Endoscopic submucosal dissection in the upper gastrointestinal tract: present and future view of Europe

A scoring system to predict the technical difficulty of endoscopic resection for cardial submucosal tumors

BACKGROUND AND AIM

Endoscopic resection has been successfully used for the removal of digestive submucosal tumors (SMTs). However, the cardia has been considered a challenging location for endoscopic resection due to its narrow lumen and sharp angle. The objective of this study was to establish a clinical scoring model to grade the technical difficulty of endoscopic resection for cardial SMTs.

METHODS

A total of 246 patients who suffered cardial SMTs and received endoscopic resection were included in this retrospective study. All of them were randomized into the training cohort (n = 123) or internal validation cohort (n = 123). Potential predictors were analyzed using univariate analysis. Then, covariates with P < 0.05 were selected for the multivariate logistic regression model. The β coefficients from the logistic regression model were used to create a scoring system for technical difficulty prediction by rounding the score to the nearest integer of the absolute β coefficient value.

RESULTS

The clinical score consisted of the following factors: male gender (2 points), extraluminal growth (3 points), and maximum diameter ≥3 cm (3 points). The scoring model demonstrated good discriminatory power, with an area under the receiver operating characteristic curve of 0.860 and a 95% confidence interval of 0.763-0.958. The model also showed a good goodness of fit in the Hosmer-Lemeshow test (P = 0.979). In the training cohort, the probability of encountering technical difficulty in the easy (score = 0), intermediate (score = 1-3), difficult (score = 4-6), and very difficult (score >6) categories was 0, 6.8%, 33.3%, and 100.0%, respectively; similarly, in the validation cohort, it was 0, 5.6%, 22.2%, and 50.0%, respectively.

CONCLUSIONS

This scoring system could serve as a valuable tool for clinicians in predicting the technical difficulty of endoscopic resection for cardial SMTs.

Muscular injury as an independent risk factor for esophageal stenosis after endoscopic submucosal dissection of esophageal squamous cell cancer

BACKGROUND AND AIMS

Stenosis after esophageal endoscopic submucosal dissection (ESD) has a high incidence, and muscular injury is an important risk factor for esophageal stenosis. Hence, this study aimed to classify muscular injury degrees and investigate their association with postoperative stenosis.

METHODS

This retrospective study included 1033 patients with esophageal mucosal lesions treated with ESD between August 2015 and March 2021. Demographic and clinical parameters were analyzed, and stenosis risk factors were identified using multivariate logistic regression. A novel muscular injury classification system was proposed and used to investigate the association between different muscular injury degrees and postoperative stenosis. Finally, a scoring system was established to predict muscular injury.

RESULTS

Of 1033 patients, 118 (11.4%) had esophageal stenosis. The multivariate analysis demonstrated that the history of endoscopic esophageal treatment, circumferential range, and muscular injury were significant risk factors for esophageal stenosis. Patients with type II muscular injuries tended to develop complex stenosis (n = 13 [36.1%], P < .05), and type II muscular injuries were more likely to predispose patients to severe stenosis than type I (73.3% and 92.3%, respectively). The scoring system showed that patients with high scores (3-6) were more likely to have muscular injury. The score model presented good discriminatory power in the internal validation (area under the receiver-operating characteristic curve, .706; 95% confidence interval, .645-.767) and goodness-of-fit in the Hosmer-Lemeshow test (P = .865).

CONCLUSIONS

Muscular injury was an independent risk factor for esophageal stenosis. The scoring system demonstrated good performance in predicting muscular injury during ESD.

Associated risk factor analysis and the prognostic impact of positive resection margins after endoscopic resection in early esophageal squamous cell carcinoma

Endoscopic resection for early esophageal cancer has a risk of residual margins. The risk these residual margins pose have not been fully evaluated. The present study aimed to investigate the associated risk factors and prognosis of residual margins following the endoscopic resection of early esophageal squamous cell carcinoma. In total, 369 patients (381 lesions) with early esophageal squamous cell carcinoma treated in the Fourth Hospital of Hebei Medical University (Shijiazhuang, China) with endoscopic resection were retrospectively analyzed. Sex, age, location, tumor diameter, depth of tumor invasion, endoscopic treatment, endoscopic ultrasonography (EUS) before resection, work experience of endoscopists and the degree of tumor differentiation were all evaluated as potential risk factors. In addition, the prognosis of patients with positive margins were analyzed. A total of 73 patients (73/381, 19.2%) had positive margins after endoscopic resection. Amongst the 65 patients who were successfully followed up, five patients succumbed to cardiovascular and cerebrovascular diseases, one patient received radiotherapy, two patients received radiotherapy and chemotherapy whilst one patient received chemotherapy. By contrast, 12 patients received surgery and 20 patients received additional endoscopic mucosal resection or endoscopic submucosal dissection. The other 29 patients were followed up regularly and no recurrence could be found. Univariate analysis revealed that tumor diameter, endoscopic treatment, depth of invasion, EUS before resection, degree of tumor differentiation and direction of invasion were all associated with the positive margin. Multivariate logistic regression analysis then found that EUS before resection, degree of tumor differentiation and depth of tumor invasion are independent risk factors for positive margins after endoscopic resection. These results suggest that poorly differentiated lesions and deeper invasion depth can increase the risk of positive margin after endoscopic resection. As a result, EUS evaluation before resection may reduce the risk of invasion depth. In addition, for poorly differentiated lesions, more aggressive treatment regimens may be recommended for preventing recurrence.

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.

Endoscopic submucosal dissection: Italian national survey on current practices, training and outcomes

BACKGROUND AND AIMS

Most of the evidence supporting endoscopic submucosal dissection (ESD) comes from Asia. European data are primarily reported by specialized referral centers and thus may not be representative of common European ESD practice. The aim of this study is to understand the current state of ESD practice across Italian endoscopy centers.

METHODS

All Italian endoscopists who were known to perform ESD were invited to complete a structured questionnaire including: operator features and competencies, ESD training details and clinical outcomes over a 2-year period.

RESULTS

Twenty-nine operators from 23 centers (69% response rate) completed the questionnaire: 18 (62%) were <50 years old; 7 (24%) were female; 16 (70%) were located in Northern Italy. Overall ESD volume was <40 cases in 9 (31%) operators, 40-80 in 8 (27.5%), 80-150 in 4 (13.8%) and >150 in 8 (27.5%). Colorectal ESD was predominant for operators with an experience >80 cases. En-bloc resection rates ranged from 77.2 to 97.2% depending on the anatomic location with an R0 resection rate range of 75.3-93.6%. ESD perforation rates in the colon and rectum were significantly lower when experience was >150 compared to 80-150 cases (p < 0.0001 and p = 0.006 for colon and rectum, respectively).

CONCLUSION

ESD in Italy is performed by a significant number of operators. Overall, Italian endoscopists performing ESD have achieved a good competence level. However, there is much variability in training protocols, initial supervision of procedures, practice settings, case mix and procedural volume/year that are likely responsible for some of the suboptimal resectional outcomes and increased perforation risk, mainly in the colon. Standardized training programs, practice parameters and auditing of outcomes are required.

