A new technique for endoscopic submucosal dissection for early gastric cancer using an external grasping forceps

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

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

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 efficacy and safety of multi-loop traction device for gastric endoscopic submucosal dissection: a single center prospective pilot study

Although gastric endoscopic submucosal dissection (ESD) is widely used, the degree of difficulty varies greatly depending on the lesion. Since the multi-loop traction device (MLTD) has been suggested to shorten the procedure time in colorectal ESD, we examined the efficacy and safety of using the MLTD in gastric ESD. Thirty patients with gastric neoplasms were prospectively enrolled from February 2022 to December 2022, and the outcomes of ESD with the MLTD were evaluated. The primary outcomes were procedure time and dissection speed. The secondary outcomes were en bloc and R0 resection rates, MLTD attachment time, and complications of ESD with the MLTD. After excluding 1 patient, 29 patients (29 lesions) were treated by ESD with the MLTD. The median procedure time was 26 min (range, 9-210 min), and the median submucosal dissection speed was 39.9 mm2/min (12.4-102.7 mm2/min). The rate of en bloc resection was 100%, the median MLTD attachment time was 3 min (1-7 min), and none of the patients showed intraoperative or postoperative perforations. Thus, gastric ESD with the MLTD showed a favorable procedure time and dissection speed and an acceptable complication rate. Hence, the MLTD may be effective for gastric ESD.

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.

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

PURPOSE

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

METHODS AND METHODS

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

RESULTS

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

CONCLUSIONS

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

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.

Advancing endoscopic traction techniques in endoscopic submucosal dissection

Traction techniques have emerged as a desirable "second-hand" while performing endoscopic submucosal dissection (ESD), enabling adequate visualization of submucosal tissue and vasculature, which allows for safe and efficient dissection. Multiple traction techniques have been developed over the years, and these can be broadly divided into internal and external traction techniques. This arsenal of techniques allows for traction that is personalized to the location of the lesion undergoing ESD. Mastering traction techniques requires structured training, and understanding of the benefits and pitfalls of each technique. Future research and development efforts need to focus on pathways and curriculums for trainees to master the currently available endoscopic traction techniques and provide avenues for the development of newer traction modalities.

Simplified robot-assisted endoscopic submucosal dissection for esophageal and gastric lesions: a randomized controlled porcine study (with videos)

BACKGROUND AND AIMS

Effective countertraction is a main challenging issue in endoscopic submucosal dissection (ESD). Several countertraction methods have been developed to address this issue. The aim of this study was to compare the efficacy of ESD using a novel simplified robot, the flexible auxiliary single-arm transluminal endoscopic robot (FASTER), with a traditional technique.

METHODS

This was a prospective, randomized animal study. Forty-eight ESDs in 6 pigs were carried out at 8 different locations (gastric antrum, gastric body, lower esophagus, and middle esophagus) by the conventional method (n = 24) and by the FASTER-assisted method (n = 24). The primary outcomes were total procedure time, dissection time, and rate of direct-vision dissection. Secondary endpoints were completeness of en-bloc resection and adverse event rate.

RESULTS

The total procedure time was significantly shorter in FASTER-assisted ESD than in conventional ESD (18.8 vs 32.8 minutes; P < .001). In contrast to the median direct-vision dissection rate of 73% with conventional ESD, the FASTER-assisted group had a significantly higher rate of 96% (P < .001). The number of sites of muscular damage was significantly lower using the FASTER-assisted method than the conventional method (6 vs 21, respectively; P = .018). This improvement was more apparent in esophageal lesions compared with gastric lesions.

CONCLUSIONS

This study demonstrated that using a simplified robot during ESD is technically feasible and enables the endoscopist to dynamically use countertraction. This device could significantly reduce procedure time compared with conventional ESD techniques.

The upregulation of circFNDC3B aggravates the recurrence after endoscopic submucosal dissection (ESD) in early gastric cancer (EGC) patients

It has been reported that the expression of CD44 variant 9 could be utilized as a predictive marker for the recurrence in early gastric cancer (EGC) after endoscopic submucosal dissection (ESD). And circFNDC3B was proved to increase the migration and invasion of gastric cancer (GC) cells. In this study, we recruited 96 EGC patients after ESD treatment and grouped them into High circFNDC3B expression group (High expression group) and Low circFNDC3B expression group (Low expression group). Accordingly, we found that the recurrence-free rate in the High expression group was lower than that in the Low expression group. In the High expression group, the relative expression of miR-942 and miR-510 was both suppressed while the relative expression of CDH1 mRNA and CD44 mRNA/protein was increased compared with those in the Low expression group. CircFNDC3B was found to target miR-942 and miR-510 and suppress their expressions respectively. Moreover, miR-942 was found to target CD44 mRNA while miR-510 was found to target CDH1 mRNA. The overexpression of circFNDC3B led to the down-regulation of miR-942 and miR-510, which accordingly resulted in the up-regulation of CD44 and CDH1 in MKN28 cells. Moreover, we found H. pylori infection could promote the expression of circFNDC3B, which also resulted in up-regulated CD44 and CDH1 mRNA level in rTip-α cultivated MKN28 cells. In summary, our study demonstrated that a higher level of circFNDC3B could lead to the increased expression of CD44 and CDH1 via modulating the signaling pathways of miR-942/CD44 and miR-510/CDH1 in EGC patients. And the up-regulation of CD44 and CDH1 would accordingly result in a higher recurrence rate of EGC patients treated by ESD.

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

INTRODUCTION

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

METHODS/DESIGN

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

DISCUSSION

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

TRIAL REGISTRATION

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

PROTOCOL VERSION NUMBER

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

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

Endoscopic submucosal dissection (ESD) has been developed as a treatment for superficial gastrointestinal neoplasms, which can achieve en bloc resection regardless of the lesion size. However, ESD is technically difficult because endoscopists cannot bring their hand into the gastrointestinal tract, unlike surgeons in regular surgery. It is difficult to obtain sufficient tension in the dissection plane and a good field of vision. Therefore, ESD is associated with a long procedure time and a high risk of adverse events in comparison with endoscopic mucosal resection. Traction methods have been developed to provide sufficient tension for the dissection plane and a good field of vision during the ESD procedure. However, traction direction is limited in most traction methods, resulting in insufficient effect in some cases. Although traction direction is considered important, there have been few investigations of its effect. In the first half of this review, important traction methods are discussed, including traction direction. In second half, appropriate traction methods for each organ are considered. Other important considerations for traction method, such as ability to adjust traction strength, interference between traction device and endoscope, and the need for specialized devices are also discussed.

