Advances in traction methods for endoscopic submucosal dissection: What is the best traction method and traction direction?

Animal experimental study on magnetic anchor technique-assisted endoscopic submucosal dissection of early gastric cancer

BACKGROUND

Gastric cancer (GC) has high morbidity and mortality. Moreover, because GC has no typical symptoms in the early stages, most cases are already in the advanced stages by the time the symptoms appear, thus resulting in poor prognosis and a low survival rate. Endoscopic submucosal dissection (ESD) can realize the early detection and diagnosis of GC and become the main surgical method for early GC. However, ESD has a steep learning curve and high technical skill requirements for endoscopists, which is not conducive to its widespread implementation and advancement. Therefore, a series of auxiliary techniques have been derived.

AIM

To evaluate the safety and efficacy of magnetic anchor technique (MAT)-assisted ESD in early GC.

METHODS

This was an ex vivo animal experiment. The experimental models were the isolated stomachs of pigs, which were divided into two groups, namely the study group (n = 6) with MAT-assisted ESD and the control group (n = 6) with traditional ESD. Comparing the total surgical time, incidence of surgical complications, complete mucosal resection rate, specimen size, and the scores of endoscopist’s satisfaction with the procedure reflected their feelings about convenience during the surgical procedure between the two groups. The magnetic anchor device for auxiliary ESD in the study group comprised three parts, an anchor magnet (AM), a target magnet (TM), and a soft tissue clip. Under gastroscopic guidance, the soft tissue clip and the TM were delivered to the pre-marked mucosal lesion through the gastroscopic operating hole. The soft tissue clip and the TM were connected by a thin wire through the TM tail structure. The soft tissue clip was released by manipulating the operating handle of the soft tissue clip in a way that the soft tissue clip and the TM were fixed to the lesion mucosa. In vitro, ESD is aided by maneuvering the AM such that the mucosal dissection surface is exposed.

RESULTS

The total surgical time was shorter in the study group than in the control group (26.57 ± 0.19 vs 29.97 ± 0.28, P < 0.001), and the scores of endoscopist’s satisfaction with the procedure were higher in the study group than in the control group (9.53 ± 0.10 vs 8.00 ± 0.22, P < 0.001). During the operation in the study group, there was no detachment of the soft tissue clip and TM and no mucosal tearing. The magnetic force between the AM and TM provided good mucosal exposure and sufficient tissue tension for ESD. The mucosal lesion was completely peeled off, and the operation was successful. There were no significant differences in the incidence of surgical complications (100% vs 83.3%), complete mucosal resection rate (100% vs 66.7%, P = 0.439), and specimen size (2.44 ± 0.04 cm vs 2.49 ± 0.02, P = 0.328) between the two groups.

CONCLUSION

MAT-ESD is safe and effective for early GC. It provides a preliminary basis for subsequent internal animal experiments and clinical research.

The Role of Specialized Instruments for Advanced Endoscopic Resections in Gastrointestinal Disease

INTRODUCTION

Advanced endoscopic therapy techniques have been developed and have created alternative treatment options to surgical therapy for several gastrointestinal diseases. This work will focus on new endoscopic tools for special indications of advanced endoscopic resections (ER), especially endoscopic submucosal dissection (ESD), which were developed in our institution. This paper aims to analyze these specialized instruments and identify their status.

METHODS

Initially, the technical process of ESD was analyzed, and the following limitations of the different endoscopic steps and the necessary manipulations were determined: the problem of traction-countertraction, the grasping force needed to pull on tissue, the instrument tip maneuverability, the limited angulation/triangulation, and the mobility of the scope and instruments. Five instruments developed by our team were used: the Endo-dissector, additional working channel system, external independent next-to-the-scope grasper, 3D overtube working station, and over-the-scope grasper. The instruments were used and applied according to their special functions in dry lab, experimental in vivo, and clinical conditions by the members of our team.

RESULTS

The Endo-dissector has a two-fold function: (1) grasping submucosal tissue with enough precision and strength to pull it off the surrounding mucosa and muscle, avoiding damage during energy application and (2) effectively dividing tissue using monopolar energy. The AWC system quickly fulfills the lack of a second working channel as needed to complete the endoscopic task on demand. The EINTS grasper can deliver a serious grasping force, which may be necessary for a traction-countertraction situation during endoscopic resection for lifting a larger specimen. The 3D overtube multifunctional platform provides surgical-like work with bimanual-operated instruments at the tip of the scope, which allows for a coordinated approach during lesion treatment. The OTSG is a grasping tool with very special features for cleaning cavities with debris.