Long-term follow-up of endoscopic submucosal dissection of gastric dysplasia and early neoplasia in a United Kingdom Caucasian population - a tertiary centre experience

Introduction: Endoscopic submucosal dissection (ESD) is extensively performed for the treatment of early gastric cancer (EGC) in the Eastern countries due to its favourable outcomes compared to gastrectomy in terms of lower complication rates, shorter hospital stays, better quality of life, with similar 5-year survival rate. Yet, its use is still limited in the UK.Aim: A long-term follow-up study to evaluate the outcome of ESD in the treatment of EGC in a Caucasian population at a tertiary referral centre in the United Kingdom.Methods: Data for the 35 Caucasian patients, who underwent ESD in a tertiary referral centre between May 2012 and June 2017 were collected. The selected patients were followed-up until May 2018. Curative resection (CR) and survival rates were used to measure the efficacy of ESD.Results: ESD was attempted on 46 lesions and completed on 37. En-bloc and CR rates of 57% and 19% were achieved, respectively. 24% of the lesions were non-CR and 57% were indefinite for non-CR/CR and 41% of the lesions showed change in histological grade post-ESD. Complete reversal of dysplasia/neoplasia was seen in 60% of the 'indefinite' group and 100% of the CR group at latest FU (18 months, mean). Recurrence was seen in 23% of the patients at latest FU. Seventy-one months' survival rate was 77%, while the disease-specific mortality was 0%.Conclusions: This study demonstrates the positive long-term outcome of ESD for gastric neoplasia in a UK Caucasian population, encouraging further development and implementation of ESD in the UK.

Learning curve and clinical outcome of gastric endoscopic submucosal dissection performed by trainee operators

BACKGROUND

Although endoscopic submucosal dissection (ESD) represents a significant progress in therapeutic endoscopy, little is known about how trainees attain its technical proficiency. The aims of this study were to evaluate the learning curve and clinical outcomes of gastric ESD performed by trainee endoscopists.

METHODS

Between April 2009 and March 2014, 334 gastric ESD procedures were performed by seven trainees (42-50 consecutive cases per trainee). The learning curve for gastric ESD was evaluated using the cumulative sum (CUSUM) method. Long-term outcomes were also analyzed.

RESULTS

The calculated CUSUM learning curve comprised three phases: Phase I (the initial 15 cases), Phase II (the middle 15 cases), and Phase III (the final 20 cases). The resection speed was 5.7 ± 3.2 min/cm² in Phase I, 4.7 ± 2.7 min/cm² in Phase II, and 4.3 ± 2.2 min/cm² in Phase III. The resection speed was significantly faster in Phase II than in Phase I (p = 0.019). The rate of self-completion reached more than 95% in Phases II and III. The overall complete resection rate was 95%, showing no significant differences between the three phases. Local recurrence was diagnosed in none of the patients during a median follow-up of 38 months.

CONCLUSIONS

For the trainees, 30 cases were required to attain a higher technical level of competence in gastric ESD. After the learning curve phase, trainee operators could be expected to complete the procedure successfully with favorable long-term outcomes.

Histomorphologic features of early gastric carcinoma treated by endoscopic submucosal dissection: relation to efficiency of endoscopic resection

OBJECTIVE

Early gastric cancer (EGC) is defined as cancer invasion confined to the mucosa or submucosa, irrespective of lymph node metastasis. Recently endoscopic submucosal dissection (ESD) has been widely accepted for the treatment for dysplasia and EGC without lymph node metastases. While the method has been advanced in Far East countries, ESD is still being developed in Europe and has not gained enough popularity although it has been recommended as the treatment of choice for superficial gastric neoplastic lesions by European Society of Gastrointestinal Endoscopy (ESGE) in 2015.

METHODS

The aim of the study was to perform a retrospective analysis of clinical and histomorphologic features of 58 cases of EGCs removed by ESD in a university hospital in Western Pomerania in Poland and to evaluate factors related to the efficiency of ESD resection.

RESULTS

With univariate analysis, indications for ESD with the highest R0 rate were found in EGCs limited to mucosa (T1a, small mucosal, M), without muscularis mucosa invasion, localised in the middle/lower part of stomach and intestinal type in histological examination. The R0 complete resection rate was significantly (p < 0.0001) lower for T1b than that for T1a tumours (21.4% vs. 100%). Tumours with submucosal involvement were associated with lower efficiency of ESD procedure.

CONCLUSIONS

Our data showed that in EGCs with favourable histomorphologic characteristics, ESD seemed to be a totally efficient and safe method of treatment in a European small-volume centre. R0 resection rate reached 81.1% of cases and median time of the ESD procedure was 61.5 min.

Prevention of esophageal strictures after endoscopic submucosal dissection with the injection of botulinum toxin type A

BACKGROUND AND AIMS

The use of endoscopic submucosal dissection (ESD) for management of widespread superficial esophageal squamous carcinoma is closely associated with esophageal stenosis. We investigated the efficacy and feasibility of endoscopic injection of botulinum toxin type A (BTX-A) for preventing esophageal strictures after ESD for superficial esophageal squamous carcinoma.

METHODS

Sixty-seven patients with superficial esophageal squamous cell carcinomas with mucosal defects that exceeded one half of the circumference of the esophagus after ESD treatment were enrolled and randomly divided into 2 groups (group A, n = 33; group B, n = 34). Patients in group A (BTX-A group) were immediately injected with BTX-A after ESD, whereas patients in group B (control group) received ESD only. Endoscopy was performed when patients reported dysphagia symptoms and at 12 weeks post-ESD in patients without symptoms. Patients who experienced post-ESD esophageal strictures in both groups received bougie dilation.

RESULTS

The number of patients who experienced esophageal strictures in group A (per protocol analysis, 6.1%, 2/33; intention to treat analysis, 11.4%, 4/35) was significantly less than that seen in group B (per protocol analysis, 32.4%, 11/34; intention to treat analysis, 37.8%, 14/37) (P < .05). Moreover, the number of bougie dilation procedures was significantly lower in group A (mean, 1.5; range, 0-2) than in group B (mean, 2.8; range, 0-5) (P < .05).

CONCLUSIONS

Endoscopic injection of BTX-A was effective in preventing post-ESD esophageal strictures and decreasing the times of bougie dilation procedures. (

CLINICAL TRIAL REGISTRATION NUMBER

ChiCTR-TRC-12003188.).

The expansion of endoscopic submucosal dissection in France: A prospective nationwide survey

INTRODUCTION

Early reports of endoscopic submucosal dissection (ESD) in Europe suggested high complication rates and disappointing outcomes compared to publications from Japan. Since 2008, we have been conducting a nationwide survey to monitor the outcomes and complications of ESD over time.

MATERIAL AND METHODS

All consecutive ESD cases from 14 centers in France were prospectively included in the database. Demographic, procedural, outcome and follow-up data were recorded. The results obtained over three years were compared to previously published data covering the 2008-2010 period.

RESULTS

Between November 2010 and June 2013, 319 ESD cases performed in 314 patients (62% male, mean (±SD) age 65.4 ± 12) were analyzed and compared to 188 ESD cases in 188 patients (61% male, mean (±SD) age 64.6 ± 13) performed between January 2008 and October 2010. The mean (±SD) lesion size was 39 ± 12 mm in 2010-2013 vs 32.1 ± 21 for 2008-2010 (p = 0.004). En bloc resection improved from 77.1% to 91.7% (p < 0.0001) while R0 en bloc resection remained stable from 72.9% to 71.9% (p = 0.8) over time. Complication rate dropped from 29.2% between 2008 and 2010 to 14.1% between 2010 and 2013 (p < 0.0001), with bleeding decreasing from 11.2% to 4.7% (p = 0.01) and perforations from 18.1% to 8.1% (p = 0.002) over time. No procedure-related mortality was recorded.