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

Endoscopic submucosal dissection (ESD) has been developed as a treatment for superficial gastrointestinal neoplasms, which can achieve en bloc resection regardless of the lesion size. However, ESD is technically difficult because endoscopists cannot bring their hand into the gastrointestinal tract, unlike surgeons in regular surgery. It is difficult to obtain sufficient tension in the dissection plane and a good field of vision. Therefore, ESD is associated with a long procedure time and a high risk of adverse events in comparison with endoscopic mucosal resection. Traction methods have been developed to provide sufficient tension for the dissection plane and a good field of vision during the ESD procedure. However, traction direction is limited in most traction methods, resulting in insufficient effect in some cases. Although traction direction is considered important, there have been few investigations of its effect. In the first half of this review, important traction methods are discussed, including traction direction. In second half, appropriate traction methods for each organ are considered. Other important considerations for traction method, such as ability to adjust traction strength, interference between traction device and endoscope, and the need for specialized devices are also discussed.

Comparing a conventional and a spring-and-loop with clip traction method of endoscopic submucosal dissection for superficial gastric neoplasms: a randomized controlled trial (with videos)

BACKGROUND AND AIMS

Several traction methods have sought to overcome the technical difficulties of endoscopic submucosal dissection (ESD). However, traction direction has remained limited in most of these methods, with lack of clarity about the optimal method and traction direction for gastric ESD. A spring-and-loop with clip (SLC) has been developed as a multidirectional traction device. Here, we investigated whether SLC traction-assisted ESD (SLC-ESD) improved procedure-related outcomes compared with conventional ESD (C-ESD) among patients with superficial gastric neoplasms.

METHODS

This single-center randomized controlled trial included patients with superficial gastric neoplasms undergoing SLC-ESD or C-ESD between October 2018 and December 2019. Using the multidirectional traction function, we set traction vertical to the gastric wall for SLC-ESD. The primary outcome was the median procedure time for gastric ESD.

RESULTS

The SLC-ESD and C-ESD groups comprised 40 patients each, and all the enrolled patients underwent the assigned treatment. The median ESD procedure time was significantly shorter in the SLC-ESD group (29.1 minutes) than in the C-ESD group (52.6 minutes; P = .005). SLC had a mean attachment time of 1.82 minutes. En bloc resection was achieved without perforation in all the patients in both groups.

CONCLUSIONS

Our findings suggest that SLC-ESD reduces gastric ESD procedure time without increasing the risk of perforation and that the vertical direction to the gastric wall is the appropriate traction direction for gastric ESD. (Clinical trial registration number: UMIN 000034533.).

Simplified magnetic anchor-guided endoscopic submucosal dissection: an ex vivo porcine model

INTRODUCTION AND AIMS

Endoscopic submucosal dissection (ESD) is a well-established treatment for superficial gastrointestinal tumors and enables en bloc resection. Adequate tissue tension is important for safe and effective dissection. Simplified magnetic anchor-guided ESD (MAG-ESD) with a neodymium magnet has potential benefits, compared with other current traction methods. We evaluated the feasibility of simplified MAG-ESD in an ex vivo porcine model.

MATERIALS AND METHODS

An experimental study was conducted, utilizing the standard ESD technique. An external magnet and an internal magnet, both neodymium magnets, were used for the magnetic anchoring. The internal magnet was attached to an arm of a hemoclip with a 2-0 silk suture. After the incision, the clip with the internal magnet was placed at the edge of the lesion. The external magnet was maneuvered around the surface to apply adequate tension.

RESULTS

A total of 15 en bloc ESDs (five with no magnetic anchoring and 10 with magnetic anchoring) were carried out. Traction and dissection were feasible in all cases and the procedures were completed in fewer than 90 min. Lesion size ranged from 15 to 50 mm (mean 30 mm). Two cases in the group with magnetic anchoring presented with punctate perforation (13.3%).

CONCLUSIONS

Our study demonstrated the feasibility of simplified MAG-ESD and en bloc resection in an ex vivo porcine model.

Innovative therapeutic endoscopy in the upper gastrointestinal tract: Review of Japan Gastroenterological Endoscopic Society Core Sessions

Workshops on "Innovative Therapeutic Endoscopy" for upper gastrointestinal tract diseases were held four times as the Japan Gastroenterological Endoscopic Society (JGES) Core Sessions at the 93rd to 96th Biannual Meetings of the JGES. A total of 48 research presentations (including two invited lectures) were reported, and various discussions were held on these topics. When the research presentations were categorized according to the therapeutic procedure, endoscopic submucosal dissection (ESD) was the most frequent with 28 presentations (58.3%), followed by laparoscopy endoscopy cooperative surgery (LECS) with six presentations (12.5%). When the research presentations were classified by the target organ of the therapeutic procedures, the duodenum was the most frequent with 26 presentations (54.1%), followed by the stomach with 13 presentations (27.1%). The most important issue was the establishment of a safe and reliable endoscopic resection method for duodenal lesions. Issues related to gastric ESD were establishing an efficient traction method and a method to prevent post-ESD bleeding in high-risk patients. Other important issues were establishment of an efficient traction method and methods of preventing delayed bleeding in high-risk patients who undergo gastric ESD, expansion of indications for minimally invasive treatment using LECS for gastric cancer, the development of endoscopic full-thickness resection (EFTR) for gastric submucosal tumors (SMTs), and improvement of per-oral endoscopic myotomy (POEM) for esophageal achalasia and per-oral endoscopic tumor resection (POET) for esophageal SMTs. Through the JGES Core Sessions, it is expected that the minimally invasive treatments using endoscopes developed in Japan will be further advanced.

Usefulness of the flexible traction method in gastric endoscopic submucosal dissection: an in-vivo animal study

BACKGROUND

An appropriate traction of the target lesion is a key for a safe and secure ESD procedure. We proposed the flexible traction method (F-trac) which provided an optimal traction using an endoscopic hand-suturing (EHS) and investigated the usefulness of this technique for gastric ESD in-vivo porcine model.

METHODS

In the F-trac method, a lesion was suspended by pulling proximal side of endoscope which was connected to the contralateral side with a barbed suture using the EHS technique just before starting the submucosal dissection. A single endoscopist performed conventional ESD (C-ESD) and F-trac ESD alternately for a total of ten simulating lesions of 3 cm in diameter in a live porcine stomach. The pig was rotated so that each lesion was positioned in the direction of the gravity. The procedure time, technical accuracy, adverse events, and the number of additional injection to the submucosal layer during dissection were evaluated.

RESULTS

The total ESD procedure time in the F-trac group was significantly shorter than in C-ESD group (19.0 min vs. 30.6 min, p = 0.039). There were no significant differences between both groups in muscular layer damage, sample damage, perforation, and intraoperative bleeding. The number of additional injection in the F-trac group was significantly fewer than that in C-ESD group (0 times vs. 4.4 times, p = 0.027).