CONCLUSIONS

The research and development of instruments with special features can solve unmet needs in advanced endoscopic procedures. The latter may help to increase indications for the endoscopic resections of gut lesions in the future.

Endoscopic Submucosal Dissection of Superficial Colorectal Neoplasms at "Challenging Sites" Using a Double-Balloon Endoluminal Interventional Platform: A Single-Center Study

BACKGROUND

Colonic endoscopic submucosal dissection (ESD) at "challenging sites" such as the cecum, ascending colon, and colonic flexures could be difficult even for expert endoscopists due to poor endoscope stability/maneuverability, steep angles, and thinner wall thickness. A double-balloon endoluminal intervention platform (EIP) has been introduced in the market to fasten and facilitate ESD, particularly when located at difficult sites. Here, we report our initial experience with an EIP comparing the outcomes of an EIP versus standard ESD (S-ESD) at "challenging sites".

MATERIALS AND METHODS

We retrospectively collected data on consecutive patients with colonic lesions located in the right colon and at flexures who underwent ESD in our tertiary referral center between March 2019 and May 2023. Endoscopic and clinical outcomes (technical success, en bloc resection rate, R0 resection rate, procedure time, time to reach the lesion, and adverse events) and 6-month follow-up outcomes were analyzed.

RESULTS

Overall, 139 consecutive patients with lesions located at these challenging sites were enrolled (EIP: 31 and S-ESD: 108). Demographic characteristics did not differ between groups. En bloc resection was achieved in 92.3% and 93.5% of patients, respectively, in the EIP and S-ESD groups. Both groups showed a comparable R0 resection rate (EIP vs. S-ESD: 92.3% vs. 97.2%). In patients undergoing EIP-assisted ESD, the total procedure time was shorter (96.1 [30.6] vs. 113.6 [42.3] minutes, p = 0.01), and the mean size of the resected lesions was smaller (46.2 ± 12.7 vs. 55.7 ± 17.6 mm, p = 0.003). The time to reach the lesion was significantly shorter in the EIP group (1.9 ± 0.3 vs. 8.2 ± 2.7 min, p ≤ 0.01). Procedure speed was comparable between groups (14.9 vs. 16.6 mm2/min, p = 0.29). Lower adverse events were observed in the EIP patients (3.8 vs. 10.2%, p = 0.31).

CONCLUSIONS

EIP allows results that do not differ from S-ESD in the resection of colorectal superficial neoplasms localized in "challenging sites" in terms of efficacy and safety. EIP reduces the time to reach the lesions and may more safely facilitate endoscopic resection.

Two traction methods that can facilitate esophageal endoscopic submucosal dissection

Different traction devices that can provide a visual field and attain appropriate tension at the dissection plane during endoscopic submucosal dissection (ESD) have been developed. Clip-with-line (CWL) is a classic traction device that can offer per-oral traction toward the direction where the line is drawn. A multicenter randomized controlled trial (CONNECT-E trial) comparing the conventional ESD and CWL-assisted ESD (CWL-ESD) for large esophageal tumors was conducted in Japan. This study showed that CWL-ESD was associated with a shorter procedure time (defined as the time from initiating submucosal injection to completing tumor removal) without increasing the risk of adverse events. Multivariate analysis revealed that whole-circumferential lesion and abdominal esophageal lesion were independent risk factors for technical difficulties, which were defined as a procedure time of > 120 min, perforation, piecemeal resection, inadvertent incision (any accidental incision caused by the electrosurgical knife within the marked area), or handover to another operator. Therefore, techniques other than CWL should be considered for these lesions. Several studies have shown the usefulness of endoscopic submucosal tunnel dissection (ESTD) for such lesions. A randomized controlled trial conducted at five Chinese institutions showed that compared with the conventional ESD, ESTD had a significantly reduced median procedure time for lesions covering ≥ 1/2 of the esophageal circumference. In addition, a propensity score matching analysis conducted at a single Chinese institution showed that compared with the conventional ESD, ESTD had a shorter mean resection time for lesions at the esophagogastric junction. With the appropriate use of CWL-ESD and ESTD, esophageal ESD can be performed more efficiently and safely. Moreover, the combination of these two methods may be effective.