CONCLUSIONS

In this multicenter study, ESD achieved high rates of en bloc resection with a significant trend toward better outcomes over time. Improvements in lesion delineation and characterization are still needed to increase R0 resection rates.

Comparison of O-Type HybridKnife to Conventional Knife in Endoscopic Submucosal Dissection for Gastric Mucosal Lesions

Endoscopic submucosal dissection (ESD) has been accepted as a minimal invasive alternative to surgery for localized superficial gastrointestinal neoplasms recently. However, the procedure remains to be technically challenging and time consuming. A new dissecting knife with partially insulated tip has been recently developed with built-in injection capability. The purpose of this study was to investigate whether the efficiency of ESD procedure could be improved with this new device. A total of 78 patients, who underwent ESD with gastric mucosal lesions including flat type polyps, adenoma or early gastric cancer, were randomly assigned to either ESD with O-type HybridKnife or conventional ESD knives without waterjet. Procedure time and related factors of ESD were analyzed. ESD procedure time was 43.0 (interquartile range, IQR 27.0-60.0) minutes in HybridKnife group compared to 60.5 (IQR 44.0-86.3) minutes in the control group (P = 0.001). There was no difference in the clinical outcome and the adverse event rate. The former demonstrated more favorable results in lesions ≤4 cm of specimen size (P ≤ 0.0001) and when located in the distal stomach (P = 0.001), also in lesions with fibrosis (P = 0.008). Multivariate regression analysis showed that O-type Knife (P ≤ 0.0001), specimen size (P ≤ 0.0001), and fibrosis (P ≤ 0.0001) were independent predictors of procedure time. The O-type HybridKnife yielded faster procedure time compared to the conventional knives in gastric ESD with a similar safety profile.

Endoscopic Resection Compared with Gastrectomy to Treat Early Gastric Cancer: A Systematic Review and Meta-Analysis

BACKGROUND

Endoscopic resection and gastrectomy are treatment modalities for early gastric cancer, but their relative benefits and risks are unclear. We conducted a systematic review and meta-analysis to compare endoscopic resection and gastrectomy for treating early gastric cancer.

METHODS

We searched PubMed, Embase, and the Cochrane Library until April 2015 for studies comparing endoscopic resection with gastrectomy for treatment of early gastric cancer. Outcome measures were five-year overall survival (OS), length of hospital stay and postoperative morbidity. We calculated pooled hazard ratio (HR), weighted mean difference (WMD) and odds ratio (OR) using random effects models.

RESULTS

Six studies comprising 1,466 patients (618 endoscopic resection and 848 gastrectomy) met inclusion criteria. Five-year OS was similar between endoscopic resection and gastrectomy (HR, 1.06; 95% CI: 0.61 to 1.83). Endoscopic resection was associated with shorter hospital stays (WMD, -6.94; 95% CI: -7.59 to -6.29) and reduced overall postoperative morbidity (OR, 0.36; 95% CI: 0.17 to 0.74).

CONCLUSIONS

While five-year OS is similar between endoscopic resection and gastrectomy, endoscopic resection offers a shorter hospital stay and fewer complications than gastrectomy for treating early gastric cancer. Endoscopic resection is a reasonable treatment for early gastric cancer with a negligible risk of lymph node metastasis.

Prevention of esophageal stricture after endoscopic submucosal dissection: a systematic review and meta-analysis

BACKGROUND

Endoscopic submucosal dissection (ESD) of extensive superficial cancers of the esophagus may progress with high rates of postoperative stenosis, resulting in significantly decreased quality of life. Several therapies are performed to prevent this, but have not yet been compared in a systematic review.

METHODS

A systematic review of the literature and meta-analysis were performed using the MEDLINE, Embase, Cochrane, LILACS, Scopus, and CINAHL databases. Clinical trials and observational studies were searched from March 2014 to February 2015. Search terms included: endoscopy, ESD, esophageal stenosis, and esophageal stricture. Three retrospective and four prospective (three randomized) cohort studies were selected and involved 249 patients with superficial esophageal neoplasia who underwent ESD, at least two-thirds of the circumference. We grouped trials comparing different techniques to prevent esophagus stenosis post-ESD.

RESULTS

We conducted different meta-analyses on randomized clinical trials (RCT), non-RCT, and global analysis. In RCT (three studies, n = 85), the preventive therapy decreased the risk of stenosis (risk difference = -0.36, 95 % CI -0.55 to -0.18, P = 0.0001). Two studies (one randomized and one non-randomized, n = 55) showed that preventative therapy lowered the average number of endoscopy dilatations (mean difference = -8.57, 95 % CI -13.88 to -3.25, P < 0.002). There were no significant differences in the three RCT studies (n = 85) in complication rates between patients with preventative therapy and those without (risk difference = 0.02, 95 % CI -0.09 to 0.14, P = 0.68).

CONCLUSIONS

The use of preventive therapy after extensive ESD of the esophagus reduces the risk of stenosis and the number of endoscopic dilatations for resolution of stenosis without increasing the number of complications.

Endoscopic Submucosal Dissection for Early Gastric Cancer using the Clutch Cutter: a large single-center experience

BACKGROUND AND STUDY AIMS

The Clutch Cutter (CC) was developed to reduce the risk of complications related to endoscopic submucosal dissection (ESD) using knives. The CC is able to grasp and coagulate and/or incise the targeted tissue using electrosurgical current, like a biopsy technique. The aim of this study was to evaluate the efficacy and safety of ESD using the CC (ESD-CC) for early gastric cancer (EGC).

PATIENTS AND METHODS

From June 2007 to March 2014, 325 consecutive patients with a diagnosis of EGC were enrolled in this prospective study. They had all satisfied the Japanese gastric cancer treatment guidelines for ESD indication, namely confirmation by preliminary endoscopy, endoscopic ultrasound, and endoscopic biopsies. The CC was used for all steps of ESD (marking, circumferential marginal incision, submucosal dissection, and hemostatic treatment). The therapeutic efficacy and safety were assessed.

RESULTS

The en-bloc resection rate was 99.7 % (324/325) and the R0 resection rate was 95.3 % (310/325). The mean operating time was 97.2 minutes. Perforation during ESD-CC occurred in one case (0.3 %), which was managed with conservative medical treatment after endoscopic closure of the perforation. Post-ESD-CC bleeding occurred in 11 cases (3.4 %), which were successfully treated by endoscopic hemostatic treatment. The R0 resection rate was significantly low in tumors > 20 mm (88.9 %), and in the exclusion indication group (73.7 %). Significant differences were seen in the mean operating time, depending upon tumor size, histologic type, location, and indication criteria.

CONCLUSIONS

ESD-CC is a technically efficient, safe, and easy method for resecting EGC.

Implementation of Endoscopic Submucosal Dissection for Gastric Lesions in Norway

BACKGROUND AND AIMS

Endoscopic submucosal dissection is a minimal invasive method for an en bloc resection of dysplasia or early cancer in the stomach. It was developed in Japan in the 1990s, but thus far has not been widely adopted in Western countries. The aim of this study is to report from the introductory phase of gastric endoscopic submucosal dissection in a small-volume Scandinavian center.

MATERIAL AND METHODS

The 15 first patients operated on with endoscopic submucosal dissection in the stomach at the University Hospital of North Norway were consecutively registered in a prospective database and evaluated as a quality assurance study. The indications for the procedures were diagnostic or therapeutic.