CONCLUSIONS

In gastric ESD, F-trac might be useful for shortening the total procedure time. This method can facilitate optimal traction without disturbing the endoscopic visualization and the movement of endoscope.

EMR/ESD: Techniques, Complications, and Evidence

PURPOSE OF REVIEW

To discuss endoscopic resection techniques of early gastrointestinal malignancy. The review will focus on the indications and outcomes of endoscopic mucosal resection (EMR) and endoscopic submucosal dissection (ESD).

RECENT FINDINGS

EMR is indicated for upper GI lesions less than 20 mm provided they can be easily lifted and have a low risk of submucosal invasion (SMI). ESD should be considered for esophageal and gastric lesions that are bulky, show intramucosal carcinoma, or have a risk of superficial submucosal invasion. With regard to colonic polyps, EMR is acceptable for the removal of large colonic polyps using a piecemeal technique. ESD can be reserved for rectal neuroendocrine tumors, fibrotic polyps, or polyps harboring early malignancy. In selected cases, particularly in lesions less than 2 cm in size, EMR can be safe and effective. For larger lesions or lesions with submucosal invasion, ESD is effective and curative. Choosing the best approach can be tailored for each patient depending on lesion size, pathology, and availability of local expertise.

Comparable Data Between Double Endoscopic Intraluminal Operation and Conventional Endoscopic Submucosal Dissection for Esophageal Cancer

BACKGROUND

Endoscopic submucosal dissection (ESD) of superficial esophageal cancer has been used increasingly as an alternative to surgery because it is minimally invasive and has a high rate of en bloc resection. We previously reported that the double endoscopic intraluminal operation (DEILO) is a useful technique for ESD of early esophageal cancers. In the current study, we showed comparable short-term data between DEILO and conventional ESD groups to demonstrate the further advanced use of DEILO.

METHODS

We studied 111 esophageal cancer patients with 111 lesions treated using endoscopic surgery between January 2010 and June 2016 at Gunma University Hospital. Of the patients, 51 underwent DEILO (DEILO group) and 60 underwent conventional ESD (ESD group). We compared the operable performance, complications, and pathological outcome between the ESD and DEILO groups.

RESULTS

There was no significant difference in operable performance. However, the DEILO group showed a significantly lower rate of mediastinal emphysema compared to the ESD group (p = 0.025). Overall, the DEILO group showed a lower complication rate compared to the ESD group, although there was no apparent significance.

CONCLUSION

To our knowledge, this is the first report comparing DEILO and conventional ESD for esophageal cancer. The results showed that DEILO is not inferior to conventional ESD. DEILO is an excellent endoscopic surgical method, although it has some limitations compared to conventional ESD.

Efficacy and safety of endoscopic submucosal dissection for large gastric stromal tumors

BACKGROUND AND AIM

Endoscopic submucosal dissection (ESD) of gastric stromal tumors is becoming increasingly common. However, there have been few studies analyzing the therapeutic efficacy and safety of this technique on large (≥ 3 cm) gastric stromal tumors (LGSTs). The aim of this study was to determine the feasibility of ESD for the removal of LGSTs and to investigate the clinical safety and efficacy of ESD for this indication.

METHODS

A retrospective analysis was carried out on 82 patients with LGSTs who underwent an ESD. Data on therapeutic outcomes and follow-up were collected for an analysis of the rates of en block resection and complete resection. A logistic regression model was used to identify potential risk factors for ESD-related complications, and a receiver operating characteristic (ROC) curve was generated for qualifying independent risk factors.

RESULTS

En bloc resection was achieved in 81 lesions (98.8%), and complete resection was achieved in 80 lesions (97.6%). The rates of intraoperative and postoperative bleeding were 6.1% and 3.7%, respectively. The accidental perforation rate was 12.2%, the postoperative perforation rate was 3.7%, the intentional perforation rate was 28.0%, and the postoperative infection rate was 12.2%. There was no postoperative mortality. LGSTs originating from the deep muscularis propria (MP) layer (OR = 4.905, 95% CI: 1.362-17.658, P = 0.015), located at the gastric fundus (OR = 4.927, 95% CI:1.308-18.558, P = 0.018) and with an irregular shape (OR = 4.842, 95% CI: 1.242-18.870, P = 0.023) increased the rate of complications. The prediction model that incorporated these factors demonstrated an area under the ROC curve of 0.77 (95% CI: 0.66-0.89). No tumor recurrence or distant metastasis was observed during the follow-up period, which ranged from 6-36 months.

CONCLUSIONS

ESD is a feasible, safe, effective and minimally invasive approach for the resection of LGSTs. Tumors originating from the deep MP layer, located at the fundus and with an irregular shape were identified as risk factors for the development of complications.

Endoscopic submucosal dissection of distal intestinal tumors using grasping forceps for traction

BACKGROUND

The aim of this study was to assess the efficacy of traction device-assisted endoscopic submucosal dissection (ESD) of the rectum and the distal segment of sigmoid colon using grasping forceps.

METHODS

A total of 43 patients scheduled for colonic ESD at our institution were enrolled between January 2013 and June 2017. The patients were randomly allocated to receive conventional ESD (group A) or traction device-assisted ESD (group B). The procedure time, complication rate, and en-block resection rate in the two groups were compared.

RESULTS

A total of 41 patients completed the study. The procedure time, complication rate and en-block resection rate were, respectively, 104.1 ± 34.7 min, 15%, 90% in the routine group (group A) and 84.7 ± 23.5 min, 9.5%, 90.5% in traction device-assisted ESD (group B). The procedure time in group B was significantly less than that in group A (F = 4.442, p < 0.05).

CONCLUSIONS

Traction device-assisted ESD using grasping forceps is safe and effective in distal colon ESD.

Short-term outcomes of traction-assisted versus conventional endoscopic submucosal dissection for superficial gastrointestinal neoplasms: a systematic review and meta-analysis of randomized controlled studies

Background

In recent years, some traction-assisted approaches have been introduced to facilitate endoscopic submucosal dissection (ESD) procedures by reducing the procedure time and risks related to the procedure. However, the relative advantages of traction-assisted endoscopic submucosal dissection (T-ESD) are still being debated. This study aimed to assess the efficacy of T-ESD for the treatment of superficial gastrointestinal neoplasms.

Methods

We searched MEDLINE, Embase, and Cochrane library up to March 31, 2019 for randomized controlled trials (RCTs) comparing T-ESD and conventional endoscopic submucosal dissection (C-ESD) for superficial gastrointestinal neoplasms. The main endpoints are en bloc resection, complete resection, procedure time, perforation, and delayed bleeding. Pooled risk ratio (RR), Peto odds ratio (OR), and mean difference (MD) were calculated to compare T-ESD and C-ESD. This study is registered with PROSPERO, number CRD42018108135.

