Gastric ESD: current status and future directions of devices and training

Local recurrence after endoscopic submucosal dissection of gastric neoplastic lesions: special attention should be given also to safety margins

INTRODUCTION

The incidence of local recurrence following gastric endoscopic submucosal dissection (ESD) remains a clinical concern. We aimed to evaluate the impact of narrow safety margin (< 1 mm) on the recurrence rate.

METHODS

A retrospective cohort study was conducted across two centers. Cases of R0-ESD with subsequent recurrence were compared to matched controls in a 1:2 ratio in a case-cohort analysis.

RESULTS

Over a median period of 25 months (IQR 14-43), a recurrence rate of 3% (95%CI 1.7-4.3) was observed, predominantly (13/21) following R0 resections with favourable histology. Endoscopic retreatment was feasible in 18 of 21 recurrences. The proportion of R0-cases where the safety margin in both horizontal (HM) and vertical (VM) margin exceeded 1 mm was similarly distributed in the recurrence and non-recurrence group, representing nearly 20% of cases. However, cases with HM less than 1 mm, despite VM greater than 1 mm, nearly doubled in the recurrence group (7.7% vs. 3.9%), and tripled when both margins were under 1 mm (23.1% vs. 7.7%). Despite this trend, statistical significance was not achieved (p = 0.05). In the overall cohort, the only independent risk factor significantly associated with local recurrence was the presence of residual tumor at the HM (HM1) or not assessable HM (HMx) (OR 16.5 (95%CI 4.4-61.7), and OR 11.7 (95%CI 1.1-124.1), respectively).

CONCLUSIONS

While not common or typically challenging to manage, recurrence post-ESD warrants attention and justifies rigorous post-procedural surveillance, especially in patients with HM1, HMx, and probably also in those with R0 resections but narrow safety margin.

Factors associated with heterochronic gastric cancer development post-endoscopic mucosal dissection in early gastric cancer patients

BACKGROUND

Endoscopic mucosal resection is an innovative method for treating early gastric cancer and has been widely used in clinical practice.

AIM

To analyze the factors associated with the development of heterochronic gastric cancer in patients with early gastric cancer who had undergone endoscopic mucosal dissection (EMD).

METHODS

A cohort of patients with early gastric cancer treated using EMD was retrospectively analyzed, and patients who developed heterochronic gastric cancer after the surgery were compared with those who did not. The effects of patient age, sex, tumor size, pathological type, and surgical technique on the development of heterochronic gastric cancer were assessed using statistical analysis.

RESULTS

Of the 300 patients with early gastric cancer, 150 patients developed heterochronic gastric cancer after EMD. Statistical analysis revealed that patient age (P value = XX), sex (P value = XX), tumor size (P value = XX), pathological type (P value = XX), and surgical technique (P value = XX) were significantly associated with the occurrence of heterochronic gastric cancer.

CONCLUSION

Age, sex, tumor size, pathological type, and surgical technique are key factors influencing the occurrence of heterochronic gastric cancer after EMD in patients with early gastric cancer. To address these factors, postoperative follow-up and management should be strengthened to improve the prognosis and survival rate of patients.

Endoscopic submucosal dissection training: evaluation of an ex vivo training model with continuous perfusion (ETM-CP) for hands-on teaching and training in China

BACKGROUND

The existing ex vivo models of endoscopic submucosal dissection (ESD) cannot simulate intraoperative hemorrhage well. We aimed to establish an ESD training method by applying an ex vivo training model with continuous perfusion (ETM-CP).

METHODS

Four training sessions were conducted for 25 novices under the guidance of 2 experts. Eventually, 10 novices completed ESD operations on a total of 89 patients after the training. The resection effectiveness, resection speed, complication rate, and novice performance before and after the training were compared. The data regarding the effects of the training and the model were gathered through a questionnaire survey.

RESULTS

In terms of the simulation effect of the model, ETM-CP was evaluated as similar to the live pig in all aspects (P > 0.05). The questionnaire analysis revealed that the ESD theoretical knowledge, skill operation, and self-confidence of novices were improved after the training (P < 0.05). The resection time per unit area had a correlation with the number of training periods (rs = - 0.232). For novice performance, the resection time per unit area was shortened (P < 0.05). There was no difference in patient performance between the novice group and the expert group after the training in terms of en bloc resection, R0 resection, complication rate, endoscopic resection bleeding (ERB) score, muscularis propria injury (MPI) score, and resection time per unit area (P > 0.05).

CONCLUSION

The ETM-CP is effective for ESD training.

Prophylactic Clipping to Prevent Delayed Bleeding and Perforation After Endoscopic Submucosal Dissection and Endoscopic Mucosal Resection: A Systematic Review and Meta-analysis

BACKGROUND AND AIMS

To help prevent delayed adverse events after endoscopic surgery, endoscopists often place clips at the site. This meta-analysis aimed to assess the efficacy and safety of prophylactic clipping in the prevention of delayed bleeding and perforation after endoscopic submucosal dissection (ESD) and endoscopic mucosal resection (EMR).

METHODS

Multiple databases were searched from the inception dates to April 2021. And we included all relevant studies. Pooled odds ratio comparing the prophylactic clipped group versus nonprophylactic clipped group were calculated using the random effects model.

RESULTS

Twenty-seven articles fulfilled the inclusion criteria, with a total size of 8693 participants. There was statistically significant difference in prophylactic clipping versus no prophylactic clipping for delayed bleeding and perforation found in all studies (odds ratio: 0.35, 95% confidence interval: 0.25-0.49, P <0.01; odds ratio: 0.42, 95% confidence interval: 0.21-0.83, P <0.05; respectively). Besides, statistically significant difference was also found in subgroup analyses based on patients with lesions larger than 20 mm. Prophylactic clipping was more protective for duodenal delayed adverse events than colorectum. The use of clip closure was more protective to ESD-related delayed adverse events than EMR.

CONCLUSIONS

Prophylactic clipping after ESD and EMR was beneficial in preventing delayed bleeding and perforation.

Endoscopic Delivery of Polymers Reduces Delayed Bleeding after Gastric Endoscopic Submucosal Dissection: A Systematic Review and Meta-Analysis

New endoscopic approaches for the prevention of delayed bleeding (DB) after gastric endoscopic submucosal dissection (ESD) have been reported in recent years, and endoscopic delivery of biodegradable polymers for iatrogenic ulcer hemostasis and coverage has emerged as one of the most promising techniques for post-ESD management. However, the comparative efficacy of these techniques remains uncertain. We performed a systematic search of multiple databases up to May 2022 to identify studies reporting DB rates as outcomes in patients undergoing gastric ESD who were treated with subsequent endoscopic management, including endoscopic closure (clip-based methods and suturing), PGA sheet tissue shielding, and hemostatic powder/gel spray (including polymeric sealants and other adhesives). The risk ratios (RRs) of delayed bleeding in treatment groups and control groups were pooled, and the Bayesian framework was used to perform a network meta-analysis (NMA). Among these studies, 16 head-to-head comparisons that covered 2742 lesions were included in the NMA. Tissue shielding using PGA sheets significantly reduced the risk of DB by nearly two thirds in high-risk patients, while hemostatic spray systems, primarily polymer-based, reduced DB in low-risk patients nine-fold. Researchers should recognize the essential role of polymers in the management of ESD-induced ulcers, and develop and validate clinical application strategies for promising materials.

