCs. However, the rate of bleeding was high in ESD cases. Life-long endoscopic screening of metachronous lesions is desirable. Care should be taken not to overlook lesions in the middle third of the gastric tube. Early detection of esophageal cancer recurrence and other organ malignancies may improve prognosis.

Effectiveness of a novel traction device in endoscopic submucosal dissection for colorectal lesions

BACKGROUND

Among all types of superficial gastrointestinal (GI) neoplasms, colorectal lesions are recognized as one of the most difficult locations to operate, due to the limited operation space, physiological bends, poor visualization of the submucosal dissection plane sheltered by colorectal crinkle wall, and the thin intestinal mucosa layer which is easy to perforation. The purpose of this prospective study is to evaluate the feasibility, efficacy, and safety of a novel endoscopic traction technique in assisting the endoscopic submucosal dissection (ESD) procedure in colorectal lesions.

METHOD

A total of 117 patients with colonic lesions who underwent endoscopic treatment were enrolled between August 2020 and January 2021 at the endoscopic center of Beijing Chao-yang Hospital of Capital Medical University. Based on whether traction device was used during the operation, 60 and 57 patients were assigned to the conventional ESD group and clips and rubber band triangle traction-assisted ESD group (CRT-ESD, in which three clips and a rubber band were used to form an elastic triangular traction device), respectively. The total procedure time (TPT), submucosal dissection time (SDT), submucosal dissection speed (SDS), and rate of adverse events of the two groups were analyzed.

RESULTS

After excluding patients who did not undergo treatment (conventional ESD, 1; CRT-ESD, 4), 112 patients were included in the study (conventional ESD, 59; CRT-ESD, 53). The baseline characteristics of the patients were well balanced between the two groups. The TPT (58.71 ± 26.22 min vs 33.58 ± 9.88 min, p < 0.001) and SDT (49.24 ± 23.75 min vs 26.34 ± 8.75 min, p < 0.001) were significantly different between the conventional ESD group and CRT-ESD group. The CRT-ESD group had significantly higher SDS than that of the traditional ESD group (0.54 ± 0.42 cm2/min vs 0.89 ± 0.40 cm2/min, p < 0.001). There were 4 (6.8%) cases of perforation in the traditional ESD group, and no perforation occurred in traction-assisted ESD.

CONCLUSIONS

Compared with traditional ESD, CRT-ESD with clip and rubber band is both safer and more effective in the treatment of colorectal lesions.

Doppler probe method to reduce delayed bleeding after endoscopic submucosal dissection in the stomach: a propensity-score matched study (with video)

BACKGROUND

Prophylactic coagulation after gastric endoscopic submucosal dissection (ESD) decreases the rate of delayed bleeding; however, it cannot prevent bleeding completely, and delayed bleeding may occur from non-exposed vessels that were not detected immediately after ESD or where prophylactic coagulation was inadequate. Doppler monitoring systems which can evaluate vascular flow have been recently introduced in the endoscopic field. We developed the Doppler probe method (DOP) using the novel system and conducted a comparative study.

METHODS

Data were retrospectively collected at a tertiary hospital between January 2017 and May 2021. Patients who underwent DOP were matched to those who did not (no-DOP, 1:3 ratio). After successful ESD, DOP was performed, and coagulation was additionally performed as necessary. The primary outcome was the rate of 30-day delayed bleeding.

RESULTS

Fifty DOP patients were matched to 151 no-DOP patients. Although the differences were not statistically significant, the DOP group had lower rates of delayed bleeding (2.0% vs. 8.6%, P = 0.11; risk differences, 6.6%; 95% confidence interval [CI] 1.2-12.1%), readmission due to bleeding (0% vs. 2.7%), and blood transfusion (2.0% vs. 3.3%) compared to the no-DOP group. In the whole study population (n = 245), the log-rank test revealed that DOP was correlated to a lower incidence of delayed bleeding (P = 0.036). The Cox regression model revealed a marginally significant effect on delayed bleeding (hazard ratio = 0.17, 95% CI 0.022-1.26, P = 0.082). No procedure-related adverse events were observed.