Results

A total of 7 RCTs with 1007 patients were included in this meta-analysis. There were no significant differences between the T-ESD and C-ESD groups in the pooled estimate of en bloc resection, complete resection, and delayed bleeding (RR = 1.00, 95% CI 0.99, 1.01, I² = 0%, P = 0.66; RR = 1.00, 95% CI 0.98, 1.03, I² = 0%, P = 0.81; OR = 0.95, 95% CI 0.48, 1.86, I² = 19%, P = 0.87,respectively). The pooled estimate indicated that the procedure time was significantly shorter in the T-ESD group (MD = − 16.19, 95% CI − 29.24, − 3.13, I² = 87%, P = 0.02) than in the C-ESD group. Compared to C-ESD, T-ESD was associated with lower incidence of perforation (OR = 0.32, 95% CI 0.11, 0.91, I² = 0%, P = 0.03).

Conclusions

T-ESD is a safe and effective treatment option with a low perforation rate and shorter procedure time than C-ESD for superficial gastrointestinal neoplasms. Future multi-center (including European populations), randomized controlled trials of larger sample size and long-term outcomes of T-ESD are required.

Snare combined with endoclips in endoscopic submucosal dissection with mucosal traction for gastroesophageal neoplasia

BACKGROUND AND AIM

Mucosal traction as a "second hand" in endoscopic submucosal dissection (ESD) is very helpful for ESD operators. The efficacy of using a snare combined with endoclips to assist in ESD (SC-ESD) was evaluated whether it could achieve peroral external traction (PET) and peroral internal traction (PIT) and real-time adjustment of mucosal traction position. This study aimed to preliminarily evaluate its feasibility.

METHODS

A snare was fixed using endoclips to the incised mucosal flap that was intended for dissection. Subsequently, the snare was adjusted to achieve mucosal traction. This study included 54 gastroesophageal neoplasias in 54 consecutive patients who underwent SC-ESD. The operative and clinical data were retrospectively collected.

RESULTS

Peroral external tractions were performed for 22 esophageal neoplasias, and PETs and PITs were performed for 32 gastric neoplasias. The median (interquartile range) sizes of lesions were 4.3 (2.5) and 4.2 (2.1) cm, operation times were 73.4 (43.8) and 60.0 (45.2) min, and submucosal dissection times were 27.0 (32.0) and 31.0 (34.5) min in the esophagus and stomach, respectively. Mucosal traction position could be effectively adjusted by fixing the snare to the incised mucosal flap intended for dissection during SC-ESD. All lesions in the esophagus and stomach were completely resected, with R0 resection rates of 100%. Besides postoperative bleeding in a patient with gastric neoplasia, no intraoperative and postoperative perforations occurred.

CONCLUSIONS

SC-ESD seems to be feasible for resecting gastroesophageal neoplasia, and two types of mucosal tractions (PET and PIT) could be effectively achieved during SC-ESD. Further prospective comparative study with a large sample is warranted.

An internal magnet traction device reduces procedure time for endoscopic submucosal dissection by expert and non-expert endoscopists: ex vivo study in a porcine colorectal model (with video)

BACKGROUND

Efficacy of an internal magnet traction device (MTD) for gastric endoscopic submucosal dissection (ESD) by an expert endoscopist has been reported. We hypothesized that use of the MTD would enhance the performance of colorectal ESD in a non-expert endoscopist in ESD compared to the conventional technique. Primary aim of this study was to compare procedure times between conventional ESD (C-ESD) and MTD-assisted ESD (MTD-ESD) by expert and non-expert endoscopists in ESD. Secondary aims included rate of en bloc resection, iatrogenic injury, visualization score of the submucosal layer, and endoscopist satisfaction score.

METHODS

A total of 56 lesions were created in an ex vivo porcine colorectum. Two endoscopists completed C-ESD (n = 28) and MTD-ESD (n = 28). Lesions measured 3 cm in diameter and were located on either the anterior or posterior colorectal wall. The MTD consisted of a small neodymium magnet and nylon monofilament attached to a through-the-scope clip. The first MTD was deployed on the opposing colorectal wall of the target lesion and a second MTD was then deployed directly onto the distal margin of the lesion.

RESULTS

Total procedure time for MTD-ESD was significantly shorter than C-ESD for both expert (median: 15.8 vs. 19.3 min, p < 0.05) and non-expert (median: 21.3 vs. 33.9 min, p < 0.001) endoscopists. All lesions were resected en bloc. There was no iatrogenic muscularis propria injury in the MTD-ESD group. For both the expert and non-expert, scores for MTD-ESD were significantly higher for submucosal layer visualization (p < 0.05) and endoscopist satisfaction (p < 0.001) compared to C-ESD.

CONCLUSIONS

Use of the MTD significantly reduced procedure time for both expert and non-expert endoscopists performing ESD. Improving the efficiency, safety, and satisfaction of ESD with such a device particularly for non-expert endoscopists is appealing and could potentially minimize the complexity and duration of the procedure allowing for more widespread use of the technique.

Efficacy and safety of an internal magnet traction device for endoscopic submucosal dissection: ex vivo study in a porcine model (with video)

BACKGROUND

Appropriate traction allows for safer and easier endoscopic submucosal dissection (ESD). The aim of this study was to evaluate the efficacy and safety of an internal magnet traction device (MTD) for ESD in an ex vivo porcine model.

METHODS

The MTD consisted of a small neodymium magnet and a suture attached to a through-the-scope clip. A circumferential mucosal incision was completed around a 30-mm diameter template that served as the target lesion. The first MTD was deployed at the proximal edge of the lesion. A second MTD was deployed on the wall opposite the lesion. With both magnets connected, this created traction or lifting of the target lesion towards the opposing wall during submucosal dissection. Primary endpoint was comparison of submucosal dissection times between conventional ESD (C-ESD) and MTD-assisted ESD (MTD-ESD).

RESULTS

Twenty lesions along the anterior wall, posterior wall and greater curvature were resected using either C-ESD or MTD-ESD. The submucosal dissection time in MTD-ESD was significantly shorter than C-ESD (median: 6.4 [interquartile range {IQR} 4.6-8.7] min vs. 14.4 min [IQR 11.8-18.0], p < 0.05). There was a significant difference between MTD-ESD and C-ESD in total procedure times for lesions on the posterior gastric wall and greater curvature (median: 23.0 min [IQR 21.1-24.5] vs. 29.2 min [IQR 24.8-33.2], p < 0.05) with no difference for lesions on the anterior gastric wall (median: 18.8 min [IQR 15.5-20.5] vs. 17.1 min [IQR 13.1-20.0], p = 0.5). The number of muscularis propria injuries per lesion was significantly lower in MTD-ESD than C-ESD (median: 0 [IQR 0-0] vs. 1 [IQR 0-2], p < 0.05).