Nomograms Involving HER2 for Predicting Lymph Node Metastasis in Early Gastric Cancer

Objective: We aimed to establish a nomogram for predicting lymph node metastasis in early gastric cancer (EGC) involving human epidermal growth factor receptor 2 (HER2).

Methods: We collected clinicopathological data of patients with EGC who underwent radical gastrectomy and D2 lymphadenectomy at Ruijin Hospital, Shanghai Jiao Tong University School of Medicine between January 2012 and August 2018. Univariate and multivariate logistic regression analysis were used to examine the relationship between lymph node metastasis and clinicopathological features. A nomogram was constructed based on a multivariate prediction model. Internal validation from the training set was performed using receiver operating characteristic (ROC) and calibration plots to evaluate discrimination and calibration, respectively. External validation from the validation set was utilized to examine the external validity of the prediction model using the ROC plot. A decision curve analysis was used to evaluate the benefit of the treatment.

Results: Among 1,212 patients with EGC, 210 (17.32%) presented with lymph node metastasis. Multivariable analysis showed that age, tumor size, submucosal invasion, histological subtype, and HER2 positivity were independent risk factors for lymph node metastasis in EGC. The area under the ROC curve of the model was 0.760 (95% CI: 0.719–0.800) in the training set (n = 794) and 0.771 (95% CI: 0.714–0.828) in the validation set (n = 418). A predictive nomogram was constructed based on a multivariable prediction model. The decision curve showed that using the prediction model to guide treatment had a higher net benefit than using endoscopic submucosal dissection (ESD) absolute criteria over a range of threshold probabilities.

Conclusion: A clinical prediction model and an effective nomogram with an integrated HER2 status were used to predict EGC lymph node metastasis with better accuracy and clinical performance.

Comparison of the Efficacy of Polaprezinc Plus Proton Pump Inhibitor and Rebamipide Plus Proton Pump Inhibitor Treatments for Endoscopic Submucosal Dissection-induced Ulcers

GOALS

We assessed the efficacy of polaprezinc plus proton pump inhibitor (PPI) treatment for endoscopic submucosal dissection (ESD)-induced ulcer healing compared with rebamipide plus PPI treatment.

BACKGROUND

ESD has been widely used as a local treatment option that cures gastric neoplasms. However, it causes large and deep artificial ulcers, and there are no guidelines with regard to the optimal treatment durations and drug regimens for ESD-induced ulcers. Polaprezinc is effective for promoting ulcer healing and helps enhance the quality of ulcer healing.

STUDY

Two hundred ten patients with ESD-induced ulcers were randomly allocated to treatment with polaprezinc (150 mg/d) plus pantoprazole (40 mg/d) or treatment with rebamipide (300 mg/d) plus pantoprazole (40 mg/d). We evaluated the ulcer healing rate and condition of the ulcer at 4 weeks after dissection. The χ2 or Fisher exact test and the Student t test were used.

RESULTS

The ulcer healing rates at 4 weeks after dissection in the polaprezinc plus pantoprazole treatment group were not inferior compared with those in the rebamipide plus pantoprazole treatment group, both in the intention-to-treat analysis (90.3% and 91.4%, respectively, P=0.523) and per-protocol analysis (89.9% and 91.1%, respectively, P=0.531). The short procedure time was an independent predictive factor for a high ulcer healing rate (odds ratio: 0.975; 95% confidence interval: 0.958-0.993; P=0.006).

CONCLUSION

The polaprezinc plus PPI treatment showed noninferiority to rebamipide plus PPI treatment in the ulcer healing rate at 4 weeks after ESD.

Pushing the Envelope in Endoscopic Submucosal Dissection: Is It Feasible and Safe in Scarred Lesions?

BACKGROUND

Endoscopic submucosal dissection is an established advanced polypectomy technique to manage large colorectal polyps.

OBJECTIVE

The purpose of this study was to evaluate patients who had endoscopic submucosal dissection in the setting of significant scarring attributed to a previous intervention to determine whether this is safe and feasible.

DESIGN

The study used a prospectively maintained database.

SETTINGS

A scarred lesion was defined as a nonlifting polyp with a history of previous attempted removal with endoscopic mucosal resection, snare, or biopsy where there was no suspicion of malignancy.

PATIENTS

All consecutive patients in the previous 14 months were included.

INTERVENTION

Endoscopic submucosal dissection was the study intervention.

MAIN OUTCOME MEASURES

Thirty-day morbidity and mortality, readmission, length of stay, and recurrence were measured.

RESULTS

Ninety-one patients had endoscopic submucosal dissection over a 14-month period with a median polyp size of 31.5 mm (range, 20-45 mm). Eleven patients (12%) were confirmed as having significant scar. There were significantly more previous endoscopic mucosal resections in the scarred group (scarred: 63.6% vs nonscarred: 2.5%; p < 0.001). Significantly more of the scarred patients had their endoscopic submucosal dissection in the operating room versus the endoscopy suite (scarred: 82.0% vs nonscarred: 17.5%; p < 0.001). The 30-day morbidity rate was 18.7%. There were no mortalities. There was no difference in 30-day morbidity between scarred and nonscarred lesions (scarred: 9% vs nonscarred: 20%; p = 0.4). There were more day-case procedures in the nonscarred group (nonscarred: 93.7% vs scarred: 36.4%; p < 0.001). There was no malignancy on final pathology in the scarred group. There was no difference in readmission rate between the scarred and nonscarred lesions. The overall follow-up colonoscopy rate was 53%, and there were no polyp recurrences identified.

LIMITATIONS

The study was limited by its small sample size, single institute, surgeon experience, and short follow-up.

CONCLUSIONS

Not only is endoscopic submucosal dissection in patients who have scarred lesions technically feasible and safe, it avoids a bowel resection in the majority of patients who have exhausted other advanced endoscopy techniques. See Video Abstract at http://links.lww.com/DCR/B427.