CONCLUSION

DOP is safe and may reduce delayed bleeding; however, further prospective studies are required to validate our findings.

Demarcation Line Determination for Diagnosis of Gastric Cancer Disease Range Using Unsupervised Machine Learning in Magnifying Narrow-Band Imaging

Background and Aims: It is important to determine an accurate demarcation line (DL) between the cancerous lesions and background mucosa in magnifying narrow-band imaging (M-NBI)-based diagnosis. However, it is difficult for novice endoscopists. We aimed to automatically determine the accurate DL using a machine learning method. Methods: We used an unsupervised machine learning approach to determine the DLs. Our method consists of the following four steps: (1) an M-NBI image is segmented into superpixels using simple linear iterative clustering; (2) the image features are extracted for each superpixel; (3) the superpixels are grouped into several clusters using the k-means method; and (4) the boundaries of the clusters are extracted as DL candidates. The 23 M-NBI images of 11 cases were used for performance evaluation. The evaluation investigated the similarity of the DLs identified by endoscopists and our method, and the Euclidean distance between the two DLs was calculated. For the single case of 11 cases, the histopathological examination was also conducted to evaluate the proposed system. Results: The average Euclidean distances for the 11 cases were 10.65, 11.97, 7.82, 8.46, 8.59, 9.72, 12.20, 9.06, 22.86, 8.45, and 25.36. The results indicated that the proposed method could identify similar DLs to those identified by experienced doctors. Additionally, it was confirmed that the proposed system could generate pathologically valid DLs by increasing the number of clusters. Conclusions: Our proposed system can support the training of inexperienced doctors as well as enrich the knowledge of experienced doctors in endoscopy.

Novel image enhancement technology that helps find bleeding points during endoscopic submucosal dissection of gastric neoplasms

BACKGROUND AND AIM

The management of bleeding during endoscopic submucosal dissection (ESD) is critical and related to the procedure time. We collaborated on a new image enhancement algorithm with parameter optimization for clinical use being developed by FUJIFILM Co. and processed white light image data offline to evaluate the effectiveness of this technology. This study aims to evaluate the clinical usefulness of this technology.

METHODS

Eighteen video scenes of bleeding points from five gastric ESDs were selected and processed by the new image enhancement algorithm. The time until a bleeding point was found, visibility of a bleeding point, and color abnormality of the submucosal layer were evaluated by ESD experts, ESD trainees, and endoscopy trainees. The color differences between the bleeding point and the surroundings in CIE-L*a*b* color space were calculated in the original and enhanced images.

RESULTS

The time until a bleeding point was found in the enhanced videos was significantly shorter than that in the original videos (11.10 s vs 13.85 s) (P = 0.017). On a 5-point (-2 to +2) Likert scale of visibility, the enhanced image was slightly superior to the original (+0.45), and the appearance of the submucosa was comparable between images (+0.14). The color difference among the bleeding areas on the enhanced images was significantly larger than that on the original images (10.93 vs 8.36).

CONCLUSION

This novel image enhancement algorithm emphasizes the color difference between a bleeding point and the surrounding area, which would help find bleeding points faster during ESD for the less experienced endoscopists.

Studies on endoscopic submucosal dissection in the past 15 years: A bibliometric analysis

Background and aims

Endoscopic submucosal dissection (ESD) is an advanced minimally invasive technique for en bloc resection of superficial gastrointestinal lesions, which is drawn an increasing attention from its emergence. This bibliometric analysis is to evaluate the origin, current hotspots, and research trends on ESD.

Methods

A total of 2,131 publications on ESD from 2006 to 2020 were obtained from the Web of Science Core Collection (WoSCC) database. Bibliometric visualization analyses of countries/regions, institutes, authors, journals, references and keywords were performed by CiteSpace V.5.8.R3.