CONCLUSIONS

MTD for ESD is effective and safe when compared to C-ESD. This approach significantly reduced submucosal dissection times with less injury to the muscularis propria. Furthermore, MTD-ESD was particularly beneficial for more challenging gastric lesions located on the posterior wall and greater curvature.

Magnetic anchor-guided endoscopic submucosal dissection for gastric lesions (with video)

BACKGROUND AND AIMS

The feasibility of magnetic anchor-guided endoscopic submucosal dissection (MAG-ESD) using a neodymium magnet for gastric lesions has not been clarified. The aim of study was to evaluate the feasibility of MAG-ESD using neodymium magnets while treating gastric lesions.

METHODS

This prospective trial was conducted at the Yamashita Hospital. MAG-ESD was performed for 50 gastric lesions using an insulated-tip knife. The magnetic anchor consisted of an internal neodymium magnet attached to a hemoclip with 3-0 silk. The external and internal magnets were made from the neodymium magnet. The feasibility of traction using MAG-ESD, en bloc resection rate, complete en bloc resection rate, time required for preparation and attaching the magnetic anchor, procedure time, rate of retrieval of the magnetic anchors, and adverse events were evaluated.

RESULTS

Fifty patients (median lesion size, 20 mm [range, 5-100]) were enrolled. MAG-ESDs were successfully performed for all 50 gastric lesions. Adequate counter-traction was obtained using the external magnet. En bloc resections were achieved and complete en bloc resections confirmed in all cases without adverse events. Attaching the magnetic anchor required a median of 6 minutes (range, 2-14). The median procedure time was 49 minutes (range, 15-301), and the magnetic anchors could be retrieved in all cases.

CONCLUSIONS

This study clearly demonstrated the feasibility of this MAG-ESD in the stomach. We hope this procedure will facilitate the resection of difficult lesions. (Clinical trial registration number: UMIN000024100.).

Conventional versus traction-assisted endoscopic submucosal dissection for gastric neoplasms: a multicenter, randomized controlled trial (with video)

BACKGROUND AND AIMS

The aim of this study was to clarify whether dental floss clip (DFC) traction improves the technical outcomes of endoscopic submucosal dissection (ESD).

METHODS

A superiority, randomized control trial was conducted at 14 institutions across Japan. Patients with single gastric neoplasm meeting the indications of the Japanese guidelines for gastric treatment were enrolled and assigned to receive conventional ESD or DFC traction-assisted ESD (DFC-ESD). Randomization was performed according to a computer-generated random sequence with stratification by institution, tumor location, tumor size, and operator experience. The primary endpoint was ESD procedure time, defined as the time from the start of the submucosal injection to the end of the tumor removal procedure.

RESULTS

Between July 2015 and September 2016, 640 patients underwent randomization. Of these, 316 patients who underwent conventional ESD and 319 patients who underwent DFC-ESD were included in our analysis. The mean ESD procedure time was 60.7 and 58.1 minutes for conventional ESD and DFC-ESD, respectively (P = .45). Perforation was less frequent in the DFC-ESD group (2.2% vs .3%, P = .04). For lesions located in the greater curvature of the upper or middle stomach, the mean procedure time was significantly shorter in the DFC-ESD group (104.1 vs 57.2 minutes, P = .01).

CONCLUSIONS

Our findings suggest that DFC-ESD does not result in shorter procedure time in the overall patient population, but it can reduce the risk of perforation. When selectively applied to lesions located in the greater curvature of the upper or middle stomach, DFC-ESD provides a remarkable reduction in procedure time.

Endoscopic Submucosal Tunnel Dissection for Large Gastric Neoplastic Lesions: A Case-Matched Controlled Study

Aim

To evaluate the efficacy and safety of endoscopic submucosal tunnel dissection (ESTD) for resection of large superficial gastric lesions (SGLs).

Methods

The clinicopathological records of patients performed with ESTD or endoscopic submucosal dissection (ESD) for SGLs between January 2012 and January 2014 were retrospectively reviewed. 7 cases undergoing ESTD were enrolled to form the ESTD group. The cases were individually matched at a 1 : 1 ratio to other patients performed with ESD according to lesion location, ulcer or scar findings, resected specimen area, operation time and operators, and the matched cases constituting the ESD group. The treatment outcomes were compared between the two groups.

Results

The mean specimen size was 46 mm. 10 lesions were located in the cardia and 4 lesions in the lesser curvature of the lower gastric body. En bloc resection was achieved for all lesions. The mean ESTD resection time was 69 minutes as against 87.7 minutes for the ESD (P = 0.01). The mean resection speed was faster for ESTD than for ESD (18.86 mm²/min versus 13.76 mm²/min, P = 0.03). There were no significant differences regarding the safety and curability during the endoscopic follow-up (mean 27 months).

Conclusions

ESTD is effective and safe for the removal of SGLs and appears to be an optimal option for patients with large SGLs at suitable sites.

Recent Development of Techniques and Devices in Colorectal Endoscopic Submucosal Dissection

Colorectal endoscopic submucosal dissection (ESD) is now a well-established endoscopic treatment for early-stage colorectal neoplasms, especially in Asian countries, including Japan. Despite the spread of colorectal ESD, there are still situations in which achieving successful submucosal dissection is difficult. Various novel techniques and devices have been developed to overcome these difficulties, and past reports have shown that some of these strategies can be applied to colorectal ESD. We review several recent developments in the field. The techniques reviewed include the pocket creation method and traction methods and the devices reviewed include the overtube with balloon and electrosurgical knives with water-jet function. These improved techniques and devices can facilitate safer, more reliable ESDs and expand its applicability and acceptability all over the world.