EMPUJAR EL SOBRE EN LA DISECCIN ENDOSCPICA SUBMUCOSA ES FACTIBLE Y SEGURO EN LESIONES CICATRIZADAS

ANTECEDENTES:La disección endoscópica submucosa es una técnica de polipectomía avanzada establecida para tratar pólipos colorrectales grandes.OBJETIVO:Evaluar a pacientes que se sometieron a disección submucosa endoscópica en el contexto de cicatrices significativas debido a una intervención previa para determinar si esto es seguro y factible.DISEÑO:Base de datos mantenida prospectivamente.AJUSTE:Una lesión cicatrizada se definió como un pólipo que no se levanta con antecedentes de intento de extirpación previa con resección endoscópica de la mucosa, lazo o biopsia, donde no había sospecha de malignidad.PACIENTES:Todos los pacientes consecutivos en los últimos 14 meses.INTERVENCIÓN:Disección submucosa endoscópica.MEDIDAS DE RESULTADOS PRINCIPALES:Morbilidad y mortalidad a 30 días, reingreso, duración de la estadía, recurrencia.RESULTADOS:Noventa y un pacientes tuvieron disección submucosa endoscópica durante un período de 14 meses con tamaño de pólipo mediana de 31,5 mm (rango, 20 - 45 mm). Se confirmó que once pacientes (12%) tenían una cicatriz significativa. Hubo significativamente más resecciones de mucosa endoscópica previas en el grupo con cicatrices (con cicatrices: 63,6% vs. sin cicatrices: 2,5%, p <0,001). Significativamente más de los pacientes con cicatrices tuvieron su disección submucosa endoscópica en el quirófano en comparación con la sala de endoscopia (con cicatrices: 82% vs. sin cicatrices: 17.5%, p <0.001). La tasa de morbilidad a 30 días fue del 18,7%. No hubo muertes. No hubo diferencia en la morbilidad a 30 días entre las lesiones cicatrizadas y no cicatrizadas (cicatrizadas: 9% frente a no cicatrizadas: 20%, p = 0,4). Hubo más procedimientos ambulatorios en el grupo sin cicatrices (sin cicatrices: 93,7% frente a cicatrices: 36,36%, p <0,001). No hubo malignidad en la patología final en el grupo con cicatrices. No hubo diferencia en la tasa de reingreso entre las lesiones cicatrizadas y no cicatrizadas. La tasa general de colonoscopia de seguimiento fue del 53% y no se identificaron recurrencias de pólipos.LIMITACIONES:Tamaño de muestra pequeño, experiencia de un solo instituto y cirujanos y seguimiento corto.CONCLUSIÓN:La disección endoscópica submucosa en pacientes con lesiones cicatrizadas no solo es técnicamente factible y segura, sino que evita una resección intestinal en la mayoría de los pacientes que han agotado otras técnicas endoscópicas avanzadas. Consulte Video Resumen en http://links.lww.com/DCR/B427.

A comprehensive update on early gastric cancer: defining terms, etiology, and alarming risk factors

INTRODUCTION

Early gastric cancer (EGC) is a well-defined gastric malignancy that is limited to the mucosa or submucosa, irrespective of lymph node metastasis. At an early stage, gastric cancer often does not cause symptoms until it becomes advanced, and it is a heterogeneous disease and usually encountered in its late stages.

AREA COVERED

This comprehensive review will provide a novel insight into the evaluation of EGC epidemiology, defining terms, extensive etiology and risk factors, and timely diagnosis since prevention is an essential approach for controlling this cancer and reducing its morbidity and mortality.

EXPERT OPINION

The causative manner of EGC is complex and multifactorial. In recent years, researchers have made significant contributions to understanding the etiology and pathogenesis of EGC, and standardization in the evaluation of disease activity. Though the incidence of this cancer is steadily declining in some advanced societies owing to appropriate interventions, there remains a serious threat to health in developing nations. Early detection of resectable gastric cancer is crucial for better patient outcomes.

IS ENDOSCOPIC SUBMUCOSAL DISSECTION STILL LIMITED TO FEW TERTIARY CENTERS IN THE WEST? RESULTS FROM A NATIONAL SURVEY IN BRAZIL

BACKGROUND

Endoscopic submucosal dissection (ESD) enables en bloc excision of superficial neoplasms. Although ESD is widely practiced in Eastern countries like Japan, South Korea and China, its use in the West is supposed to be still limited to few tertiary centers.

OBJECTIVE

This study aimed to investigate the clinical practice of ESD in Brazil by means of an electronic questionnaire elaborated by the Brazilian Society of Digestive Endoscopy (SOBED).

METHODS

In October 2019, 3512 endoscopist members of SOBED were invited to respond to an electronic survey containing 40 questions divided into four topics: operator profile; clinical experience with ESD; adverse events and training. Informed consent was requested to all participants. The investigators reviewed all responses and considered valid if more than 50% of the questions were answered and additional information, when requested, was provided.

RESULTS

A total of 155 (4.4%) qualified responses entered the study. ESD has been practiced in 22 of 26 Federation States and majority of respondents (32.2%) have 10 to 20 years of practice. ESD has been performed more frequently in private hospitals (101 individuals, 66.9%) and private ambulatory centers (41 individuals, 27.1%). ESD was performed mainly in the stomach (72%), followed by the rectum (57%) and 80% of the individuals reported less than 25 operations. Twenty-four (15.4 %) individuals reported perforation and 4 (2.5%) of them reported postoperative deaths. Approximately a quarter of responders denied hands-on training in models or visit to training centers.

CONCLUSION

ESD appears to be practiced throughout the country, not only in tertiary or academic institutions and mainly in private practice. Most operators received limited training and still are at the beginning of their learning curve. The reported adverse events and mortality rates appear to be higher than Eastern reports.

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

Background

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

Methods

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

Results

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

Conclusions

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

Ex vivo porcine model study on the treatment outcomes of scissor-type knife versus needle-type knife in endoscopic submucosal dissection performed by trainees

Background

Endoscopic submucosal dissection (ESD) for gastrointestinal neoplasms can be technically difficult for trainee endoscopists. Presently, there is no consensus for trainees to select the endo-knife type in ESD. Therefore, we conducted a comparison study of treatment outcomes between scissors-type and needle-type knives in ESD performed by trainees in an ex vivo porcine model.

Methods

This study was conducted on trainee endoscopists who participated in ESD hands-on seminars held in August 2018 and September 2019. A total of 22 trainees from 13 institutions were divided into two groups according to their endoscopic experience. Under expert supervision, each trainee performed two ESDs in porcine models, namely, scissor-type knife (ESD-S) and needle-type knife (ESD-N). The efficacy and safety, including the procedure time and rates of self-completion, en bloc resection, and complications, were compared between ESD-S and ESD-N. In subgroup analysis, we also investigated the predictors associated with the difficulty of ESD for trainees using multivariate logistic regression analysis.

Results

Eight trainees had an experience of over 1000 endoscopies (senior trainee: S-Trainee), whereas the others had an experience of less than 1000 endoscopies (junior trainee: J-Trainee). Among the S-Trainees, no significant differences were observed in any treatment outcome between ESD-S and ESD-N. Among the J-Trainees, the total procedure and mucosal incision times were significantly shorter in ESD-S than in ESD-N [total procedure time: 16.5 min (range 10.0–31.0) vs. 22.3 min (range 10.0–38.0), P = 0.018; circumferential incision time: 10.0 min (range 6–16) vs. 17.0 min (range 5.0–31.5); P = 0.019]. Regarding complications, muscular injury occurred in two patients during ESD-N performed by J-Trainees; however, no muscular injury occurred during ESD-S. In subgroup analysis, ESD-N was an independent predictive factor of difficult ESD (odds ratio 5.28, 95% confidence interval 1.25–22.30; P = 0.024).

Conclusions

This study revealed that trainees, particularly those who have experienced less than 1000 endoscopies, should opt for the scissor-type knife to perform ESD.