Results

The quantity of publications on ESD increased significantly during the past 15 years. Japan occupied the leading position in terms of research power. Professor Yutaka Saito, together with the institute he belongs, the Endoscopy Division, National Cancer Center Hospital, Tokyo, Japan, were the most productive author and institute, respectively. Colorectal ESD led the main thematic concentrations in ESD research. The most prolific journal was Gastrointestinal Endoscopy. European ESD Guideline was the most frequently co-cited reference. Guideline, meta-analysis, endoscopic resection, poly-glycolic acid sheet, Barrett's esophagus, fibrin glue, risk and colorectal neoplasm will be the active research hotspots in the future.

Conclusions

These findings provide the trends and frontiers in the field of ESD, as well as valuable information for clinicians and scientists to discover the future perspectives with potential collaborators.

Antithrombotics increase bleeding after endoscopic submucosal dissection for gastric cancer: Nationwide propensity score analysis

OBJECTIVES

Post-operative bleeding is the most common adverse event in endoscopic submucosal dissection (ESD) for early gastric cancer (EGC). Patients taking antithrombotic agents has increased. We evaluated the influence of antithrombotic agents on delayed bleeding in ESD for EGC.

METHODS

This was a post hoc analysis of nationwide, multicenter, retrospective cohort study in Japan. Altogether, 11,452 patients who underwent ESD for EGC in 33 institutions between November 2013 and October 2016 were enrolled. The primary outcome was the incidence of delayed bleeding in patients with or without antithrombotic agents. The secondary outcome was the incidence of delayed bleeding in those who took each antithrombotic agent and the cessation status of its use compared with each matched pair of patients. We used propensity matching and inverse probability of treatment weighting (IPTW) analyses.

RESULTS

There were 1353 matched pairs of patients. The incidence of delayed bleeding was 2.8% and 10.7% in those without and with antithrombotic agents, respectively (odds ratio [OR] 4.15, 95% confidence interval [CI] 2.88-5.99; P < 0.001). The IPTW analysis showed similar results (OR 4.21, 95% CI 3.48-5.08; P < 0.001). Antiplatelets, anticoagulants, and their combination increased such incidence. Heparin bridging therapy had high OR (8.80), and the continuation (OR 3.46) and cessation (OR 2.95) of antithrombotic agent use had similar risk.

CONCLUSIONS

Antithrombotic agents increased the incidence of delayed bleeding in patients who underwent ESD for EGC. Continuing antithrombotics may be more appropriate than heparin bridging therapy.

Influence of hospital volume on bleeding after endoscopic submucosal dissection for early gastric cancer in Japan: a multicenter propensity score-matched analysis

BACKGROUND

Information on whether there is a relationship between hospital volume and bleeding after endoscopic submucosal dissection (ESD) for early gastric cancer (EGC) is limited. This study aimed to compare the bleeding rates after ESD for EGC according to the hospital volume.

METHODS

Patients who underwent ESD for EGC at 33 institutions in Japan between November 2013 and October 2016 were included in this multicenter retrospective study. Hospital volume was categorized into three groups, based on the average annual number of ESD procedures: low- and medium-volume group (LMVG), high-volume group (HVG), and very high-volume group (VHVG). The bleeding rate after ESD for EGC was compared between the three hospital volume groups after propensity score matching.

RESULTS

A total of 10,320 patients, including 2797 patients in the LMVG, 4646 patients in the HVG, and 2877 patients in the VHVG, were identified. Propensity score matching yielded 2002 patients in each hospital volume group, with an improved balance of confounding variables between the three groups. The bleeding rates in the LMVG, HVG, and VHVG were 4.3%, 3.7%, and 4.9%, respectively, and no significant difference was noted between the three groups.