Device-assisted traction methods in colorectal endoscopic submucosal dissection and options for difficult cases

Endoscopic submucosal dissection (ESD) procedure has a longer procedure time and higher perforation rate than endoscopic mucosal resection owing to technical complications, including a poor field of vision and inadequate tension for the submucosal dissection plane. Various traction devices were developed to secure the visual field and provide adequate tension for the dissection plane. Two randomized controlled trials demonstrated that traction devices reduce colorectal ESD procedure time compared with conventional ESD (C-ESD), but they had limitations, including a single-center fashion. The CONNECT-C trial was the first multicenter randomized controlled trial comparing the C-ESD and traction device-assisted ESD (T-ESD) for colorectal tumors. In the T-ESD, one of the device-assisted traction methods (S–O clip, clip-with-line, and clip pulley) was chosen according to the operator’s discretion. The median ESD procedure time (primary endpoint) was not significantly different between C-ESD and T-ESD. For lesions ≥ 30 mm in diameter or in cases treated by nonexpert operators, the median ESD procedure time tended to be shorter in T-ESD than in C-ESD. Although T-ESD did not reduce ESD procedure time, the CONNECT-C trial results suggest that T-ESD is effective for larger lesions and nonexpert operators in colorectal ESD. Compared with esophageal and gastric ESD, colorectal ESD has some difficulties, including poor endoscope maneuverability, which may be associated with prolonged ESD procedure time. T-ESD may not effectively improve these issues, but a balloon-assisted endoscope and underwater ESD may be promising options and these methods can be combined with T-ESD.

Endoscopic submucosal dissection techniques and technology: European Society of Gastrointestinal Endoscopy (ESGE) Technical Review

ESGE suggests conventional endoscopic submucosal dissection (ESD; marking and mucosal incision followed by circumferential incision and stepwise submucosal dissection) for most esophageal and gastric lesions. ESGE suggests tunneling ESD for esophageal lesions involving more than two-thirds of the esophageal circumference. ESGE recommends the pocket-creation method for colorectal ESD, at least if traction devices are not used. The use of dedicated ESD knives with size adequate to the location/thickness of the gastrointestinal wall is recommended. It is suggested that isotonic saline or viscous solutions can be used for submucosal injection. ESGE recommends traction methods in esophageal and colorectal ESD and in selected gastric lesions. After gastric ESD, coagulation of visible vessels is recommended, and post-procedural high dose proton pump inhibitor (PPI) (or vonoprazan). ESGE recommends against routine closure of the ESD defect, except in duodenal ESD. ESGE recommends corticosteroids after resection of  > 50 % of the esophageal circumference. The use of carbon dioxide when performing ESD is recommended. ESGE recommends against the performance of second-look endoscopy after ESD. ESGE recommends endoscopy/colonoscopy in the case of significant bleeding (hemodynamic instability, drop in hemoglobin > 2 g/dL, severe ongoing bleeding) to perform endoscopic hemostasis with thermal methods or clipping; hemostatic powders represent rescue therapies. ESGE recommends closure of immediate perforations with clips (through-the-scope or cap-mounted, depending on the size and shape of the perforation), as soon as possible but ideally after securing a good plane for further dissection.

Impact of Traction Direction in Traction-Assisted Gastric Endoscopic Submucosal Dissection (with Videos)

BACKGROUND

The impact of traction direction in traction-assisted gastric endoscopic submucosal dissection (ESD) has not been adequately investigated. A clip with line (CWL) is a classical single-directional traction device. In contrast, a spring and loop with clip (SLC; S-O clip) is a newly developed multidirectional traction device.

AIMS

To investigate the impact of traction direction in gastric ESD by comparing the procedure-related outcomes of CWL-assisted ESD (CWL-ESD) and SLC-assisted ESD (SLC-ESD).

METHODS

We retrospectively examined 140 patients with superficial gastric neoplasms who underwent SLC-ESD or CWL-ESD by a single ESD expert during November 2017-September 2020. The traction direction was classified based on the endoscopic finding in the following five categories: proximal, diagonally proximal, vertical, diagonally distal, and distal. In SLC-ESD, we set vertical traction, using the multidirectional traction function. Propensity score matching was conducted to compensate for the differences in lesion size, injection function of electrosurgical knife, ulcerative lesion, lesion location, and lesion position. The primary outcome was gastric ESD procedure time.