Feedback from artificial intelligence improved the learning of junior endoscopists on histology prediction of gastric lesions

Background and study aims  Artificial intelligence (AI)-assisted image classification has been shown to have high accuracy on endoscopic diagnosis. We evaluated the potential effects of use of an AI-assisted image classifier on training of junior endoscopists for histological prediction of gastric lesions. Methods  An AI image classifier was built on a convolutional neural network with five convolutional layers and three fully connected layers A Resnet backbone was trained by 2,000 non-magnified endoscopic gastric images. The independent validation set consisted of another 1,000 endoscopic images from 100 gastric lesions. The first part of the validation set was reviewed by six junior endoscopists and the prediction of AI was then disclosed to three of them (Group A) while the remaining three (Group B) were not provided this information. All endoscopists reviewed the second part of the validation set independently. Results  The overall accuracy of AI was 91.0 % (95 % CI: 89.2-92.7 %) with 97.1 % sensitivity (95 % CI: 95.6-98.7%), 85.9 % specificity (95 % CI: 83.0-88.4 %) and 0.91 area under the ROC (AUROC) (95 % CI: 0.89-0.93). AI was superior to all junior endoscopists in accuracy and AUROC in both validation sets. The performance of Group A endoscopists but not Group B endoscopists improved on the second validation set (accuracy 69.3 % to 74.7 %; P  = 0.003). Conclusion  The trained AI image classifier can accurately predict presence of neoplastic component of gastric lesions. Feedback from the AI image classifier can also hasten the learning curve of junior endoscopists in predicting histology of gastric lesions.

Early gastric cancer with ball valve syndrome treated by endoscopic submucosal dissection

An 84-year-old woman with pneumonia, congestive heart failure and chronic renal failure presented for iron-deficiency anemia and appetite loss. Esophagogastroduodenoscopy revealed a 60-mm sub-pedunculated tumor arising from the antrum of the stomach. The tumor was friable, with bleeding, and prolapsed into the duodenal bulb, the ball valve syndrome. The tumor was considered the cause of the anemia and appetite loss. Attempted endoscopic reduction of the prolapsing tumor was unsuccessful, but the base of its stalk could be identified through the transparent hood; thus, we removed the tumor with endoscopic submucosal dissection. The tumor was retrieved successfully, and pathohistological examination revealed the tumor to be a well-differentiated adenocarcinoma. This case suggests that endoscopic submucosal dissection is useful as an alternative to surgery for removal of gastric tumors that have prolapsed into the duodenal bulb when polypectomy was difficult, but provided the tumor's attachment site can be identified endoscopically.

Preclinical evaluation of a novel thermally sensitive co-polymer (LiftUp) for endoscopic resection

Introduction: Endoscopic resection techniques can successfully resect large lesions either in "en bloc" fashion or in "piece-meal" technique by using a submucosal injection solution. The aim of this study was to evaluate the safety of a novel injectable, containing thermally sensitive co-polymer from ethylenoxide and propylenoxide (LiftUp) used as submucosal injection solution.Material and methods: We conducted an in vivo animal trial in the porcine model to evaluate the LiftUp gel in a preclinical setting and to study the effectiveness of mucosal lifting and the safety of the new injectable. In seven animals a total of 63 injections and endoscopic resections were carried out in different anatomical locations (esophagus, stomach and rectum). The resection sites were controlled endoscopically one and four weeks after resection and a histopathological evaluation of the resection sites was performed after four weeks.Results: The application of LiftUp was safe and there were no negative effects on wound healing after injection and resection. A major procedural complication rate (defined as perforation and major haemorrhage) of 3.2% was registered, which undercuts the anticipated mean complication rate of 4-8%. Furthermore, there was no necessity of reinjection after the initial submucosal injection in 90.5% and no procedural complications in 98.8%. The histopathological examination of the tissue samples indicated normal wound healing with granulation tissue and epithelialisation.Conclusion: The use of LiftUp as submucosal injection solution was feasible for different endoscopic resection techniques, with high and long-lasting elevation and fewer procedural adverse events than expected at trial planning. The new injectable is a practical advancement over the current state-of-the-art of submucosal injection and could fasten up the resection procedure and make endoscopic 'en bloc' resection safer.

Quality in upper gastrointestinal endoscopic submucosal dissection

Progress in the endoscopy technology field led to an increase in the diagnosis of early gastrointestinal (GI) superficial lesions and to an improvement of their treatment. Endoscopic submucosal dissection (ESD) has been developed in Japan with the aim of removing such lesions in one piece, in order to obtain a curative resection and to minimize the risk of local recurrence, and to preserve the native organ. ESD is widely used in Asia for the treatment of early upper and lower GI lesions and is currently gaining attention in Western countries too. However, ESD can be safely performed only by expert endoscopists and in specific clinical settings. Therefore, prior to decide whether ESD is feasible or not, the target lesion must be carefully assessed, in order to understand whether or not it is eligible for submucosal dissection. The aim of this paper is to review indications, limitations and technical aspects of upper GI ESD.

Endoscopic Submucosal Dissection of Early Gastric Cancer in Patients with Liver Cirrhosis

BACKGROUND AND OBJECTIVES

Endoscopic submucosal dissection (ESD) has become widely accepted method for treating early gastric cancer (EGC), but little is known about its role in patients with liver cirrhosis (LC). The aims of this study were to evaluate the outcomes of ESD in treating EGC in patients with LC.

METHODS

The multicenter retrospective study identified 43 patients with chronic hepatitis B (CHB)-related cirrhosis undergoing ESD for treating EGC. The patients (LC group) were subdivided into two groups based on their Child-Pugh classification (CP-class): 32 with CP-class A (LC-A) and 11 with CP-class B (LC-B). The patients were compared to 47 non-cirrhotic CHB patients who underwent ESD (CHB group). Eight patients had a past history of hepatocellular carcinoma (HCC) prior to ESD, but no patients had viable HCC when ESD was performed.

RESULTS

Procedural outcomes (en bloc, lateral/basal margins resection) and post-procedural complications (bleeding or perforation) did not differ significantly between the LC and CHB groups or between the LC-A and LC-B groups. No patients experienced worsening of the Child-Pugh score 1 month after ESD compared with the baseline score. During a median observation period of 66 months, the recurrence rates of gastric cancers were similar between the LC and CHB groups (5-year recurrence rates: 2.4 vs. 2.3%, p = 0.925), and all recurrent gastric cancers were completely resected by additional ESD. The overall mortality rate was increased in the LC group (5-year mortality rates: 17.9 vs. 5.7%, p = 0.034), and 8 of 10 deaths were attributed to liver-related diseases (such as HCC, complications of portal hypertension, hepatic failure).

CONCLUSIONS

ESD is feasible in patients with EGC and comorbid LC, even those with CP-class B cirrhosis. Their prognosis depends on LC-related diseases and not recurrent EGC.

Early Gastric Cancer: Clinical Behavior and Treatment Options. Results of an Italian Multicenter Study on Behalf of the Italian Gastric Cancer Research Group (GIRCG)

BACKGROUND

Early gastric cancer (EGC) generally has a good prognosis. However, the current definition of EGC includes various subgroups of patients with different pathological characteristics and different prognoses, some of whom have aggressive disease with a biological behavior similar to that of advanced carcinoma.