MicroRNA‑499 rs3746444 A/G polymorphism functions as a biomarker to predict recurrence following endoscopic submucosal dissection in primary early gastric cancer

The aim of the present study was to investigate the molecular mechanism, including the potential regulatory and signaling pathways, of platelet‑derived growth factor receptor β (PDGFRB), which underlies the recurrence of early gastric cancer (EGC) following endoscopic submucosal dissection (ESD). Online microRNA (miRNA) target prediction tools were used, which identified PDGFRB as the candidate target gene of miR‑499a in gastric cancer cells, and PFGRBR was then confirmed as the direct gene using a luciferase reporter assay system. The Kaplan‑Meier method was used to plot recurrence‑free curves, which were compared between genotype groups. A negative regulatory association between miR‑499a and PDGFRB was established by investigating the relative luciferase activity at different concentrations of miR‑499a mimics. Furthermore, as the rs3746444 polymorphism has been previously reported to interfere with the expression of miR‑499a, the present study investigated the expression levels of different genotypes, including TT (n=20), TC (n=9) and CC (n=3), the results of which supported the hypothesis that the presence of the minor allele (C) of the rs3746444 polymorphism compromised the expression of miR‑499a. The present study also performed polymerase chain reaction and western blot analyses to examine the mRNA and protein expression levels of PFGRBR among different genotypes or cells treated with different concentrations of miR‑499a mimics/inhibitors, which indicated the negative regulatory association between miR‑499a and PDGFRB. The present study also investigated the relative viabilities of EGC cells transfected with miR‑499a mimics (50 and 100 nM) and miR‑499a inhibitors (100 nM), and confirmed that miR‑499a negatively interfered with the viability of the EGC cells. The miR‑499a rs3746444 polymorphism was also recognized as a biomarker to predict recurrence following ESD in patients with EGC via analyzing the recurrence‑free rates among patients with EGC with different genotypes. The results showed that PDGFRB was validated as a target of miR‑499a, and rs3746444 was identified as a potential biomarker to predict the recurrence of EGC following ESD.

Effectiveness of clip-and-snare method using pre-looping technique for gastric endoscopic submucosal dissection

AIM: To evaluate efficacy and safety of clip-and-snare method using pre-looping technique (CSM-PLT) for gastric endoscopic submucosal dissection (ESD).

METHODS: In the CSM-PLT method, a clip attached to the lesion side was strangulated with a snare, followed by application of an appropriate tension to the lesion independent of an endoscope. Twenty consecutive lesions were resected by ESD using CSM-PLT (CSM-PLT group) and compared with a control group, including 20 lesions that were resected by conventional ESD. The control group was matched based on the size and location of the lesion, presence of pathologic fibrosis, and experience of endoscopists. Total procedure time of ESD, proportion of en bloc resection, and complications were analyzed.

RESULTS: The total procedure time for the CSM-PLT group was significantly shorter than that for the control group (38.5 min vs 59.5 min, P = 0.023); all lesions were resected en bloc by ESD. There was no significant difference in complications between the two groups. Moreover, there was no complication in the CSM-PLT group. In one large lesion (size: 74 mm) that underwent extensive CSM-PLT during ESD, we used an additional CSM-PLT on another edge of the lesion after achieving submucosal resection to the maximum extent possible during initial CSM-PLT. In two lesions, the snare came off the lesion together with the clip after a sudden pull; nevertheless, ESD was successful in all lesions.

CONCLUSION: CSM-PLT was an effective and safe method for gastric ESD.

Application of robotics in gastrointestinal endoscopy: A review

Multiple robotic flexible endoscope platforms have been developed based on cross specialty collaboration between engineers and medical doctors. However, significant number of these platforms have been developed for the natural orifice transluminal endoscopic surgery paradigm. Increasing amount of evidence suggest the focus of development should be placed on advanced endolumenal procedures such as endoscopic submucosal dissection instead. A thorough literature analysis was performed to assess the current status of robotic flexible endoscopic platforms designed for advanced endolumenal procedures. Current efforts are mainly focused on robotic locomotion and robotic instrument control. In the future, advances in actuation and servoing technology, optical analysis, augmented reality and wireless power transmission technology will no doubt further advance the field of robotic endoscopy. Globally, health systems have become increasingly budget conscious; widespread acceptance of robotic endoscopy will depend on careful design to ensure its delivery of a cost effective service.

Usefulness of a traction method using dental floss and a hemoclip for gastric endoscopic submucosal dissection: a propensity score matching analysis (with videos)

BACKGROUND AND AIMS

Although endoscopic submucosal dissection (ESD) is a significant advancement in therapeutic endoscopy, it is a complicated technique and requires considerable expertise. In this exploratory study, we evaluated the efficacy of a simple traction method that uses dental floss and a hemoclip (DFC) and was developed to overcome the technical difficulties of ESD.

METHODS

In total, 238 early gastric cancers treated by ESD between May 2012 and December 2014 at Tokyo Medical University were retrospectively reviewed. Lesions treated by conventional ESD (n = 185) and by ESD with DFC (ESD-DFC) (n = 53) were compared. Multivariable analyses and propensity score matching were used to compensate for the differences in age, sex, resected specimen size, lesion location, lesion position, presence of ulceration, and operator level. The procedure time, rate of en bloc and complete resection, and rates of adverse events were evaluated between the 2 groups.

RESULTS

Propensity score matching analysis created 43 matched pairs. Adjusted comparisons between ESD-DFC and conventional ESD showed similar treatment outcomes (en bloc resection rate: 97.7% vs 100%, P = .315; complete resection rate: 90.7% vs 95.3%, P = .397; perforation during ESD rate: 2.3% vs 2.3%, P = 1.000; post-ESD bleeding rate: 4.7% vs 4.7%, P = 1.000) but a significantly shorter procedure time for ESD-DFC (82.2 ± 79.5 minutes vs 118.2 ± 71.6 minutes, P = .002).

CONCLUSION

ESD-DFC facilitated rapid ESD with good visualization and traction while ensuring high curability and safety.

Thread-Traction with a Sheath of Polypectomy Snare Facilitates Endoscopic Submucosal Dissection of Early Gastric Cancers

Although the thread-traction (TT) method has been found useful during endoscopic submucosal dissection (ESD) for early gastric cancers, the movement of the thread interferes with the movement of the endoscope, and the lesion can only be pulled to the mouth side. We have developed the novel TT method using a sheath of polypectomy snare (TTSPS). The TTSPS method enables free and independent movement of the thread and the endoscope and allows pulling the lesion towards the anal as well as oral side. The median dissection times, numbers of instances of arterial bleeding, and numbers of local injections into the submucosal layer were significantly lower for ESD with TTSPS than for conventional ESD. Countertraction ESD using the TTSPS method is straightforward, safe, easy, noninvasive, and cost effective, and it uses instruments readily available in most hospitals to enhance visualization of cutting lines. Therefore, the TTSPS method can be universally applied in conventional ESD.

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

Background/Aims

To investigate whether the EndoLifter (Olympus), a counter-traction device facilitating submucosal dissection, can accelerate endoscopic submucosal dissection (ESD).

Methods

Two endoscopists (novice/expert in ESD) performed 64 ESDs (artificial 3-cm lesions) in 16 ex vivo pig stomachs: per stomach, two at the posterior wall (forward approach) and two at the lesser curvature (retroflex approach). Per approach, one lesion was dissected with (EL+) and one without (EL-) the EndoLifter. The submucosal dissection time (SDT), corrected for specimen size, and the influence of ESD experience on EndoLifter usefulness were assessed.