RESULTS

Three patients had benign lesions, three had low-grade dysplasia, five had high-grade dysplasia, two had neuroendocrine tumors, and two had early gastric cancers (T1b). The R0 resection rate was 83%. One neuroendocrine tumor was directed to surgery. No recurrences have been detected after the median of 6 months, and with the exception of one delayed bleeding being treated endoscopically, no serious complications occurred. Two perforations were perioperatively closed with clips.

CONCLUSION

This is the first report on gastric endoscopic submucosal dissection in Scandinavia. Preliminary results from an introductory phase indicate that endoscopic submucosal dissection for dysplasia or early gastric cancer may be conducted safely and with acceptable results even in a small-volume center, assuming that surgeons and gastroenterologists in a region direct cases to one individual who can learn this skill.

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.

Endoscopic Submucosal Dissection Using a Novel Versatile Knife: An Animal Feasibility Study (with Video)

Background/Aims

In order to reduce the procedure time and the number of accessory changes during endoscopic submucosal dissection (ESD), we developed a novel versatile knife, which has the combined advantages of several conventional knives. The aim of this study was to compare the efficacy, safety, and histological quality of ESD performed using this novel versatile knife and a combination of several conventional knives.

Methods

This was an in vivo animal study comparing two different modalities of ESD in mini-pigs. Completion time of each resection was documented, and the resected specimens were retrieved and evaluated for completeness. To assess the quality control of the procedures and adverse events, detailed histopathological examinations were performed.

Results

A total of 18 specimens were dissected by ESD safely and easily (nine specimens using the new versatile knife; nine specimens by mixing conventional knives). All resections were completed as en bloc resections. There was no significant difference in procedure time between the 2 modalities (456 seconds vs. 355 seconds, p=0.258) and cutting speed (1.983 mm²/sec vs. 1.57 mm²/sec, p=1.000). The rate of adverse events and histological quality did not statistically differ between the modalities.

Conclusions

ESD with a versatile knife appeared to be an easy, safe, and technically efficient method.

Prevention and treatment of esophageal stenosis after endoscopic submucosal dissection for early esophageal cancer

Endoscopic submucosal dissection (ESD) for the treatment of esophageal mucosal lesions is associated with a risk of esophageal stenosis, especially for near-circumferential or circumferential esophageal mucosal defects. Here, we review historic and modern studies on the prevention and treatment of esophageal stenosis after ESD. These methods include prevention via pharmacological treatment, endoscopic autologous cell transplantation, endoscopic esophageal dilatation, and stent placement. This short review will focus on direct prevention and treatment, which may help guide the way forward.

A double-blind, block-randomized, placebo-controlled trial to identify the chemical assistance effect of mesna submucosal injection for gastric endoscopic submucosal dissection

BACKGROUND

Previous animal studies and a pilot clinical trial demonstrated that submucosal injection of a thiol compound called mesna could chemically soften connective tissues and thus facilitate endoscopic submucosal dissection (ESD).

OBJECTIVE

To evaluate whether mesna injection could reduce procedural times for gastric ESD.

DESIGN

Double-blind, block-randomized, controlled trial.

SETTING

University hospital.

PATIENTS

A total of 101 patients with superficial gastric cancer indicated for ESD were enrolled and randomly assigned to either the mesna or control (saline solution) group.

INTERVENTION

Traditional ESD was performed with a single bolus injection of mesna or saline solution.

MAIN OUTCOME MEASUREMENTS

Time for submucosal dissection (TSD).

RESULTS

En bloc resection was achieved for all lesions in the mesna group (53/53) and 51 of 52 lesions (98.08%) in the control group. TSD was not statistically different between the groups (18.62 ± 13.9 [mean ± SD] minutes for the mesna group and 24.58 ± 24.55 [mean ± SD] minutes for the control group; P = .128), and there were fewer time-consuming cases (times over 30 minutes) in the mesna group compared with controls (7/53 vs 15/52; P = .049). Multivariate regression analysis demonstrated that use of mesna, specimen size, and the presence of fibrous scars were significantly correlated with TSD (P < .05).

LIMITATIONS

Single-center study.

CONCLUSION

TSD was not significantly different between the mesna and control injection groups, but multivariate analysis indicated that mesna injection reduced procedural challenges associated with the submucosal dissection. (

CLINICAL TRIAL REGISTRATION NUMBER

UMIN000003786.).

Preventing stricture formation by covered esophageal stent placement after endoscopic submucosal dissection for early esophageal cancer

OBJECTIVE

We aimed to evaluate the efficacy and safety of fully covered esophageal stent placement for preventing esophageal strictures after endoscopic submucosal dissection (ESD).

METHODS

Twenty-two patients with a mucosal defects that exceeded 75 % of the circumference of the esophagus after ESD treatment for superficial esophageal squamous cell carcinomas were grouped according to the type of mucosal defect and randomized to undergo fully covered esophageal stent placement post-ESD (group A, n = 11) or no stent placement (group B, n = 11). In group A, the esophageal stents were removed 8 weeks post-ESD. Endoscopy was performed when patients reported dysphagia symptoms and at 12 weeks post-ESD in patients without symptoms. Savary-Gilliard dilators were used for bougie dilation in patients experiencing esophageal stricture in both groups, and we compared the rates of post-ESD strictures and the need for bougie dilation procedures.

RESULTS

The proportion of patients who developed a stricture was significantly lower in group A (18.2 %, n = 2) than in group B (72.7 %, n = 8) (P < 0.05). Moreover, the number of bougie dilation procedures was significantly lower in group A (mean 0.45, range 0-3) than in group B (mean 3.9, range 0-17) (P < 0.05). The two patients in group A who experienced stricture also had stent displacement.

CONCLUSIONS

Esophageal stents are a safe and effective method of preventing esophageal strictures in cases where >75 % of the circumference of the esophagus has mucosal defects after ESD treatment for early esophageal cancer.

A pilot study using an infrared imaging system in prevention of post-endoscopic submucosal dissection ulcer bleeding

BACKGROUND

Endoscopic submucosal dissection (ESD) for superficial gastric neoplasm is a curative method. The aim of this study was to detect potential nonbleeding visible vessels (NBVVs) by using an infrared imaging (IRI) system.

METHODS

A total of 24 patients (25 lesions) were consecutively enrolled between March 2010 and December 2010. The day after ESD, endoscopist A (K.M.), who was blinded to the actual procedure of ESD, performed esophagogastroduodenoscopy (EGD) of the post-ESD ulcer base using the IRI system. Endoscopist A marked gray/blue points in the hard-copy images with the IRI system. After the first procedure, endoscopist B (Y.Y.), who was blinded to the results recorded by endoscopist A, performed a second EGD with white light endoscopy and administered water-jet pressure with the maximum level of an Olympus flushing pump onto the post-ESD ulcer base. This test can cause iatrogenic bleeding via application of pressure to NBVV in the post-ESD ulcer.

RESULTS

The IRI system detected 58 gray points and 71 blue points. The post-ESD ulcer was divided into the central area and the peripheral area. There were 14 gray points (24 %) in the central area and 44 gray points (76 %) in the peripheral area. There were 19 blue points (27 %) in the central area and 52 blue points (73 %) in the peripheral area. There was no significant difference when comparing the distribution of gray points and blue points. Bleeding occurred with a water-jet pressure in 11 of 58 gray points and in none of the blue points (P = 0.000478). Among the gray points, bleeding in response to a water-jet pressure occurred in 2 points in the central area and in 9 points in the peripheral area.