MATERIALS AND METHODS

We retrospectively evaluated 1,074 patients with EGC who had undergone surgery between 1982 and 2009. The cumulative incidence function of cancer-specific mortality and competing mortality were estimated using the Fine and Gray method.

RESULTS

The median follow-up period was 193 months (range 1-324). Five hundred and sixty-two (52.3%) patients died, 96 (8.9%) from EGC. The 5-, 10-, and 15-year cumulative incidence rates for mortality of all causes were 20.5% (95% confidence interval [CI] 18.0-22.9), 37.1% (95% CI 34.7-40.7), and 52.6% (95% CI 49.1-56.0), respectively; for cancer-specific mortality, 6.0% (95% CI 4.5-7.6), 9.9% (95% CI 7.9-11.9), and 11.1% (95% CI 8.8-13.3), respectively; and for mortality of other causes, 14.4% (95% CI 12.1-16.6), 27.2% (95% CI 24.2-30.2), and 41.5% (95% CI 38.1-43.3), respectively. A significant increase in the risk of cancer-specific mortality was observed for lesions >2 cm (adjusted hazard ratio [HR] = 1.44, 95% CI 1.07-1.94), Pen A-type disease (adjusted HR = 1.73, 95% CI 1.15-2.61), and node-positive cancers (adjusted HR = 2.28, 95% CI 1.61-3.21).

CONCLUSION

Patients with EGC with tumors >2 cm, Pen A-type disease according to Kodama, or lymph node metastases show a poorer prognosis and an increased risk of cancer-specific mortality.

IMPLICATIONS FOR PRACTICE

Early gastric cancer generally has a good prognosis, and some patients can be treated radically by endoscopic resection. However, the current definition of early gastric cancer includes subgroups of patients with an aggressive disease. In particular, patients with lymph node metastases and Pen A-type tumors according to Kodama's classification need a more invasive treatment, such as subtotal or total gastrectomy with an extended D2 lymphadenectomy, plus eventual adjuvant chemotherapy.

Experience in colon sparing surgery in North America: advanced endoscopic approaches for complex colorectal lesions

BACKGROUND

Need for colon sparing interventions for premalignant lesions not amenable to conventional endoscopic excision has stimulated interest in advanced endoscopic approaches. The aim of this study was to report a single institution's experience with these techniques.

METHODS

A retrospective review was conducted of a prospectively collected database of all patients referred between 2011 and 2015 for colorectal resection of benign appearing deemed endoscopically unresectable by conventional endoscopic techniques. Patients were counseled for endoscopic submucosal dissection (ESD) with possible combined endoscopic-laparoscopic surgery (CELS) or alternatively colorectal resection if unable to resect endoscopically or suspicion for cancer. Lesion characteristic, resection rate, complications, and outcomes were evaluated.

RESULTS

110 patients were analyzed [mean age 64 years, female gender 55 (50%), median body mass index 29.4 kg/m²]. Indications for interventions were large polyp median endoscopic size 3 cm (range 1.5-6.5) and/or difficult location [cecum (34.9%), ascending colon (22.7%), transverse colon (14.5%), hepatic flexure (11.8%), descending colon (6.3%), sigmoid colon (3.6%), rectum (3.6%), and splenic flexure (2.6%)]. Lesion morphology was sessile (N = 98, 93%) and pedunculated (N = 12, 7%). Successful endoscopic resection rate was 88.2% (N = 97): ESD in 69 patients and CELS in 28 patients. Complication rate was 11.8% (13/110) [delayed bleeding (N = 4), perforation (N = 3), organ-space surgical site infection (SSI) (N = 2), superficial SSI (N = 1), and postoperative ileus (N = 3)]. Out of 110 patients, 13 patients (11.8%) required colectomy for technical failure (7 patients) or carcinoma (6 patients). During a median follow-up of 16 months (range 6-41 months), 2 patients had adenoma recurrence.

CONCLUSIONS

Advanced endoscopic surgery appears to be a safe and effective alternative to colectomy for patients with complex premalignant lesions deemed unresectable with conventional endoscopic techniques.

Is it possible to perform gastric endoscopic submucosal dissection without discontinuation of a single antiplatelet of thienopyridine derivatives?

BACKGROUND AND STUDY AIMS

Combined use of thienopyridine derivatives and other antithrombotic agents is reported to be a risk factor for postoperative bleeding after gastric endoscopic submucosal dissection (ESD). However, risk associated with a single thienopyridine derivative has not been evaluated. In this study, we aimed to evaluate bleeding risks of gastric ESD without discontinuation of a single thienopyridine derivative agent.

PATIENTS AND METHODS

 This multicenter, prospective, observational cohort study included patients who had undergone implantation of a coronary artery stent and who were taking a combination of aspirin antiplatelet therapy and a thienopyridine derivative agent. Enrolled patients discontinued aspirin and underwent gastric ESD without the discontinuation of a single thienopyridine derivative agent. The primary endpoint was the major bleeding complication rate after gastric ESD.

RESULTS

 Eleven patients were enrolled in this study from April 2015 to November 2016 after written informed consent was obtained. Among them, 1 patient, who had undergone surgery for a primary cardiac tumor before ESD, was excluded from the study. Ten patients underwent gastric ESD for neoplasms. En-bloc resections were achieved in all cases without intraoperative bleeding complications. Two patients experienced postoperative bleeding although neither case required a blood transfusion (95 % CI 2.5 - 55.6 %).

CONCLUSION

 En-bloc resections were possible although the postoperative bleeding rate tended to be higher in gastric ESD without discontinuation of a single thienopyridine derivative agent. Additional preventive measures are mandatory to carry out safe gastric ESD in such settings.

Antral or Pyloric Deformity Is a Risk Factor for the Development of Postendoscopic Submucosal Dissection Pyloric Strictures

BACKGROUND/AIMS

Surgeons must be aware of risk factors for strictures before performing endoscopic submucosal dissection (ESD), to enable early interventions to prevent severe strictures.

METHODS

This study was a single-center retrospective study. We reviewed the clinical data of patients who has undergone gastric ESD from January 2007 to December 2012.

RESULTS

Among the 3,819 patients who had undergone gastric ESD, 11 patients (7.2%) developed pyloric strictures and received successful endoscopic balloon dilation. Significant differences were noted between the patients without and with post-ESD strictures for pretreatment of antral or pyloric deformities (46.4% vs 81.8%), the proportion of extension to the lumen circumference (>3/4, 9.4% vs 54.5%), the longitudinal extent of mucosal defects (27.9±10.1 mm vs 51.5±10.8 mm), and post-ESD bleeding (2.9% vs 27.3%). Multivariate analysis revealed that pretreatment antral or pyloric deformities (odds ratio [OR], 30.53; 95% confidence interval [CI], 1.476 to 631.565; p=0.027), larger longitudinal extent of mucosal defects (OR, 1.20; 95% CI, 1.074 to 1.340; p=0.001), and circumferential extension of ≥3/4 (OR, 13.69; 95% CI, 1.583 to 118.387; p=0.017) were independent risk factors for post-ESD stricture.

CONCLUSIONS

Antral or pyloric deformities, sub-circumferential resection over more than 75% of the circumference and greater longitudinal extent of mucosal defects are independent risk factors for post-ESD stricture.