CONCLUSIONS

The bleeding rate after ESD for EGC did not differ between hospitals in Japan. The finding indicated that ESD for EGC is equally feasible across Japanese hospitals of different volumes regarding bleeding after ESD.

Endoscopic Submucosal Dissection vs. Surgery for Superficial Esophageal Squamous Cancer: A Systematic Review and Meta-Analysis

Background

Esophageal cancer is one of the leading causes of morbidity and mortality across the world. Only one systematic review and meta-analysis has attempted to compare the morbidity and mortality outcomes in superficial esophageal squamous cancer patients undergoing endoscopic submucosal dissection (ESD) and esophagectomy (ESO), but with several limitations. This study aimed at comparing the outcomes of hospital stay duration, procedure duration, recurrence, complications, all-cause mortality, short-term survival, and long-term survival in patients with superficial esophageal squamous cancer undergoing ESD and ESO.

Methods

Six databases (Web of Science, PubMed, EMBASE, CENTRAL, Scopus, and MEDLINE) were systematically searched according to PRISMA guidelines for eligible studies. With the available literature, we conducted a random-effect meta-analysis to evaluate weighted effect size and odds ratios to determine the comparative morbidity and mortality outcomes between patients with superficial esophageal squamous cancer undergoing ESD and ESO.

Results

We found 16 eligible studies detailing 5,213 and 8,049 age- and sex-matched patients undergoing ESD and ESO, respectively. Meta-analysis revealed reduced hospital stay (Hedge’s g: -1.22) and procedure duration (g: -4.54) for patients undergoing ESD. We also observed significantly reduced risks for complications (odds ratio: 0.35) and all-cause mortality (OR: 0.56) in patients undergoing ESD. Differences in recurrence (OR: 0.95), short-term outcomes (OR: 1.10), and long-term survival (OR: 0.81) outcomes were not significantly different between ESD and ESO.

Conclusions

This meta-analysis provides evidence concerning the improved morbidity and mortality outcomes in superficial esophageal squamous cancer patients undergoing ESD as compared to ESO. The findings herein may aid in developing clinical awareness and assisting best practice guideline development for managing superficial esophageal squamous cancer.

Registration

PROSPERO, https://www.crd.york.ac.uk/prospero/#searchadvanced, CRD42021286212.

A novel, simple, and dedicated device for endoscopic mucosal defect closure

OBJECTIVES

Endoscopic submucosal dissection (ESD) has become popular, but complications such as postoperative bleeding remain an issue. Although some methods of closing a mucosal defect with a snare and clips have been reported to be effective and safe, the snare is not a dedicated device, and the procedure is difficult and time-consuming. We aimed to find an alternative method for defect closure after ESD by developing a dedicated device.

METHODS

We have improved five prototypes. The load on the stopper when starting to tighten and loosen a loop and the maximum load on the stopper and the movement distance of the thread when sliding the stopper were measured five times for each prototype. With the 5th prototype, we finalized the design and named it FLEXLOOP. Additionally, the material and shape of the outer tube were improved. Then, the usability of FLEXLOOP was evaluated in pigs. The operation time for closing mucosal defects with the snare or FLEXLOOP was measured five times.

RESULTS

We made FLEXLOOP, which had a lower load when sliding and a higher load when loosening than the snare. The improvement of the outer tube significantly reduced the load on the sheath when sliding it. We confirmed the feasibility of mucosal defect closure with FLEXLOOP in pigs. The median operation time was 563 s (range 340-679 s) with the snare and 355 s (range 303-455 s) with FLEXLOOP (p = 0.047).

CONCLUSIONS

FLEXLOOP can be a promising option for defect closure after ESD.