CONCLUSION

The IRI system detects visible vessels (VVs) that are in no need of coagulation as blue points, and VVs have a potential risk of bleeding as gray points.

Relevant risk factors and prognostic impact of positive resection margins after endoscopic submucosal dissection of superficial esophageal squamous cell neoplasia

BACKGROUND

Endoscopic submucosal dissection (ESD) for the treatment of esophageal mucosal lesions has a risk of resection margin residues. The related risk factors and prognosis of post-ESD resection margin residues have not been fully evaluated. The aim of this study was to investigate the associated risk factors and the prognostic impact of resection margin residues after ESD of superficial esophageal squamous cell neoplasia.

METHODS

We conducted a retrospective analysis of medical records at our hospital, including the clinical, endoscopic, and pathological data from patients who underwent ESD for the treatment of superficial esophageal squamous cell neoplasia from January 2008 to December 2012. In addition, we conducted a statistical analysis of the following factors: sex, age, location, the proportion of circumferential extension, the maximum diameter of the resected specimen, macroscopic type, the depth of invasion, and the endoscopists.

RESULTS

A total of 145 patients were included in the study. Overall, 148 lesions were completely resected. There were 17 patients (17 lesions) presenting with positive resection margin after ESD and the positive rate was 11.5 %. A total of 16 patients were followed-up. Among the patients who had resection margin residues, three underwent surgical esophageal resection, one underwent radiotherapy, two received ESD, and one received endoscopic mucosal resection. The remaining nine patients were periodically followed-up, and no recurrences were found. The results of a one-dimensional analysis suggested that there were significant differences in the maximum diameters of the resected specimens, macroscopic type, and the depth of invasion between the positive resection margin group and the negative resection margin group. The results of a multivariate regression analysis suggested that the maximum diameter of the resected specimens and the depth of invasion were risk factors for resection margin residues.

CONCLUSIONS

The maximum diameter of the resected specimens and the depth of tumor invasion are risk factors for post-ESD positive resection margins, which suggests that larger lesions and a greater depth of invasion increases the chance of residual tumor after ESD.

Colorectal endoscopic submucosal dissection: is it suitable in western countries?

Endoscopic submucosal dissection (ESD) represents a significant advance in therapeutic endoscopy with the major advantage being the ability to achieve a higher en bloc resection rate for early stage lesions. Western endoscopists infrequently perform colorectal ESD (CR-ESD) because of the greater technical difficulty involved, longer procedure times, and increased risk of perforation. Specialized training and sufficient clinical experience are necessary to successfully perform ESDs, but a systematic education and training program has still not been established in Japan or elsewhere in the world. Experts generally acknowledge that the stomach is the first organ in which endoscopists should begin performing ESDs. The incidence and detection rates for early stage gastric cancer are significantly higher in Japan than in western countries, so Japanese endoscopists have a greater opportunity to perform gastric ESDs than their western counterparts. It is logical to ask, therefore, whether CR-ESD can be effectively applied in western countries. Based on a review of the relevant literature and our practical perspective, we have focused on the progress made in performing CR-ESD, its indications, training methods, and learning curve. Use of animal gastric and colon models is strongly recommended along with accumulating the necessary experience from the rectum to the colon on a step-by-step basis. It is reasonable to assume that an increasing number of CR-ESDs will be performed by western endoscopists in the foreseeable future given the continuing development of new techniques, and the refinement of instruments and other technologically advanced devices together with the creation of even more effective submucosal injection agents.

Submucosal endoscopy with mucosal resection: a hybrid endoscopic submucosal dissection in the porcine rectum and distal colon

BACKGROUND

Endoscopic submucosal dissection (ESD) has appeal for en bloc resection of large flat colorectal polyps but carries appreciable risk and demands a high level of expertise and training. Undermining flat and laterally spreading colorectal polyps by using submucosal endoscopy with the mucosal safety valve flap (SEMF) may be combined with ESD to offer a hybrid technique that is easier and safer.

OBJECTIVE

To determine the feasibility of combining SEMF and ESD for the removal of progressively larger areas of the mucosa in the porcine rectum and colon.

DESIGN

Two-phase ex vivo and in vivo study using domestic pig rectum and distal colon.

SETTING

Developmental endoscopy unit/animal research unit.

INTERVENTIONS

Progressively larger targeted mucosal dissections were performed by using the basic principles of ESD, which included margination of the targeted area of mucosa, submucosal fluid cushion, and needle-knife dissection. These were combined with the SEMF method of predissection with carbon dioxide (CO(2)) gas and balloon-based blunt dissection of the submucosa undermining the targeted and isolated mucosa. The hybrid technique was first applied to ex vivo porcine rectums and distal colons, then in vivo in an acute animal study. Progressively larger staged dissections were performed with 2-, 4-, and 6-cm diameter targeted mucosal sites.

MAIN OUTCOME MEASUREMENTS

Success with associated difficulty or failure of the hybrid method in the rectum and distal colon to achieve complete resection of a progressively larger targeted area of mucosa.

RESULTS

The ex vivo phase of the experiment demonstrated the ability to use the blunt balloon dissection of the SEMF procedure to remove 2-, 4-, and 6-cm areas of rectum and distal colon with a rapid progression to the largest size resection. The colon proximal to 20 cm above the anus was unable to hold a submucosal fluid cushion and allow submucosal dissection. Successful hybrid ESD was performed in vivo with staged progression through to the largest mucosal area (6 cm) within 20 cm of the anus. Dissections became progressively easier and faster to perform and dependent on the following steps: a traditional circumferential mucosal incision into the deep submucosa, an initial needle-knife submucosal "tunnel" dissection above the muscularis propria (MP), balloon dissection, and needle-knife release of persistent tethering strands of submucosa with and without vessels. Of 16 hybrid resections, 3 failures and 2 very difficult resections were attributed to attempts at resection too proximal in the colon, excessive flexibility of the balloon catheter, and electrosurgical device subperformance. There were no mucosal perforations or coagulation injuries to the MP. A single uninflated balloon catheter perforation of the MP occurred in a dissection site just above 20 cm from the anus with a suboptimal fluid cushion.

LIMITATIONS

Animal study. Procedures performed by a single endoscopist with long-standing familiarity with the SEMF method.

CONCLUSIONS

Large mucosal target sites in the rectum and distal colon of the pig can be safely removed en bloc by means of a hybrid technique, ie, submucosal endoscopy with mucosal resection, combining elements of ESD with our SEMF method.

Endoscopic submucosal dissection--current success and future directions

More than 10 years have passed since endoscopic submucosal dissection (ESD) was first developed in Japan. ESD enables en bloc complete resection of superficial gastrointestinal neoplasms regardless of the size and location of the lesions. With improvements in techniques and devices, excellent therapeutic results have been achieved despite the inherent technical difficulties of this procedure. ESD aiming for curative treatment can be performed for gastrointestinal neoplasms without risk of lymph node metastasis. Accurate histopathologic examination of the resected specimen is required to determine the risk of lymph node metastasis, for which en bloc resection is beneficial. Owing to the high success rate of en bloc complete resection and accurate histopathologic examination, tumour recurrence rates after ESD are reported to be very low in Japan. Excellent results of ESD in a large number of cases have also been reported from other Asian countries such as South Korea, Taiwan and China. Although scepticism exists among Western clinicians regarding the application of ESD, it is developing slowly and reports indicate promising results in some European countries. With further development of technologies, such as endoscopic robotics, ESD could become the worldwide treatment of choice for early gastrointestinal neoplasms.