Results

En bloc resection rate was 98.4%. In the forward approach, the median SDT was shorter with the EndoLifter (0.56 min/cm² vs. 0.91 min/cm²), although not significantly (p=0.09). The ESD-experienced endoscopist benefitted more from the EndoLifter (0.45 [EL+] min/cm² vs. 0.68 [EL-] min/cm², p=0.07) than the ESD-inexperienced endoscopist (0.77 [EL+] min/cm² vs. 1.01 [EL-] min/cm², p=0.48). In the retroflex approach, the median SDTs were 1.06 (EL+) and 0.48 (EL-) min/cm² (p=0.16). The EndoLifter did not shorten the SDT for the ESD-experienced endoscopist (0.68 [EL+] min/cm² vs. 0.68 [EL-] min/cm², p=0.78), whereas the ESD-inexperienced endoscopist seemed hindered (1.65 [EL+] min/cm² vs. 0.38 [EL-] min/cm², p=0.03).

Conclusions

In gastric ESD, the EndoLifter, in trend, shortens SDTs in the forward, but not in the retroflex approach. Given the low numbers in this study, a type II error cannot be excluded.

East Meets West-A Novel Steerable Grasper to Facilitate Gastric Endoscopic Submucosal Dissection (ESD): Randomized Comparative Study in a Porcine Model

BACKGROUND

Endoscopic submucosal dissection (ESD) is challenging because of the limited ability of conventional endoscopic tools to achieve adequate traction. We have recently used a novel steerable grasper (SG; ANUBIS grasper, Karl Storz, Tüttlingen, Germany) with intuitive manipulating handles to lift up the mucosa. The aim of this study is to evaluate the efficacy of the assistance of the SG in a porcine acute model.

MATERIALS AND METHODS

A total of 36 gastric ESDs were performed in 12 swine (3 ESDs/pig), at the antrum, greater curvature of the gastric body, and cardia. Pigs were randomly assigned to the SG group (n = 6) or to the control group (n = 6). ESD steps included the following: scoring the area, submucosal injection, and precut and submucosal dissection with or without SG assistance. Outcomes measured were as follows: dissection time, dissection speed, size of specimen, completeness of dissection (all marks included in the specimen), en bloc dissection, and complications.

RESULTS

Overall mean dissection time was 18.6 ± 7.56 versus 29 ± 18.14 minutes (P = .032), and mean dissection speed was 94.74 ± 39.74 mm(2)/min versus 65.41 ± 39.5 mm(2)/min (P = .033) in the SG and control groups, respectively. Mean size of the specimen was 1451.4 ± 549.2 mm(2) in the SG group and 1615.3 ± 605.9 in the control group. Complete and en bloc dissections were achieved in all cases. One deep muscular injury occurred in the control group (gastric body).

CONCLUSION

The ANUBIS grasper is a user-friendly, effective, and safe tool to achieve adequate traction and exposure of the ESD plane in the pig model.

Simplified magnetic anchor-guided endoscopic submucosal dissection in dogs (with videos)

BACKGROUND

Magnetic anchor-guided endoscopic submucosal dissection (MAG-ESD) was developed to reduce adverse events such as bleeding and perforation and to facilitate ESD. However, the external electromagnet required miniaturization to make it suitable for daily clinical practice.

OBJECTIVE

To evaluate the feasibility of simplified MAG-ESD using permanent magnets.

DESIGN

Case series.

SETTING

Nagoya University Hospital.

SUBJECTS

Beagle dogs.

INTERVENTIONS

The simplified MAG-ESD was performed on 10 representative areas of the stomachs of beagle dogs. The magnetic anchor consisted of an internal magnet attached to a hemoclip. The external and internal magnets were made from the rare earth neodymium.

MAIN OUTCOME MEASUREMENTS

The feasibility of countertraction with good visualization using simplified MAG-ESD. The rate of perforation, the time required for preparation, and attaching the magnetic anchor were also evaluated.

RESULTS

All lesions were successfully resected without perforation. The magnetic anchor could be controlled easily, and direct visualization was maintained by adequate counter traction. Preparing the magnetic anchor and grasping the mucosal edge using the hemoclip was easy and required a median of only 4 minutes (range, 2-7 minutes).

LIMITATIONS

Animal experiment, low number and lesion size.

CONCLUSIONS

This simplified MAG-ESD is feasible and allowed excellent visualization in the dog stomach. The feasibility of this system should be assessed in humans.

Facilitating endoscopic submucosal dissection: the suture-pulley method significantly improves procedure time and minimizes technical difficulty compared with conventional technique: an ex vivo study (with video)

BACKGROUND

The lack of countertraction in endoscopic submucosal dissection (ESD) results in increased technical demand and procedure time. Although the suture-pulley method for countertraction has been reported, its effectiveness compared with the traditional ESD technique remains unclear.

OBJECTIVE

To objectively analyze efficacy of countertraction using the suture-pulley method for ESD.

DESIGN

Prospective ex vivo animal study.

SETTING

Animal laboratory.

INTERVENTIONS

Twenty simulated gastric lesions were created in porcine stomachs by using a standard circular template 30 mm in diameter. In the control arm (n = 10), ESD was performed by using the standard technique. In the suture-pulley arm (N = 10), a circumferential incision was made, and an endoscopic suturing device was used to place the suture pulley.

MAIN OUTCOME MEASUREMENTS

The primary outcome of this study was total procedure time.

RESULTS

The median total procedure time with the suture-pulley method was significantly shorter than the traditional ESD technique (median, 25% to 75%, interquartile range [IQR]: 531 seconds [474.3-549.3 seconds] vs 845 seconds [656.3-1547.5 seconds], P < .001). The median time (IQR) for suture-pulley placement was 160.5 seconds (150.0-168.8 seconds). Although there was a significantly longer procedure time for proximal versus middle/lower stomach lesions with traditional ESD (median, 1601 seconds; IQR, 1547.5-1708.8 seconds vs median, 663 seconds; IQR, 627.5-681.8 seconds; P = .01), there was no significant difference in procedure time for lesions of various locations when using the suture-pulley method. Compared with traditional ESD, the suture-pulley method was less demanding in all categories evaluated by the NASA Task Load Index.

LIMITATIONS

Ex vivo study.

CONCLUSIONS

The suture-pulley method facilitates direct visualization of the submucosal layer during ESD and significantly reduces procedure time and technical difficulty. In addition, the benefit of the suture-pulley method was seen for both simple and more complicated ESDs.

[Endolifter, a new tool for safe and rapid submucosal endoscopic dissection]

BACKGROUND

The effectiveness of endoscopic submucosal dissection (ESD) is similar to that of surgery in the treatment of early lesions. The technique requires a high level of technical skill. Training on biologic models and the mastering of accessories facilitate ESD.