Traction method versus conventional endoscopic submucosal dissection for gastric epithelial neoplasms: A randomized controlled trial

INTRODUCTION

Endoscopic submucosal dissection (ESD) is an advanced therapeutic technique for en bloc resection of superficial gastrointestinal neoplasms. Although gastric ESD is minimally invasive and provides favorable outcomes, it is technically difficult and requires a long procedure time for dissection. The traction-assisted approach overcomes some of the difficulties of gastric ESD, but its ability to reduce the procedure time remains unclear. The traction-assisted approach using dental floss and a clip did not reduce procedure time in the total population, but it reduced procedure time for lesions limited to the greater curvature of the upper or middle of the stomach. Although the traction direction of the clip-with-line method may be limited to the oral side via the cardia, EndoTrac ESD may provide flexible traction at any time during the procedure. This prospective randomized control study has been designed to compare the efficacy and safety of EndoTrac and conventional gastric ESD.

METHODS/DESIGN

This multicenter, randomized control trial will enroll 150 patients at 2 hospitals in Japan undergoing EndoTrac or conventional ESD for gastric epithelial neoplasia. Patients with a single gastric epithelial neoplasm who meet the inclusion and exclusion criteria will be randomized to EndoTrac or conventional ESD. Patients will be randomized by a computer-generated random sequence with stratification by operator experience, tumor size, tumor location, and institution. The primary endpoint will be ESD procedure time, defined as the time from the start of the submucosal injection to the completion of resection. Other outcomes will include the rates of adverse events and pathological curability.

DISCUSSION

The ability of EndoTrac ESD to reduce the long procedure time and/or adverse events observed with conventional ESD can not only reduce physical stress on the patient, but can also reduce length of hospital stay and medical costs. Reduced technical difficulty will contribute to the widespread adoption of this ESD technique worldwide.

TRIAL REGISTRATION

University Hospital Medial Information Network Clinical Trials Registry (UMIN-CTR), ID: 000044450; Registered on June 6, 2021.https://upload.umin.ac.jp/cgi-open-bin/ctr/ctr_view.cgi?recptno=R000050485.

PROTOCOL VERSION NUMBER

1.1, March 1, 2022. Patient enrolment began on June 6, 2021 and is expected to be completed by July 19, 2025.

The safety and feasibility of endoscopic submucosal dissection using a flexible three-dimensional endoscope for early gastric cancer and superficial esophageal cancer: A prospective observational study

BACKGROUND AND AIM

Endoscopic submucosal dissection (ESD) is performed as one of standard treatments for patients with early gastric cancer (EGC) and superficial esophageal squamous cancer (SESCC). A prototype of a flexible endoscope with a 3-D system has been recently developed. This study aimed to investigate the safety and feasibility of ESD using a 3-D flexible endoscope (3-D ESD) for EGC and SESCC.

METHODS

This single-center, prospective, observational study enrolled patients who underwent planned 3-D ESD. The clinical outcomes, including the incidence of adverse events and treatment results, were analyzed. Visibility and manipulation during 3-D ESD were evaluated using a visual analog scale (VAS). We also evaluated the effect of the 3-D system on the endoscopist using VAS and the critical flicker fusion frequency (CFFF).

RESULTS

We analyzed 47 EGC and 20 SESCC cases. There are no bleeding cases that required transfusion and perforation during 3-D ESD in both EGC and SESCC patients. However, the incidence of delayed bleeding and delayed perforation was 1.5% (one case) each. The mean VAS scores for recognizing the submucosal layer during the submucosal dissection, visual perception of blood vessel, and depth perception were 72.7 ± 22.2, 74.7 ± 21.8, and 78.2 ± 19.9, respectively. In contrast, the mean VAS score for manipulation was 25.4 ± 19.7. Among endoscopists, there was no significant difference in the VAS of eyestrain and headache before and after ESD, and there was no significant difference in the CFFF.

CONCLUSION

The safety and feasibility of 3-D ESD for EGC and SESCC are acceptable in both patients and endoscopists.