Colorectal endoscopic submucosal dissection in Japan and Western countries

Various studies by Japanese endoscopists have demonstrated that colorectal endoscopic submucosal dissection (ESD) can overcome technical limitations of the endoscopic mucosal resection (EMR) technique such as piecemeal resection for flat lesions larger than 20 mm, resection of lesions involving the dentate line or the ileocecal valve and lesions with the non-lifting sign, and achieve higher en bloc resection rate. However, it is infrequently performed in Western countries in comparison with Japan, despite the advantages explained above. There are some differences between Japan and Western countries in environments and clinical settings for performing ESD in the colorectum. Endoscopists who perform colorectal ESD around the world are considering that refinements in ESD techniques, devices and training will be necessary to further reduce a higher risk of complications and longer procedure times before adoption of ESD can be recommended on a widespread international scale.

Current status of training for endoscopic submucosal dissection for gastric epithelial neoplasm at Cancer Institute Hospital, Japanese Foundation for Cancer Research, a famous Japanese hospital

AIM

Endoscopic submucosal dissection (ESD) is relatively difficult compared with endoscopic mucosal resection (EMR), thus, proper training is essential for the safe performance of the procedure. The aim of this study is to clarify the current status of training for ESD for gastric epithelial neoplasm by following the performance of 13 preceptees.

METHODS

We performed ESD for 1520 lesions between March 2005 and April 2011 and conducted ESD training of 13 preceptees who were supervised by experts. We classified the samples into four groups according to the number of ESD performed by the preceptees to chart their progress by comparing the procedural outcomes. Group A included cases 1-40 performed by all 13 preceptees, group B consisted of cases 41-80 performed by 10 of the preceptees and group C included cases 81 onwards executed by five of the preceptees. Group D comprised the cases that were performed by experts during the same period as group C.

RESULTS

The procedural outcomes of group A were similar to those of group B with regard to operation time, complete en bloc resection and complications. However, the results of group B included significantly more lesions of the middle or upper third of the stomach, resected specimen and lesions were larger in diameter, lesions with positive ulcer finding were more frequent and a higher frequency of lesions were of expanded, non-indication type. Group B outcomes were similar to those of group C but differed in location of lesions and specimen size. Group C outcomes were similar to group D's in all parameters.

CONCLUSION

Preceptees were able to safely perform ESD for gastric epithelium neoplasms under appropriate supervision by expert endoscopists. The number of cases in which preceptees successfully extracted guideline-indication lesions and expanded-indication lesions by ESD were approximately 40 and 80 cases, respectively. The procedural outcomes of ESD performed by preceptees who had experience in over 80 cases were similar to those by expert endoscopists. Thus, these findings show that the minimal amount of training for achieving preceptorship of ESD is performance of at least 80 of the procedures.

Current situation of endoscopic submucosal dissection for superficial neoplasms in the upper digestive tract in East Asian countries: a questionnaire survey

AIM

This study was carried out to understand the current practice and learning of endoscopic submucosal dissection (ESD) for superficial esophageal and gastric cancers in East Asian countries.

METHODS

A questionnaire survey was used to investigate differences in upper gastrointestinal (GI) ESD among East Asian countries.

RESULTS

ESD is used by many endoscopists in not only tertiary centers but also secondary care hospitals in China, Korea and Japan. By contrast, it is less used by doctors in tertiary centers in Hong Kong and Taiwan. However, the general trend appears to be the same; ESD, which is a highly advanced endoscopic technique, is being transmitted from preceptors to preceptees in tertiary centers, then from doctors in tertiary centers to experienced doctors in secondary hospitals. The speed of learning and uptake in the practice of this procedure will depend on the volume of cases. Upper GI ESD can be expected to spread at a similar rate across different districts or hospitals in East Asia because of similarities in disease prevalence. Also, endoscopists in this region can easily learn from each other by attending international conferences or visiting endoscopy units to learn the procedure.

CONCLUSION

Efforts to establish a standardized protocol for ESD practice and training are important, and may help endoscopists around the world develop this technique further.

Gastric endoscopic submucosal dissection assisted by a new traction method: the clip-band technique. A feasibility study in a porcine model (with video)

BACKGROUND

Endoscopic submucosal dissection (ESD) is the standard of care for treating gastric intramucosal neoplasias in Japan. However, it is seldom performed in Western countries, mainly because it is technically very challenging. Several traction methods have been proposed to facilitate submucosal dissection, but they are usually not widely available or are difficult to apply.

OBJECTIVE

Our main aim was to evaluate the feasibility of a new method, the clip-band technique, for improving the visualization of the submucosal layer during ESD.

DESIGN

Observational, experimental, feasibility study conducted in a porcine model.

SETTING

University Hospital of the Canary Islands, Research Animal Laboratory.

PATIENTS

Animal study.

INTERVENTIONS

After completion of the circumferential cutting, a clip-band traction system was applied.

MAIN OUTCOME MEASUREMENTS

Efficacy and safety of the clip-band technique.

RESULTS

Eighteen ESDs performed in live domestic pigs were completed without any serious complications. The mean specimen size was 35.38 ± 12.17 mm, the mean cutting time was 13.06 ± 10.52 minutes, and the mean dissection time was 16.67 ± 9.01 minutes.

LIMITATIONS

The clip-band technique was not compared with the standard ESD technique.

CONCLUSIONS

This initial study shows that the clip-band traction technique is feasible and that it permits safe, effective, and relatively inexpensive gastric ESD.

Learning curve in a Western training center of the circumferential en bloc esophageal endoscopic submucosal dissection in an in vivo animal model

Aim. Evaluate the feasibility to overcome the learning curve in a western training center of the en bloc circumferential esophageal (ECE-) ESD in an in vivo animal model. Methods. ECE-ESD was performed on ten canine models under general anesthesia on artificial lesions at the esophagus marked with coagulation points. After the ESD each canine model was euthanized and surgical resection of the esophagus and stomach was carried out according to "the Principles of Humane Experimental Technique, Russel and Burch." The specimen was fixed with needles on cork submerged in formalin with the esophagus and stomach then delivered to the pathology department to be analyzed. Results. ECE-ESD was completed without complications in the last 3/10 animal models. Mean duration for the procedures was 192 ± 35 minutes (range 140-235 minutes). All the procedures were done at the animal lab surgery room with cardio pulmonary monitoring and artificial ventilation by staff surgery members and a staff member of the Gastroenterology department trained during 1999-2001 at the Fujigaoka hospital of the Showa U. in Yokohama, Japan, length (range 15-18 mm) and 51 ± 6.99 width (range 40-60 mm). Conclusion. ECE-ESD training is feasible in canine models for postgraduate endoscopy fellows.

Experimental endoscopic submucosal dissection training in a porcine model: learning experience of skilled Western endoscopists

BACKGROUND

Endoscopic submucosal dissection (ESD) demands a new level of endoscopic skill in Europe. A 2-day workshop was set up for trainees to carry out five ESD each in order to obtain the skill level required to perform ESD in the stomach or rectum. This study describes: (i) the workshop setup; (ii) the participant's performance; and (iii) the training effect on post-workshop clinical ESD performance.

METHODS

Eighteen very experienced European endoscopists participated in four half-day (4.5 h) training sessions, with everybody rotating daily through six separate training stations (two each with dual, hook, or hybrid knives) with expert tutors. One anesthetized piglet was used per station and session. After 1 year, the clinical ESD performance was surveyed to estimate the training effect of the workshop.

