The Efficacy of an Endoscopic Grasp-and-Traction Device for Gastric Endoscopic Submucosal Dissection: An Ex Vivo Comparative Study (with Video)

Endoscopic mucosal resection and endoscopic submucosal dissection with an external additional working channel (EMR+ and ESD+) are equivalent to using a double-channel endoscope: a systematic evaluation in a porcine ex vivo model

BACKGROUND AND AIMS

With an external additional working channel (AWC) endoscopic mucosal resection (EMR) as well as endoscopic submucosal dissection (ESD) can be extended to techniques termed "EMR+" and "ESD+." These novel techniques are systematically compared to EMR and ESD under the use of a double-channel endoscope (DC).

METHODS

Our trial was conducted prospectively in a pre-clinical porcine animal model (EASIE-R simulator) with standardized gastric lesions measuring 3 or 4 cm.

RESULTS

EMR+ and EMR DC showed both good results for 3 cm lesions with no adverse events and an en bloc resection rate of 73.33% (EMR+) and 60.00% (EMR DC, p = 0.70). They came to their limits in 4 cm lesions with muscularis damages of 20.00% (EMR+), 13.33% (EMR DC, p ≥ 0.99) and decreasing en bloc resection rates of 60.00% (EMR+) and 46.67% (EMR DC, p = 0.72). ESD+ and ESD DC were both reliable concerning en bloc resection rates (100% in all groups) and adverse events (0.00% in 3 cm lesions, 12.50% muscularis damages in both ESD+ and ESD DC in 4 cm lesions). Resection time was slightly shorter in all groups with the AWC compared to DC although only reaching significance in 3 cm ESD lesions (p < 0.05*).

CONCLUSIONS

With the AWC, a standard endoscope can easily be transformed to double-channel functionality. We could show that EMR+ and ESD+ are non-inferior to EMR and ESD under the use of a double-channel endoscope. Consequently, the AWC presents an affordable alternative to a double-channel endoscope for both EMR and ESD.

Endoscopic Submucosal Dissection Facilitating Techniques Among Non-experts: A Systematic Literature Review

BACKGROUND AND AIMS

The dissemination of endoscopic submucosal dissection (ESD) has been limited by its technical complexity and safety profile, particularly among non-experts. Various techniques and devices have facilitated the performance of ESD, but their yield and role in the path to learning ESD remain unclear.

METHODS

We performed a systematic review by querying MEDLINE, EMBASE, Web of Science, and Japan Medical Abstracts Society specifically for comparative studies investigating the impact of assigned ESD techniques vs. conventional techniques among non-experts in ESD (< 50 ESD procedures). Procedural outcomes of efficacy, efficiency, and safety were assessed.

RESULTS

We identified 46 studies evaluating 54 cohorts in which a total 237 non-experts performed 2461 ESDs conventionally, and 1953 ESDs using an assigned ESD technique (knives, countertraction, miscellaneous techniques). The majority of studies were from East Asia (67%), single-center (96%), observational in design (61%), in an animal model (57%), and gastric location (63%). The most studied techniques were countertraction techniques (48% cohorts) and scissor knives (15% cohorts), both of which commonly enhanced efficiency of ESD, and less so efficacy or safety. Techniques found to be beneficial in experts were more likely to be beneficial in non-experts (70% concordance) than vice versa (47% concordance).

CONCLUSION

Based on the currently available literature, countertraction techniques and scissor knives should be considered for early incorporation into ESD training by non-experts. Several aspects of ESD training remain understudied, including techniques in Western non-experts, educational resources, and several commonly cited techniques. These areas should guide future investigation to enhance the pathway to learning ESD.

Endoscopic diagnosis and treatment of gastric dysplasia and early cancer: Current evidence and what the future may hold

Gastric cancer accounts for a significant proportion of worldwide cancer-related morbidity and mortality. The well documented precancerous cascade provides an opportunity for clinicians to detect and treat gastric cancers at an endoscopically curable stage. In high prevalence regions such as Japan and Korea, this has led to the implementation of population screening programs. However, guidelines remain ambiguous in lower prevalence regions. In recent years, there have been many advances in the endoscopic diagnosis and treatment of early gastric cancer and precancerous lesions. More advanced endoscopic imaging has led to improved detection and characterization of gastric lesions as well as superior accuracy for delineation of margins prior to resection. In addition, promising early data on artificial intelligence in gastroscopy suggests a future role for this technology in maximizing the yield of advanced endoscopic imaging. Data on endoscopic resection (ER) are particularly robust in Japan and Korea, with high rates of curative ER and markedly reduced procedural morbidity. However, there is a shortage of data in other regions to support the applicability of protocols from these high prevalence countries. Future advances in endoscopic therapeutics will likely lead to further expansion of the current indications for ER, as both technology and proceduralist expertise continue to grow.

Endoscopic submucosal dissection with an additional working channel (ESD+): a novel technique to improve procedure time and safety of ESD

Background and aims

A new external additional working channel (AWC) was recently introduced by which endoscopic submucosal dissection (ESD) can be converted to a technique termed “ESD+ ”. We aim to systematically evaluate this novel technique in flat gastric lesions and compare it to classical ESD.

Methods

The study was prospectively conducted in a pre-clinical ex vivo animal model (EASIE-R simulator) with porcine stomachs. Prior to intervention, we set standardized lesions measuring 3 cm or 4 cm in antegrade as well as in retrograde positions.