Long-term outcomes of endoscopic submucosal dissection and surgery for undifferentiated intramucosal gastric cancer regardless of size

BACKGROUND

The clinical outcomes of endoscopic submucosal dissection (ESD) for undifferentiated (UD) intramucosal early gastric cancer (EGC) compared with those of surgery, regardless of lesion size, are not well known. Furthermore, there is a concern regarding the treatment plan before and after ESD in cases of UD intramucosal EGC within expanded indications.

AIM

To evaluate clinical outcomes of ESD compared with those of surgery in UD intramucosal EGC patients regardless of tumor size.

METHODS

We enrolled patients with UD intramucosal EGC after ESD with complete resection or surgery from January 2005 to August 2020 who met the within or beyond expanded indications with lesion size > 2 cm (the only non-curative factor). Overall, 123 and 562 patients underwent ESD and surgery, respectively. After propensity-score matching, clinical and long-term outcomes, i.e., recurrence-free survival (RFS) and overall survival (OS), were analyzed. The multivariable Cox proportional hazard model with treatment modality and ESD indication was used to evaluate the recurrence risk.

RESULTS

After matching, 119 patients each were finally enrolled in the ESD and surgery groups. The median length of hospital stay was shorter in the ESD group than surgery group (4.0 vs 9.0 days, P < 0.001). Four cases of recurrence after ESD were local recurrences, all of which occurred within 1 year. Total recurrence was seven (5.9%) and two (1.7%) in the ESD and surgery groups, respectively. No difference was observed between the two groups with respect to OS (P = 0.948). However, the ESD group had inferior RFS compared with the surgery group (P = 0.031). ESD was associated with the risk of recurrence after initial treatment in all enrolled patients (hazard ratio, 5.2; 95% confidence interval: 1.0-25.8, P = 0.045).

CONCLUSION

Although OS was similar between the two groups, surveillance endoscopy was important for the ESD than for the surgery group because RFS was inferior and local recurrence was an issue.

The Modified eCura System for Identifying High-Risk Lymph Node Metastasis in Patients with Early Gastric Cancer Resected by Endoscopic Submucosal Dissection

Background: Endoscopic submucosal dissection (ESD) is widely used for early gastric cancer (EGC) in patients without lymph node metastasis (LNM). Prediction of LNM after ESD is important to determine prognosis in patients with EGC. In this regard, the eCura system was applied to predict LNM after noncurative ESD for EGC. This study aimed to identify risk factors for LNM and improve the accuracy of the eCura system for predicting the risk of LNM after ESD. Methods: A total of 150 patients who underwent noncurative resection of EGC by ESD were retrospectively enrolled at five institutions in Japan. All patients underwent additional surgery with lymph node resection after ESD. The risk factors for LNM among clinicopathological parameters were examined and receiver operating characteristic curve (ROC) analysis was used to determine the optimal cutoff point for predicting high LNM risk using the modified eCura system. Results: Of 150 patients, 19 (13%) had LNM. In the multivariate analysis, lymphatic invasion, and tumor size >30 mm were independent risk factors for LNM. Using a cutoff score of ≥4 for predicting high risk based on the eCura system, the rate of LNM was significantly higher in the high-risk group (4–7 points) than in the low-risk group (0–3 points) (odds ratio 12.0, 95% confidence interval 3.7–54.2, p < 0.0001). Conclusions: An eCura score ≥4 may improve the prediction of LNM risk after ESD in patients with EGC in the intermediate-risk group (2–4 points) of the eCura system, suggesting better treatment strategies for patients. Further prospective and long-term follow-up studies are needed to validate the efficacy of the modified system.