RESULTS

Overall, 74 ESD were performed, that is, 4.1 ESD per participant. On average ESD lasted 57 min for 6 cm(2) specimens. We detected a 22% rate of perforation (16 of 74 ESD with perforations), mostly attributable to participants with less experience in ESD. Those who started clinical ESD within 1 year after the workshop performed 144 clinical ESD (median 8 [0-20] per trainee) mostly in the stomach (40%) and large bowel (46%) with an acceptable rate of perforation (9.7%) and surgical repair (3.5%) without mortality or persistent morbidity.

CONCLUSION

Intense skill training for ESD is needed to reduce the risk of perforation, as demonstrated by the results of this workshop. We show that experimental ESD training, however, enables skilled European endoscopists to perform ESD in standard locations with moderate risk of perforation during the clinical learning curve.

Feasibility study of corticosteroid treatment for esophageal ulcer after EMR in a canine model

BACKGROUND

Intralesional or systemic steroid administration is a promising strategy for the prevention of esophageal stricture after endoscopic therapy. The aim of this study was to evaluate the influence of steroid therapy on the process of healing of defects in the esophageal mucosa after endoscopic mucosal resection (EMR).

METHODS

Nine beagle dogs were divided into three equal groups: group A, intralesional injection (n = 3), group B, peroral administration (n = 3), and group C, untreated control (n = 3). In group A, triamcinolone acetonide 1 ml (10 mg) was injected directly into the exposed submucosal layer immediately after EMR, and again on postoperative day (POD) 7. In group B, dogs were administered prednisolone 0.5 mg/kg/day orally for 14 days after EMR. In group C, 1 ml normal saline was injected by the same method as that used for group A. On POD 28, histological examination was performed to evaluate epithelialization, inflammation, angiogenesis, and atrophy of the muscularis propria.

RESULTS

In groups A, B, and C, the mean ulcer area was 50.1, 22.7, and 7.4 mm(2), respectively. The difference between groups A and C was significant (p < 0.01). Inflammatory cells were significantly more evident in the lesions of group A than in those of group C (p < 0.05). In all groups, atrophy of the muscularis propria was evident. However, transmural destruction and fibrosis were observed only in group A.

CONCLUSION

It was speculated that the esophageal ulcer causes the fibrosis of the submucosa and atrophy of the muscularis propria during process of healing. Intralesional steroid injection deepened the esophageal ulcers and delayed epithelialization, whereas systemic administration did not clearly improve the lesion healing process.

Chicken soup for teaching and learning ESD

Endoscopic submucosal dissection (ESD) is becoming a popular procedure for the diagnosis and treatment of superficial mucosal lesions, and has the advantage of en bloc resection which yields a higher complete resection and remission rate compared to endoscopic mucosal resection (EMR). However, the learning process of this advanced endoscopic procedure requires a lengthy training period and considerable experience to be proficient. A well framed training protocol which is safe, effective, easily reproducible and cost-effective is desirable to teach ESD. In addition, the training course may need to be tailored around settings such as ethnicity, culture, workload, and disease incidence. In Asian countries with a large volume of early gastric lesions which need endoscopic treatment, endoscopists would be able to learn ESD expanding their skills from EMR to ESD under the supervision of experts. Whereas, in Western countries due to the low incidence of superficial gastric tumors, trials have utilized simulator models to improve learning. In Korea, the Korean Society of Gastrointestinal Endoscopy (KSGE) is playing an important role in training many gastroenterologists who have shown an interest in performing ESD by providing an annual live demonstration and a nationwide tutoring program. The purpose of this article is to introduce our ESD tutoring experience, review the published papers related to this topic, and propose several suggestions for future directions in teaching and learning ESD.

Worldwide experiences of endoscopic submucosal dissection: Not just Eastern acrobatics

The high incidence of gastric cancer has led to the initiation of cancer screening programs. As a result, the number of early gastric cancer cases has increased and consequentially, the cancer mortality rate has decreased. Moreover, the development of minimally invasive endoscopic treatment has been introduced for these early lesions. Endoscopic submucosal dissection (ESD) is now recognized as one of the preferred treatment modalities for premalignant gastrointestinal epithelial lesions and early gastric cancer without lymph node metastasis. We review the results of ESD including experiences in Japan and Korea, as well as western countries.

Prospective, randomized study of conventional versus HybridKnife endoscopic submucosal dissection methods for the esophagus: an animal study

BACKGROUND

Endoscopic submucosal dissection (ESD) increases en bloc and histologically complete resection rate of neoplastic mucosal tumors but is technically more demanding than EMR. Limited data are available comparing the efficacy and safety of a new ESD designed to overcome these limitations and conventional ESD (C-ESD) techniques.

OBJECTIVE

To compare the safety, efficacy, and operation time of the new HybridKnife ESD (HK-ESD) with C-ESD in the esophagus.

DESIGN

Prospective, randomized, controlled study.

SETTING

Animal research laboratory.

SUBJECTS

Seventeen anesthetized Yorkshire pigs.

INTERVENTIONS

Removal of a 4-cm length of half-circumference esophageal mucosa by C-ESD with Hook knife or Flexknife versus HK-ESD.

MAIN OUTCOME MEASUREMENTS

Procedure time, en bloc and complete resection rate, and complications (bleeding and perforation).

RESULTS

All resections were completed en bloc. Procedure time was shorter in C-ESD. However, it was similar after 12 procedures. Significantly more bleeding occurred during C-ESD (28 vs 12, P = .0007). Histological muscularis propria injuries occurred with equal frequency (16 vs 17) and were mostly seen during the first 11 procedures. There were 3 perforations (2 endoscopic, 1 histological), all with C-ESD.

LIMITATIONS

Nonsurvival study, use of 2 conventional knives, no training period for a new procedure.

CONCLUSIONS

The HK-ESD technique was equally effective as the C-ESD technique for successful en bloc resection and was safer with less bleeding and perforation. Although procedure time was longer in HK-ESD, the difference became nonsignificant after 12 procedures.

Clinical outcomes of ESD for early gastric neoplasms in elderly patients

BACKGROUND

Endoscopic submucosal dissection (ESD) is a standard treatment in Japan for early gastric neoplasms. With an increase in elderly population, the number of elderly patients in whom ESD performed has also steadily increased.

AIMS AND METHODS

 The aim of study was to evaluate the effectiveness of and problems associated with ESD for early gastric neoplasms in elderly patients. Subjects were 514 patients (586 lesions) with early gastric neoplasms performed ESD at two institutions. The patients were classified into an elderly group (age ≥ 75 years) and a nonelderly group (age < 75 years). We compared the characteristics of patients and lesions, treatment results, ESD-related complications and prognosis between the two groups.

RESULTS

The elderly group included 200 patients (229 lesions), and the nonelderly group included 314 patients (357 lesions). The incidences of underlying disease, such as hypertension and heart disease, and the rate of antiplatelet agents use were significantly higher in the elderly group. En bloc and curative resection rates were high in both groups. The bleeding rate was significantly higher in the elderly group. Residual disease or recurrence rates were very low in both groups. The death rate due to other diseases was significantly higher in the elderly group.

CONCLUSIONS

This study demonstrates the efficacy of ESD in both elderly and nonelderly patients. However, we must be attentive to ESD-related bleeding, death caused by other diseases, and underlying diseases when we perform ESD in elderly patients.