AIMS

The aim was to evaluate the usefulness of the Endolifter in facilitating tissue exposure during ESD in an in vivo porcine model performed at the experimental surgery laboratory of the School of Medicine at the Universidad de São Paulo in Brazil.

MATERIAL AND METHOD

A study with an experimental design employing an in vivo porcine model was conducted on 5 Yorkshire pigs weighing 20-25kg. ESDs were performed using the Endolifter. Mucosal layer dissection was carried out with a dual knife and IT knife and all the endoscopic procedures were performed by a single expert endoscopist.

RESULTS

A total of 25 ESDs were performed, with a technical success rate of 100%. The mean dissection time was 12.34min (range: 10.40-14.50 min) and the mean lesion size was 2.7cm (range: 2.3-3.2cm). There were no episodes of bleeding or perforations during the procedures.

CONCLUSIONS

The Endolifter enables rapid and effective ESDs to be carried out. It is an applicable and easy-to-use device that can be manipulated by a single operator.

Endoscopic therapy for early gastric cancer: Standard techniques and recent advances in ESD

The technique of endoscopic submucosal dissection (ESD) is now a well-known endoscopic therapy for early gastric cancer. ESD was introduced to resect large specimens of early gastric cancer in a single piece. ESD can provide precision of histologic diagnosis and can also reduce the recurrence rate. However, the drawback of ESD is its technical difficulty, and, consequently, it is associated with a high rate of complications, the need for advanced endoscopic techniques, and a lengthy procedure time. Various advances in the devices and techniques used for ESD have contributed to overcoming these drawbacks.

Double-endoscope endoscopic submucosal dissection for the treatment of early gastric cancer accompanied by an ulcer scar (with video)

BACKGROUND

Endoscopic submucosal dissection (ESD) for early gastric cancer accompanied by an ulcer scar remains challenging. Several counter-traction techniques have been attempted to facilitate ESD, but a standard procedure remains to be established.

OBJECTIVE

To evaluate the efficacy and safety of double-endoscope ESD by using a single light source in patients with early gastric cancer accompanied by an ulcer scar.

DESIGN

Single center, retrospective study.

SETTING

Kitasato University East Hospital.

PATIENTS

A total of 30 early gastric cancers with ulcer scars were treated by double-endoscope ESD in 30 patients from October 2008 through May 2012.

INTERVENTION

Double-endoscope ESD.

MAIN OUTCOME MEASUREMENTS

En bloc resection rate, complete resection rate, treatment time, and adverse events.

RESULTS

The use of two endoscopes for ESD provided a good field of vision and allowed counter-traction to be applied to the lesion, clearly facilitating submucosal dissection. Because only a single light source was used, the working space of the endoscope room was not compromised. Moreover, it was unnecessary to prepare another light source or to coordinate image filing. The en bloc resection rate and complete resection rate were 100% and 90%, respectively, and the median treatment time was 80 minutes. As compared with historical control data obtained before the introduction of double-endoscope ESD, the rate of cutting into the specimen was significantly lower (7% vs 35%; P = .01). No serious adverse events occurred during the procedure. Postoperatively, however, 3 patients (10%) had delayed hemorrhage, and 1 (3.3%) had a delayed perforation.

LIMITATIONS

Single-center, nonrandomized study.

CONCLUSION

Our experience indicates that our procedure for double-endoscope ESD is useful and feasible in patients with early gastric cancer accompanied by an ulcer scar.

Endoluminal surgical triangulation: overcoming challenges of colonic endoscopic submucosal dissections using a novel flexible endoscopic surgical platform: feasibility study in a porcine model

BACKGROUND

Colonic endoscopic submucosal dissection (ESD) is challenging as a result of the limited ability of conventional endoscopic instruments to achieve traction and exposure. The aim of this study was to evaluate the feasibility of colonic ESD in a porcine model using a novel endoscopic surgical platform, the Anubiscope (Karl Storz, Tüttlingen, Germany), equipped with two working channels for surgical instruments with four degrees of freedom offering surgical triangulation.

METHODS

Nine ESDs were performed by a surgeon without any ESD experience in three swine, at 25, 15, and 10 cm above the anal verge with the Anubiscope. Sixteen ESDs were performed by an experienced endoscopist in five swine using conventional endoscopic instruments. Major ESD steps included the following for both groups: scoring the area, submucosal injection of glycerol, precut, and submucosal dissection. Outcomes measured were as follows: dissection time and speed, specimen size, en bloc dissection, and complications.

RESULTS

No perforations occurred in the Anubis group, while there were eight perforations (50 %) in the conventional group (p = 0.02). Complete and en bloc dissections were achieved in all cases in the Anubis group. Mean dissection time for completed cases was statistically significantly shorter in the Anubis group (32.3 ± 16.1 vs. 55.87 ± 7.66 min; p = 0.0019). Mean specimen size was higher in the conventional group (1321 ± 230 vs. 927.77 ± 229.96 mm(2); p = 0.003), but mean dissection speed was similar (35.95 ± 18.93 vs. 23.98 ± 5.02 mm(2)/min in the Anubis and conventional groups, respectively; p = 0.1).

CONCLUSIONS

Colonic ESDs were feasible in pig models with the Anubiscope. This surgical endoscopic platform is promising for endoluminal surgical procedures such as ESD, as it is user-friendly, effective, and safe.

CD44 variant 9 expression in primary early gastric cancer as a predictive marker for recurrence

BACKGROUND

Multiple early gastric cancers (EGCs) may develop in 6-14% of patients even after achieving curative endoscopic submucosal dissection (ESD); however, a useful biomarker for predicting recurrence is not available. The present study investigated whether the expression of CD44 variant 9 (CD44v9), a functional cancer stem cell marker, in the primary gastric cancer tissue represents an indicator of recurrence.

METHODS

Eighty-eight patients who underwent ESD for EGC from 2008 to 2010 were enrolled and monitored for recurrence for 3 years. The expression levels of CD44v9 in the tissue of initial EGCs were evaluated by immunohistochemistry, and the recurrence rate was compared between CD44v9-positive and CD44v9-negative groups. The mucin phenotype and expression of microRNA-21 (miR-21) and programmed cell death protein 4 (PDCD4) were also analysed.

RESULTS

The recurrence rate of EGC was significantly higher in the CD44v9-positive group than in the CD44v9-negative group (hazard ratio (HR), 21.8; 95% confidence interval (CI), 5.71-83.1). However, mucin phenotypes and the expression of miR-21 and PDCD4 did not predict recurrence after ESD. Meanwhile, grade of gastric atrophy was also identified as a significant marker of multiple recurrence (HR, 4.95; 95% CI, 1.30-18.8).

CONCLUSION

CD44 variant 9 expression represents a potential predictive marker for recurrence in EGC.