History and Development of Accessories for Endoscopic Submucosal Dissection

Endoscopic submucosal dissection (ESD) procedure is composed of circumferential mucosal incision and submucosal dissection. A variety of endoscopic accessories are required to perform mucosal incision and submucosal dissection safely. As a result of the improvements in ESD devices and peripheral equipment and development of the ESD technique, ESD procedures have been performed extensively worldwide. Here I review the history of the development of accessories used in performing ESD procedures.

Magnetic anchor guidance for endoscopic submucosal dissection and other endoscopic procedures

Endoscopic submucosal dissection (ESD) is a well-established, minimally invasive treatment for superficial neoplasms of the gastrointestinal tract. The universal adoption of ESD has been limited by its slow learning curve, long procedure times, and high risk of complications. One technical challenge is the lack of a second hand that can provide traction, as in conventional surgery. Reliable tissue retraction that exposes the submucosal plane of dissection would allow for safer and more efficient dissection. Magnetic anchor guided endoscopic submucosal dissection (MAG-ESD) has potential benefits compared to other current traction methods. MAG-ESD offers dynamic tissue retraction independent of the endoscope mimicking a surgeon’s “second hand”. Two types of magnets can be used: electromagnets and permanent magnets. In this article we review the MAG-ESD technology, published work and studies of magnets in ESD. We also review the use of magnetic anchor guidance systems in natural orifice transluminal endoscopic surgery and the idea of magnetic non-contact retraction using surface ferromagentization. We discuss the current limitations, the future potential of MAG-ESD and the developments needed for adoption of this technology.

Traction using a clip-with-line is a preferred method for trainees in performing esophageal endoscopic submucosal dissection: an animal model study

BACKGROUND

The optimal operative process of esophageal endoscopic submucosal dissection (ESD), especially for the beginners, is not established. In this study, the clip-with-line method, the tunneling method and the conventional method for esophageal ESD were compared in a training course on live pigs.

METHODS

15 trainee endoscopists were randomized into three groups, the clip-with-line method group, the tunneling method group, and the conventional method group. Each trainee performed four esophageal ESDs on live pigs with one of the specified methods, assisted by a senior endoscopist. The procedural time and speed, the en bloc resection rates, adverse events, and self-completion rates were recorded, and learning curves were drawn.

RESULTS

The procedural time in the clip-with-line group was significantly shorter than those in the tunneling and the conventional method group (47.4 ± 9.0 min versus 67.0 ± 15.1 min and 67.0 ± 11.8 min, p = 0.000). The clip-with-line method had the lowest rates of perforation and muscle layer injury among the three methods. The en bloc resection rates and self-completion rates were similar among the three groups. Learning curves analysis showed the clip-with-line method was the easiest one for the trainees to master.

CONCLUSIONS

The clip-with-line method shortened procedural time for trainees, and was associated with lower rates of adverse events. This method is preferred for endoscopists in their learning periods for esophageal ESD.

Incidence and impact of scheduled endoscopic surveillance on recurrence after curative endoscopic resection for early gastric cancer

BACKGROUND AND AIMS

The aim of this study was to identify the incidence of recurrent lesions after endoscopic submucosal dissection (ESD) and to determine whether scheduled endoscopic surveillance might control their development and treatment.

METHODS

We reviewed the clinical data of patients who underwent gastric ESD between March 2007 and April 2014.

RESULTS

A total of 1347 patients who underwent curative ESD for early gastric cancer that met the expanded indication for ESD were analyzed. Of these, recurrence at the previous ESD site occurred in 39 patients, whereas recurrence in the stomach at a site other than the ESD site occurred in 102 patients. Older age, intestinal metaplasia, flat or depressed lesions, and ESD criteria were associated with recurrence in the stomach in places other than the ESD site. The annual incidence was .84% for recurrence at the previous ESD site and 2.48% for recurrence in the stomach at other than the ESD site. In cases of local recurrence and metachronous lesions, there was a significant difference between the short- and long-surveillance interval group (≤12 months vs >12 months) in the proportions of recurrent adenocarcinoma (31.9% vs 60.9%, P = .021), additional gastrectomy (7.1% vs 46.2%, P = .033), and size (8.92 ± 4.17 mm vs 18.08 ± 10.47 mm, P = .010).

CONCLUSIONS

Scheduled endoscopy surveillance is necessary for detecting recurrent lesions. In addition, scheduled endoscopy surveillance might help to detect recurrent lesions at a stage early enough for a curative resection.

A novel artificial tissue simulator for endoscopic submucosal resection training - a pilot study

Background

We developed a novel artificial simulator for endoscopic submucosal dissection (ESD) as a bridge between instructional videos and animal tissue training and aimed to evaluate the feasibility of using an artificial tissue model in ESD training.

Methods

Eight gastroenterology fellows from one medical center were enrolled in this ESD training program. Before and after the simulator training, attendees indicated on a 5-point scale the degree of difficulty in performing the following procedures: lesion marking, mucosal pre-cutting, circumferential incision, submucosal dissection, and hemostasis. After the simulator training, the participants completed a questionnaire regarding their opinions on the degree of realism and the feasibility of using this model for training.

Results

After watching an instructional video, attendees felt that the most difficult techniques were submucosal dissection and hemostasis. After using the artificial tissue simulator model, the attendees felt more confident in performing performing lesion marking (p = 0.026) and submucosal dissection (p = 0.037). However, they still felt that hemostasis was the most difficult techniques to master. Overall, the attendees thought the simulator was realistic in simulated lesion marking and its use was feasible for simulated lesion marking and submucosal dissection.

Conclusion

Our pilot study shows the feasibility of using a novel artificial tissue in performing ESD and we believe that the artificial tissue simulator acts well as a bridge between instructional videos and animal model training. The model is reusable and inexpensive, and could disseminate the techniques of the ESD more easily and quickly.

Endoscopic Submucosal Dissection (ESD) and Related Techniques as Precursors of "New Notes" Resection Methods for Gastric Neoplasms

Endoscopic full-thickness resection for subepithelial tumors is one of the more attractive proposed methods for less-invasive transluminal surgery but remains challenging in terms of safety and feasibility. Currently, laparoscopic endoscopic cooperative surgery is thought to be a more clinically acceptable approach. In targeting cancers, however, more advanced nonexposure techniques are required to avoid the risk of iatrogenic tumor seeding. By combining these techniques with possible regional lymphadenectomy using sentinel node navigation surgery, an ideal minimally invasive, function-preserving gastric resection can be achieved even in possible node-positive cancers. Further development for this type of advanced endoscopic surgery is expected.

Efficacy of endoscopic mucosal resections for the management of small gastric adenomas with low-grade dysplasia

OBJECTIVE

Gastric adenoma with low-grade dysplasia (LGD) can progress to gastric cancer; however, the optimal therapeutic modality for LGD has not been established. The aim of this study was to assess the efficacy, safety of and local recurrence following endoscopic mucosal resection (EMR) for LGD. Specifically, we compared EMR with circumferential precutting (EMR-P) and EMR using a dual-channel endoscope (EMR-D) for the treatment of LGD ≤2 cm.