Results

Overall, 64 procedures were performed by an experienced endoscopist. Both techniques were reliable and showed en bloc resection rates of 100%. Overall, ESD+ reduced time of procedure compared to ESD (24.5 vs. 32.5 min, p = 0.025*). Particularly, ESD+ was significantly faster in retrograde lesions with a median of 22.5 vs. 34.0 min in 3 cm retrograde lesions (p = 0.002*) and 34.5 vs. 41.0 min (p = 0.011*) in 4 cm retrograde lesions. There were 0 perforations with both techniques. In ESD+ , 1 muscularis damage occurred (3.13%) compared to 6 muscularis damages with ESD (18.75%, p = 0.045*).

Conclusions

By its grasp-and-mobilize technique, ESD+ allows potentially faster and safer resections of flat gastric lesions compared to conventional ESD in an ex vivo porcine model. The potential advantages of ESD+ in terms of procedure time may be particularly relevant for difficult lesions in retrograde positions.

Electronic supplementary material

The online version of this article (10.1007/s00464-020-07808-w) contains supplementary material, which is available to authorized users.

Endoscopic submucosal dissection: an update on tools and accessories

Endoscopic submucosal dissection (ESD) is a minimally invasive therapeutic procedure to remove larger polyps or early non-metastatic lesions. It has long been used in Asia, but is now fast growing in popularity in the West. There are multiple challenges faced by ESD practitioners. While the practice of ESD in gastric lesions is relatively well established, the oesophagus with its narrow lumen and challenging workspace, and the colon with its tortuous course and folds are more challenging frontiers. The nature of performing a procedure endoscopically means that conventional methods offer no mechanism for providing counter-traction while performing dissection, impeding visibility and increasing the rate of complications. There are a multitude of tools available to those performing ESD for the different stages of the procedure. This article reviews the accessories currently used in regular ESD practice including the knives used to cut and dissect lesions, the cap and hood devices used to improve visibility and safety, injection fluids to lift the submucosal plane, haemostatic devices, generators, and finally, emerging traction apparatus. There is some evidence behind the use of these tools, however, ESD remains the domain of a small number of practitioners and the practice relies heavily on expert experience. Evolution of the ESD toolbox will make the procedure more accessible to more endoscopists, which in turn will drive the development of a more substantial evidence base to evaluate efficacy and safety of the multitude of tools.

Improved endoscopic resection of large flat lesions and early cancers using an external additional working channel (AWC): a case series

Background  En-bloc resection of large, flat lesions or early stages of cancer is challenging. No bimanual tasks are possible using standard endoscopes. Dual-channel endoscopes are not available everywhere and have a small distance between the channels. Patients and methods  A new external additional working channel (AWC) (Ovesco, Tuebingen, Germany) was designed and developed potentially enabling bimanual tasks. Fixed to the tip of a standard gastroscope or pediatric colonoscope, a second endoscopic tool can be inserted through the AWC and used for tissue retraction during endoscopic resection. Results  In the upper and lower gastrointestinal tract, endoscopic mucosal resection (EMR) with a modified grasp-and-snare technique and endoscopic submucosal dissection (ESD) were performed successfully using the AWC in eight patients. Complications were acute arterial bleeding post-EMR in two cases treated by endoscopic clipping. Conclusions  We conclude that a newly developed external additional working channel (AWC) enables endoscopic resection of large lesions in the upper and lower gastrointestinal tract. Potential benefits are its suitability for EMR and ESD, no need for a dual-channel endoscope and an adjustable distance of working channels.

Robot assisted tumor resection devices

INTRODUCTION

In Japan, colorectal endoscopic submucosal dissection (ESD) is being conducted safely and effectively as shown by the increased number of the cases, however, it is still regarded as a complicated and challenging procedure. Therefore, piecemeal endoscopic mucosal resection (p-EMR) is still regarded as an appropriate treatment, rather than ESD for large colorectal tumors, especially in Western countries. Areas covered: There are several factors those are responsible for colorectal ESD difficulty. Firstly, there is no adequate traction or counter-traction in colorectal ESD. Secondly, it is challenging to handle the colonoscope in a redundant and narrow colonic lumen. Thirdly, the risk of perforation is estimated to be relatively higher compared to the stomach or esophagus Expert commentary: To overcome these difficulties, various traction and counter-traction methods have been reported and finally, the new concept of the Master and Slave Transluminal Endoscopic Robot (MASTER) has been developed and is soon to be available for clinical use. The authors have reviewed the history of colorectal ESD and MASTER in this paper.

An update in the endoscopic management of gastric cancer

PURPOSE OF REVIEW

Gastric cancer remains a leading cause of mortality worldwide and gastroenterologists are playing an increasingly larger role in its management. This article reviews the endoscopic management of gastric cancer, with emphasis on recent advances in the field.

RECENT FINDINGS

Long-term studies comparing surgery and endoscopic resection for early gastric cancer have shown no difference in 10-year survival rates. Second-look endoscopy, performed 2 days after endoscopic submucosal dissection (ESD) to address the concern of delayed bleeding, may not affect rebleeding rates. Magnesium, proton pump inhibitors, and bupivacaine may help reduce post-ESD pain. New devices such as the Clutch Cutter and EndoLifter may help make ESD easier and safer.

SUMMARY

Endoscopic therapy for early gastric cancer is becoming increasingly popular and innovations are constantly being made to improve technique and technology. This review focuses on the latest approaches to the endoscopic management of gastric cancer.