RESULTS

Propensity score matching created 42 pairs. The median gastric ESD procedure time in the SLC-ESD group was significantly shorter than that in the CWL-ESD group (28.3 min vs. 51.0 min, P = 0.022). All traction direction in the SLC-ESD group was vertical, while only 16.7% in the CWL-ESD group. En bloc resection was attained without perforation in all the patients in both groups.

CONCLUSION

Our findings suggest that SLC can provide vertical traction, which reduces the gastric ESD procedure time. Multidirectional traction devices can provide vertical traction in most cases of gastric ESD, unlike single-directional traction devices. Vertical traction may reduce the gastric ESD procedure time.

Use of a novel articulation arm device for endoscopic submucosal dissection of a rectal laterally spreading tumor

Video 1.

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

Background

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

Methods

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

Results

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

Conclusions

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

Building the Toolbox of Devices to Optimize a Practice in Submucosal Endoscopy

Endoscopic submucosal dissection (ESD) is a technically complex and still evolving procedure. As a result, there are many advances in the technology and tools available to assist the endoscopist. This article delves into the various tools developed for ESD including electrosurgical knives, caps, injection agents, and traction devices. The authors discuss tools available as well as their respective pros, cons, and technical considerations for use. Overall, the choice of tools depends on a multitude of factors from availability, cost, lesion characteristics, and the endoscopist's familiarity and proficiency.

A Look into the Future of Endoscopic Submucosal Dissection and Third Space Endoscopy: The Role for Robotics and Other Innovation

Endoscopic resection has been widely applied especially in endoscopic submucosal dissection and third space endoscopy (TSE). Flexible endoluminal robotics allow performance of endoscopic submucosal dissection with exposure of the submucosal plane for precise dissection using two robotic arms. The introduction of TSE revolutionized the horizon of therapeutic endoscopy to the submucosal space beneath and beyond the mucosa. Advantages of TSE include avoidance of full thickness incision in gastrointestinal tract through the submucosal tunneling for performance of peroral endoscopic myotomy and submucosal tunneling endoscopic resection. In future, robotic-driven devices should be developed to enhance performance of complex endoluminal procedures and TSE.

Usefulness of the combined orthodontic rubber band and clip method for gastric endoscopic submucosal dissection

BACKGROUND AND AIMS

Effective traction is an important prerequisite for successful endoscopic submucosal dissection (ESD). The combined orthodontic rubber band (ORB) and clip method was effective in colorectal cancer ESD. To date, the method was not reported in gastric ESD. This study aimed to investigate its efficacy and safety for gastric neoplasms ESD.

METHODS

We retrospectively analyzed data of 118 patients with gastric neoplasms treated by ESD from November 2020 to April 2022, 43 by ORB-ESD and 75 by the conventional ESD. The primary outcome measure was the ESD procedure time. Clinical data on efficacy and safety were also collected and analyzed. Propensity score matching (PSM) matched the patients in both groups.

RESULTS

PSM successfully matched 31 pairs of patients. The ORB-ESD operation time was shorter (median [interquartile range], 35 [30-48] vs. 49 [40-70] min, P < 0.001) and dissection speed was higher (median [interquartile range], 22.6 [14.4-29.3] vs. 13.5 [9.6-17.9] mm²/min, P < 0.001) than in the conventional ESD. The groups were similar in muscular injury rate, frequency and time of use of thermal hemostatic forceps, postoperative adverse events, en bloc resection, and R0 resection rate (P > 0.05).

CONCLUSIONS

Compared to the conventional ESD, ORB-ESD significantly reduced the procedure time and increased the dissection speed, proving beneficial to gastric ESD.

Efficacy and safety of esophageal submucosal tumors treated with internal traction method-assisted submucosal tunneling endoscopic resection: a single-center, single-blind, randomized controlled study

BACKGROUND AND OBJECTIVES

Submucosal tunnel endoscopic resection (STER) is an effective technique for treating esophageal submucosal tumors, but the efficacy and safety of treating esophageal submucosal tumors with internal traction method-assisted STER have not been determined. The objectives of this study were to assess the feasibility, safety, and efficacy of internal traction method-assisted STER for the removal of esophageal submucosal tumors.