MATERIALS AND METHODS

A total of 158 lesions from 147 patients with LGD treated by EMR were retrospectively analyzed. The en bloc resection rate, complete resection rate, procedure time, complication rate and local recurrence rate were compared between EMR-P and EMR-D.

RESULTS

The en bloc resection and complete resection rates of EMR were 91.1% and 90.5%, respectively. The bleeding and perforation rates were 1.3% and 1.3%, respectively. The local recurrence rate following EMR was 2.2%. The en bloc resection and complete resection rates did not differ between EMR-P and EMR-D (88.2% vs. 92.5%, p = not significant (NS); and 90.2% vs. 90.7%, p = NS, respectively). The procedure time was significantly longer for EMR-P compared with EMR-D (16 (5-141) vs. 7 (2-48) min, p < 0.001), and the complication rate was significantly higher for EMR-P (7.8% vs. 0.0%, p = 0.010). Local recurrence was not found in EMR-P, whereas the recurrence rate was 3.2% in EMR-D.

CONCLUSION

EMR is an effective method for the treatment of LGD ≤2 cm. Compared with EMR-P, EMR-D appears to be the more effective, technically simple and safer method.

Upgrading the definition of early gastric cancer: better staging means more appropriate treatment

Since Murakami defined early gastric cancer (EGC) as a "carcinoma limited to the gastric mucosa and/or submucosa regardless of the lymph node status", several authors have focused on the most influential histopathological parameters for predicting the development of lymph node metastases by considering the lymph node status as an important prognostic factor. A few authors have also considered the depth of invasion as one of the keys to explaining the existence of subgroups of patients affected by EGC with poor prognoses. In any case, EGC is still considered an initial phase of tumor progression with good prognosis. The introduction of modern endoscopic devices has allowed a precise diagnosis of early lesions, which can lead to improved definitions of tumors that can be radically treated with endoscopic mucosal resection or endoscopic submucosal dissection (ESD). Given the widespread use of these techniques, the Japanese Gastric Cancer Association (JGCA) identified in 2011 the standard criteria that should exclude the presence of lymph node metastases. At that time, EGCs with nodal involvement should have been asserted as no longer fitting the definition of an early tumor. Some authors have also demonstrated that the morphological growth pattern of a tumor, according to Kodama's classification, is one of the most important prognostic factors, thereby suggesting the need to report it in histopathological drafts. Notwithstanding the acquired knowledge regarding the clinical behavior of EGC, Murakami's definition is still being used. This definition needs to be upgraded according to the modern staging of the disease so that the appropriate treatment would be selected.

Endoscopic Submucosal Dissection for Early Gastric Cancer: Getting It Right!

Endoscopic resection is a widely accepted less-invasive treatment technique for local resection of early gastric cancer (EGC) lesions with a negligible risk of lymph node metastasis. Remarkable progress has been made during the last decade in this field, both in terms of expansion of the indications (to larger lesions and to lesions with ulceration) and in terms of technical improvements from endoscopic mucosal resection (EMR) to endoscopic submucosal dissection (ESD). Previously, larger lesions and lesions with ulceration were resected surgically because of the difficulty in effectively using EMR in this context. ESD however allows a high rate of en bloc resections, regardless of tumor location, tumor size, or the presence of ulceration. Nonetheless, ESD also has drawbacks: the procedure time is increased, ESD is more technically challenging compared to EMR, and, finally, ESD is associated with a slightly higher risk of complications. In order to overcome these limitations and minimize complications, a step-by-step process is important for learning ESD techniques. This chapter addresses the indications, results, some technical tips, and complications of ESD for EGC.

Ex vivo comparison study of smart Shooter®, a new endoscopic device for safe and speedy treatment

BACKGROUND

In many endoscopic procedures, the operative view can be compromised when manipulating the treatment device because the endoscopists must release their hand from the endoscope. We have developed a new device called the Smart Shooter® (SS) for simultaneous manipulation of the endoscope and treatment device, and evaluated the utility of the SS compared with the conventional method.

METHODS

The SS is a semirigid, loop-shaped channel extender that enables endoscopists to manipulate the treatment device with the thumb of the right hand while holding the endoscope with the same hand. We conducted a comparative study of gastric endoscopic submucosal dissection (ESD) and esophageal injection sclerotherapy (EIS) in a porcine model to compare the utility of the SS method with the conventional method.

RESULTS

In gastric ESD, all lesions were resected en bloc with no perforation. The mean operative time was significantly shorter with the SS method than with the conventional method (287.5 ± 155.4 vs. 403.5 ± 215.6 s, p = 0.04). In esophageal EIS, 4 paravenous injections were given with the SS method and 5 were given using the conventional method. Similarly, the mean operative time was significantly shorter with the SS method than with the conventional method (19.0 ± 7.8 vs. 23.8 ± 10.0 s, p = 0.04).

CONCLUSION

Use of the SS enabled a shorter operative time for gastric ESD and esophageal EIS with no adverse events. The present results suggest that the SS can contribute to safe and speedy endoscopic treatment.

A multicenter study of using carbon nanoparticles to show sentinel lymph nodes in early gastric cancer

BACKGROUND

Lymph node metastasis occurs in approximately 10% of early gastric cancer. Preoperative or intra-operative identification of lymph node metastasis in early gastric cancer is crucial for surgical planning. The purpose of this study was to evaluate the feasibility of using carbon nanoparticles to show sentinel lymph nodes (SLNs) in early gastric cancer.

METHODS

A multicenter study was performed between July 2012 and November 2014. Ninety-one patients with early gastric cancer identified by preoperative endoscopic ultrasonography were recruited. One milliliter carbon nanoparticles suspension, which is approved by Chinese Food and Drug Administration, was endoscopically injected into the submucosal layer at four points around the site of the primary tumor 6-12 h before surgery. Laparoscopic radical resection with D2 lymphadenectomy was performed. SLNs were defined as nodes that were black-dyed by carbon nanoparticles in greater omentum and lesser omentum near gastric cancer. Lymph node status and SLNs accuracy were confirmed by pathological analysis.

RESULTS

All patients had black-dyed SLNs lying in greater omentum and/or lesser omentum. SLNs were easily found under laparoscopy. The mean number of SLNs was 4 (range 1-9). Carbon nanoparticles were around cancer in specimen. After pathological analysis, 10 patients (10.99%) had lymph node metastasis in 91 patients with early gastric cancer. SLNs were positive in 9 cases and negative in 82 cases. In pathology, carbon nanoparticles were seen in lymphatic vessels, lymphoid sinus, and macrophages in SLNs. When SLNs were positive, cancer cells were seen in lymph nodes. The sensitivity, specificity, and accuracy of black-dyed SLNs in early gastric cancers were 90, 100, and 98.9 %, respectively. No patient had any side effects of carbon nanoparticles in this study.

CONCLUSIONS

It is feasible to use carbon nanoparticles to show SLNs in early gastric cancer. Carbon nanoparticles suspension is safe for submucosal injection.