Three-dimensional MDCT for preoperative local staging of gastric cancer using gas and water distention methods: a retrospective cohort study

OBJECTIVE

The purpose of this article is to compare the T-staging accuracy and lesion detectability of MDCT with gas distention versus water distention according to the surgical and histopathologic findings, for the preoperative evaluation of gastric cancer.

MATERIALS AND METHODS

For a 3-month period, 113 consecutive patients (72 men and 41 women; age range, 23-85 years; mean age, 58 years) with 116 surgically confirmed gastric cancers from a single institution were included in our study. All patients had undergone preoperative MDCT with either effervescent granules taken orally (n = 55) or after having drunk 1,000 mL of tap water (n = 58) to create gastric distention. In addition to transverse images, multiplanar reformation images and 3D surface shaded display images were also obtained with gas distention CT, and multiplanar reformation images were obtained with water distention CT. The CT images were retrospectively reviewed by two abdominal radiologists separately with regard to T staging and lesion detectability. The accuracy values were compared between the two methods using Fisher's exact test.

RESULTS

The T-staging accuracy for gastric cancer did not differ significantly between gas distention and water distention CT scans, according to both radiologists (p > 0.05). Furthermore, the staging accuracy values for T1a cancers on gas distention CT scans for radiologists 1 and 2 were also comparable with those of water distention CT scans (91.1% vs 85% for radiologist 1 and 89.3% vs 85% for radiologist 2; p > 0.05). However, the tumor detection rate was significantly higher on gas distention CT scans using 2D and surface shaded display images for both radiologists (94.6% for radiologist 1 and 91.1% for radiologist 2), compared with the rates for water distention CT scans (78.3% and 73.3%) or gas distention CT scans using only 2D images (75.0% and 67.9%) (p < 0.05).

CONCLUSION

MDCT using the gas distention technique showed performance comparable to that of the water distention technique for the T staging of preoperative gastric cancer with better lesion detectability.

Endoscopic submucosal dissection using a grasping-type scissors forceps for early gastric cancers and adenomas

AIM

To reduce the risk of complications related to endoscopic submucosal dissection (ESD) using knives, we developed a new grasping-type scissors forceps (GSF) that can grasp and incise the target tissue using electrosurgical current. The aim of the present study was to evaluate the efficacy and safety of ESD using GSF for the removal of early gastric cancers and adenomas.

METHODS

ESD using GSF was carried out on 35 consecutive patients with early gastric cancers or adenomas who had preoperative EUS diagnoses of mucosal tumor without lymph node involvement. Therapeutic efficacy and safety were assessed.

RESULTS

All lesions were treated easily and safely without unexpected incision. The mean size of epithelial tumors and resected specimens was 15.6mm and 32.7mm, respectively. Curative en-bloc resection rates according to tumor size and location were 96% (26/27) in tumors ≤20mm, 100% (8/8) in tumors >20mm, 100% (18/18) of tumors in the lower portion, 100% (8/8) of tumors in the middle portion, 89% (8/9) of tumors in the upper portion, and 97% (34/35) overall. The mean operating time according to tumor size and location was 93.4min in tumors ≤20mm, 140min in tumors >20mm, 77.6min for tumors in the lower portion, 113.4min for tumors in the middle portion, 148.6min for tumors in the upper portion, and 104.1min overall. No intraoperative complication occurred, and postoperative bleeding was seen in 3% (1/35).

CONCLUSIONS

ESD using GSF allows simple and safe en-bloc resection of early gastric cancer or adenoma irrespective of tumor size and location.

Endoscopic submucosal dissection with electrosurgical knives in a patient on aspirin therapy (with video)

BACKGROUND

The electrosurgical knives required to perform endoscopic submucosal dissection (ESD) have recently passed the 510(k) premarketing evaluation by the U.S. Food and Drug Administration and are now available for purchase in the United States. Challenges to ESD being more widely performed in the United States include the lack of intensive hands-on training programs and a low incidence of appropriate, highly dysplastic gastric lesions on which an ESD-trained endoscopist can begin performing this procedure in patients. Furthermore, there are no guidelines regarding the safety of continuing antiplatelet therapy in patients undergoing ESD.

OBJECTIVE

To report on the first gastric ESD performed in the United States by using recently approved electrosurgical knives on a patient who was maintained on aspirin therapy.

DESIGN

Case report.

SETTING

Large academic medical center.

PATIENT

One patient with a 2-cm high-grade dysplasia (HGD) lesion in the posterior antrum who had indwelling coronary stents and was maintained on aspirin therapy throughout the periprocedural period.

INTERVENTIONS

High-definition white-light and narrow-band imaging endoscopy, endosonography, and ESD by using recently approved electrosurgical knives.

MAIN OUTCOME MEASUREMENTS

Complete resection of the HGD gastric lesion.

RESULTS

En bloc complete resection of the HGD gastric lesion was achieved without any immediate or delayed bleeding or perforation. No residual or recurrent dysplasia was found on 1- or 3-month follow-up endoscopies.

LIMITATIONS

Generalizations cannot be made from this single case.

CONCLUSIONS

After receiving intensive hands-on training in both ex vivo and in vivo animal models, gastric ESD was successfully performed by 2 U.S. endoscopists by using recently approved electrosurgical knives in a patient maintained on aspirin therapy without any complications.

Endoscopic submucosal dissection in dogs in a World Gastroenterology Organisation training center

AIM: To evaluate if canine models are appropriate for teaching endoscopy fellows the techniques of endoscopic submucosal dissection (ESD).

METHODS: ESD was performed in 10 canine models under general anesthesia, on artificial lesions of the esophagus or stomach marked with coagulation points. After ESD, each canine model was euthanized and surgical resection of the esophagus or stomach was carried out according to “The Principles of Humane Experimental Technique, Russel and Burch”. The ESD specimens were fixed with needles on cork submerged in a formol solution with the esophagus or stomach, and delivered to the pathology department to be analyzed.

RESULTS: ESD was completed without complications using the Hook-knife in five esophageal areas, with a procedural duration of 124 ± 19 min, a length of 27.4 ± 2.6 mm and a width of 21 ± 2.4 mm. ESD was also completed without complications using the IT-knife2 in five gastric areas, with a procedural duration of 92.6 ± 19 min, a length of 32 ± 2.5 mm and a width of 18 ± 3.7 mm.

CONCLUSION: ESD is feasible in the normal esophagus and stomach of canine models, which are appropriate for teaching this technique.

A new breakthrough: ESD using a newly developed grasping type scissor forceps for early gastrointestinal tract neoplasms

Endoscopic submucosal dissection (ESD) has allowed the achievement of histologically curative en bloc resection of gastrointestinal neoplasms regardless of size, permitting the resection of previously non-resectable tumors. The ESD technique for treatment of early gastric cancer has spread rapidly in Japan and a few other Asian countries due to its excellent eradication rate compared to endoscopic mucosal resection. Although numerous electrosurgical knives have been developed for ESD, technical difficulties and high complication rates (bleeding and perforation) have limited their use worldwide. We developed the grasping type scissor forceps (GSF) to resolve such ESD-related problems. Our animal and preliminary clinical studies showed that ESD using GSF is a safe (no intraoperative complication) and technically efficient (curative en bloc resection rate 92%) method for dissection of early gastrointestinal tumors. The use of GSF is a promising option for performing ESD on early stage GI tract tumors both safely and effectively.