PATIENTS AND METHODS

Eighty patients who underwent STER for esophageal submucosal tumors were included in the study. They were randomized and assigned to the two groups. The dual-knife method was used for STER. Forty patients underwent conventional STER (control group) and 40 underwent internal traction method-assisted STER in which self-made rubber band traction with clips was used (study group). In the study group, one end of the self-made rubber band was fixed on the surface of esophageal submucosal tumors with a clip, and the other end of the self-made rubber band was set on the anal side of the contralateral esophageal wall with a clip.

RESULTS

STER was successful in all cases. Lesion features and demographics were similar between the two groups. In addition, broad exposure of the submucosal tissue was obtained by applying tension to the self-made rubber band traction with clips. The en bloc resection rate and complete resection rate were both 100% in the study group. However, the en bloc resection rate and complete resection rate were 85.0% and 100%, respectively, in the control group. Complications, such as perforation and pneumomediastinum, were significantly reduced in the study group, and there was a significant difference in the number of occurrences of bleeding, operation duration, fasting time, and patient length of stay between the study group and control group (P < 0.05). During the mean 13.7 month follow-up, there were no patients with esophageal fistula, recurrence, or distant metastasis in either group.

CONCLUSIONS

This original study showed that esophageal submucosal tumors could be effectively and safely treated with internal traction method-assisted STER, and this technique might be superior to conventional STER due to its fewer complications, shorter operation duration, and shorter inpatient length of stay.

Endoscopic submucosal dissection of appendiceal lesions by using a novel adjustable traction device: A-TRACT-2

Video 1Dissections of appendiceal lesions using A-TRACT-2.

Optimal traction direction in traction-assisted gastric endoscopic submucosal dissection

Various traction devices have been developed to secure a visual field and sufficient tension at the dissection plane during endoscopic submucosal dissection (ESD). However, few large-scale studies have investigated the effectiveness of traction devices in gastric ESD. Clip-with-line (CWL) is one such traction device that is widely used in cases of gastric ESD. The CONNECT-G trial was the first multicenter randomized controlled trial to compare conventional ESD with CWL-assisted ESD (CWL-ESD) for superficial gastric neoplasms. Overall, no significant intergroup difference was observed in terms of the gastric ESD procedure time. However, subgroup analysis according to lesion location revealed a significant reduction in the procedure time of gastric ESD for the lesion located at the greater curvature of the middle and upper third of the stomach in the CWL-ESD group. In this subgroup analysis, lesion location was categorized as follows: anterior wall, posterior wall, lesser curvature, and greater curvature of the upper, middle, and lower thirds of the stomach. However, the gastric ESD procedure time showed no significant difference, except for lesions located at the greater curvature of the upper and middle thirds of the stomach. The traction direction of CWL in the stomach was limited to the cardia and changed depending on the lesion location. Therefore, outcomes of the CONNECT-G trail suggest that the effectiveness of CWL was influenced by lesion location, i.e., traction direction. Further studies are warranted to investigate the optimal traction direction in gastric ESD.

Robotic-assisted vs non-robotic traction techniques in endoscopic submucosal dissection for malignant gastrointestinal lesions

Endoscopic submucosal dissection is an effective approach with higher en bloc resection and complete resection rate for superficial gastrointestinal (GI) lesions. However, endoscopic submucosal dissection is technically challenging and associated with several adverse events, such as bleeding or perforations. The single channel flexible endoscope’s intrinsic limitations in preserving visualization of the submucosal dissection plane as compared to laparoscopic surgery are the most common cause of complications during the endoscopic submucosal dissection technique. As a result, traction techniques were created as the endoscope’s second helping hand in order to improve the effectiveness of the endoscopic submucosal dissection method. Trainees can master endoscopic submucosal dissection methods more quickly by using traction techniques. The anatomical location of the lesion plays a major role in determining which traction technique should be employed. An appealing way of traction is robot-assisted endoscopic submucosal dissection, and various types of endoscopic robots that allow bimanual operation are currently being developed. The advent of robot-assisted endoscopic technology ushers in a new era of endoscopic submucosal dissection, and with it come its own unique challenges that remain to be elucidated. Future research and development efforts are needed to focus on pathways and curriculums for trainees to master the currently available traction techniques and provide avenues for the development of newer traction modalities. In this article, we discuss evolution, characteristics, technological improvements and clinical comparisons of both robotic and non-robotic endoscopic traction techniques used in endoscopic submucosal dissection.