Indications and Techniques for Endoscopic Submucosal Dissection

Endoscopic submucosal dissection (ESD) allows for curative resection of superficial neoplasms of the gastrointestinal tract. Although ESD is the standard of care in Japan, its adoption in the West has been slow. Recent studies have shown the advantages of ESD over endoscopic mucosal resection, and as many of the barriers to ESD have been overcome, we are seeing an increasing interest in this technique. ESD can be used to treat superficial gastric, esophageal, and colorectal lesions. The most important pre-procedure step is estimating the depth of invasion of a lesion and by proxy the risk of lymph node metastasis. After a lesion has been resected, the histopathological analysis will determine whether the resection was curative or whether further surgery is needed. In conclusion, ESD is being more widely used in the West, and it is important to understand the indications, limitations, and techniques of ESD.

Impact of formal training in endoscopic submucosal dissection for early gastrointestinal cancer: A systematic review and a meta-analysis

AIM: To summarize the clinical impact of a formal training for the effectiveness and safety of endoscopic submucosal dissection for gastrointestinal cancer.

METHODS: We searched databases including PubMed, EMBASE and the Cochrane Library and Science citation Index updated to August 2014 to include eligible articles. In the Meta-analysis, the main outcome measurements were en bloc resection rate, local recurrence rate (R0) and the incidence of procedure-related complications (perforation, bleeding).

RESULTS: En bloc resection was high for both, dissecting stomach tumors with an overall percentage of 93.2% (95%CI: 90.5-95.8) and dissecting colorectal tumors with an overall percentage of 89.4% (95%CI: 85.1-93.7). Although the number of studies reporting R0 resection (the dissected specimen was revealed free of tumor in both vertical and lateral margins) was small, the overall estimates for R0 resection were 81.4% (95%CI: 72-90.8) for stomach and 85.9% (95%CI: 77.5-95.5) for colorectal tumors, respectively. The analysis showed that the percentage of immediate perforation and bleeding were very low; 4.96 (95%CI: 3.6-6.3) and 1.4% (95%CI: 0.8-1.9) for colorectal tumors and 3.1% (95%CI: 2.0-4.1) and 4.8% (95%CI: 2.8-6.7) for stomach tumors, respectively.

CONCLUSION: In order to obtain the same rate of success of the analyzed studies it is a necessity to create training centers in the western countries during the “several years” of gastroenterology residence first only to teach EGC diagnose and second only to train endoscopic submucosal dissection.

Redefining early gastric cancer

BACKGROUND

The problem is that current definitions of early gastric cancer allow the inclusion of regional lymph node metastases. The increasing use of endoscopic submucosal dissection to treat early gastric cancer is a concern because regional lymph nodes are not addressed. The aim of the study was thus to critically evaluate current evidence with regard to tumour-specific factors associated with lymph node metastases in "early gastric cancer" to develop a more precise definition and improve clinical management.

METHODS

A systematic and comprehensive search of major reference databases (MEDLINE, EMBASE, PubMed and the Cochrane Library) was undertaken using a combination of text words "early gastric cancer", "lymph node metastasis", "factors", "endoscopy", "surgery", "lymphadenectomy" "mucosa", "submucosa", "lymphovascular invasion", "differentiated", "undifferentiated" and "ulcer". All available publications that described tumour-related factors associated with lymph node metastases in early gastric cancer were included.

RESULTS

The initial search yielded 1494 studies, of which 42 studies were included in the final analysis. Over time, the definition of early gastric cancer has broadened and the indications for endoscopic treatment have widened. The mean frequency of lymph node metastases increased on the basis of depth of infiltration (mucosa 6% vs. submucosa 28%), presence of lymphovascular invasion (absence 9% vs. presence 53%), tumour differentiation (differentiated 13% vs. undifferentiated 34%) and macroscopic type (elevated 13% vs. flat 26%) and tumour diameter (≤2 cm 8% vs. >2 cm 25%).

CONCLUSION

There is a need to re-examine the diagnosis and staging of early gastric cancer to ensure that patients with one or more identifiable risk factor for lymph node metastases are not denied appropriate chemotherapy and surgical resection.

Endoscopic submucosal dissection in gastric lesions: the 100 cases experience from a tertiary reference center in West

OBJECTIVE

Endoscopic submucosal dissection (ESD) is an endoscopic treatment method widely used in premalignant and malignant lesions in countries of the Far East. This method, which is difficult technically and has a high complication risk rate, has rarely been performed in the West, because of the fewer number of upper gastrointestinal lesions. In the present study, we aimed to present our results of gastric ESD procedures in respect to the learning curve.

METHODS

A total of 100 ESD procedures, which were performed in the stomach between April 2012 and September 2014, were recorded prospectively before and after the procedure. Patient data were analyzed retrospectively. ESD procedures were numbered chronologically; the first 30 patients constituted group 1, whereas the rest were classified as the group 2. ESD results were compared between the groups.

RESULTS

In a total of 95 patients, 100 gastric ESDs were performed. The overall en-bloc and complete resection rates were 93% and 92%, respectively. In respect of the learning curve, there were significant differences in the sizes of lesions and tissues obtained, procedure duration and dissection rate, snare use and knife preferences between groups (p = 0.002, p < 0.001, p = 0.003, p < 0.001, p = 0.009, and p < 0.001, respectively). No significant difference was detected in the en-bloc and complete resection rates and complications between the groups.

CONCLUSION

According to guideline recommendations and masters for ESD, if ESD training is initiated and continued, successful ESD may be performed in localized lesions in the stomach.

Endoscopic full-thickness resection for gastric submucosal tumors arising from the muscularis propria layer

AIM: To evaluate the efficacy, safety and feasibility of endoscopic full-thickness resection (EFR) for the treatment of gastric submucosal tumors (SMTs) arising from the muscularis propria.

METHODS: A total of 35 gastric SMTs arising from the muscularis propria layer were resected by EFR between January 2010 and September 2013. EFR consists of five major steps: injecting normal saline into the submucosa; pre-cutting the mucosal and submucosal layers around the lesion; making a circumferential incision as deep as the muscularis propria around the lesion using endoscopic submucosal dissection and an incision into the serosal layer around the lesion with a Hook knife; a full-thickness resection of the tumor, including the serosal layer with a Hook or IT knife; and closing the gastric wall with metallic clips.

RESULTS: Of the 35 gastric SMTs, 14 were located at the fundus, and 21 at the corpus. EFR removed all of the SMTs successfully, and the complete resection rate was 100%. The mean operation time was 90 min (60-155 min), the mean hospitalization time was 6.0 d (4-10 d), and the mean tumor size was 2.8 cm (2.0-4.5 cm). Pathological examination confirmed the presence of gastric stromal tumors in 25 patients, leiomyomas in 7 and gastric autonomous nerve tumors in 2. No gastric bleeding, peritonitis or abdominal abscess occurred after EFR. Postoperative contrast roentgenography on the third day detected no contrast extravasation into the abdominal cavity. The mean follow-up period was 6 mo, with no lesion residue or recurrence noted.

CONCLUSION: EFR is efficacious, safe and minimally invasive for patients with gastric SMTs arising from the muscularis propria layer. This technique is able to resect deep gastric lesions while providing precise pathological information about the lesion. With the development of EFR, the indications of endoscopic resection might be extended.