A reliable nomogram model for predicting esophageal stricture after endoscopic submucosal dissection

ABSTRACT

Currently, endoscopic submucosal dissection (ESD) has gradually become the diagnosis and treatment of choice for initial esophageal cancer. However, the formation of esophageal stricture after ESD is one of its important complications. In this paper, we intend to identify the risk factors of esophageal stricture to develop a nomogram model to predict the risk of esophageal stricture and validate this model.A total, 159 patients were included in this study, including 21 patients with esophageal stenosis. Multivariate analysis showed that age greater than 60 years, high neutrophil-to-lymphocyte ratio, the extent of esophageal mucosal defect greater than 1/2, and postoperative pathological type of early esophageal squamous cell carcinoma were independent risk factors for predicting esophageal stricture. We constructed a nomogram model to predict esophageal stenosis by these 4 independent predictors.The prediction performance of the model was verified by the area under the receiver operating characteristic curve, the area under the receiver operating characteristic curve of the model was 0.889, and the sensitivity and specificity were 80.00% and 91.28%, respectively, indicating that the prediction performance of the model was good; The calibration curve constructed by internal cross-validation suggested that the predicted results of the nomogram agreed well with the actual observed values.The nomogram model has a high accuracy for predicting esophageal stricture after esophageal ESD and is extremely important to reduce or avoid the occurrence of esophageal stricture. But it needs more external and prospective validation.

Feasibility of gastric endoscopic submucosal dissection in elderly patients aged ≥ 80 years

BACKGROUND

Endoscopic resection, especially endoscopic submucosal dissection (ESD), is increasingly performed in elderly patients with early gastric cancer, and lesions beyond the expanded indications are also resected endoscopically in some patients. It is essential to assess whether gastric ESD is safe and suitable for elderly patients and investigate what type of lesions carry an increased risk of ESD-related complications.

AIM

To assess the efficacy and feasibility of gastric ESD for elderly patients, and define high-risk lesions and prognostic indicators.

METHODS

Among a total of 1169 sessions of gastric ESD performed in Kanagawa Cancer Center Hospital from 2006 to 2014, 179 sessions (15.3%) were performed in patients aged ≥ 80 years, and 172 of these sessions were done in patients with a final diagnosis of gastric cancer. These patients were studied retrospectively to evaluate short-term outcomes and survival. The short-term outcomes included the rates of en bloc resection and curative resection, complications, and procedure-related mortality. Curability was assessed according to the Japanese Gastric Cancer Treatment Guidelines 2010. Fisher’s exact test was used to statistically analyze risk factors. Clinical characteristics of each group were compared using Fisher’s exact test and Mann-Whitney U test. Survival rates at each time point were based on Kaplan-Meier estimation. Overall survival rates were compared between patients with gastric cancer in each group with use of the log-rank test. To identify prognostic factors that jointly predict the hazard of death while controlling for model overfitting, we used the least absolute shrinkage and selection operator (LASSO) Cox regression model including factors curative/ noncurative, age, gender, body mass index, prognostic nutritional index, Charlson comorbidity index (CCI), Glasgow prognostic score, neutrophil-to-lymphocyte ratio, and antithrombotic agent use. We selected the LASSO Cox regression model that resulted in minimal prediction error in 10-fold cross-validation. P < 0.05 was considered statistically significant.

RESULTS

The en bloc dissection rate was 97.1%, indicating that a high quality of treatment was achieved even in elderly patients. As for complications, the rates of bleeding, perforation and aspiration pneumonitis were 3.4%, 1.1% and 0.6%, respectively. These complication rates indicated that ESD was not associated with a particularly higher risk in elderly patients than in nonelderly patients. A dissection incision > 40 mm, lesions associated with depressions, and lesions with ulcers were risk factors for post-ESD bleeding, and location of the lesion in the upper third of the stomach was a risk factor for perforation in elderly patients (P < 0.05). Location of the lesion in the lower third of the stomach tended to be associated with a higher risk of bleeding. The overall survival (OS) did not differ significantly between curative and noncurative ESD (P = 0.69). In patients without additional surgery, OS rate was significantly lower in patients with a high CCI (≥ 2) than in those with a low CCI (≤ 1) (P < 0.001).

CONCLUSION

Gastric ESD is feasible even in patients aged ≥ 80 years. Observation without additional surgery after noncurative ESD is reasonable, especially in elderly patients with CCI ≥ 2.