Methods that Assist Traction during Endoscopic Submucosal Dissection of Superficial Gastrointestinal Cancers: A Systematic Literature Review

Facilitating endoscopic full-thickness resection for gastric submucosal tumors with a novel snare traction method (with video)

BACKGROUND AND AIM

Endoscopic full-thickness resection (EFTR) is a promising technique in treating gastric submucosal tumors originating from the muscularis propria (SMT-MPs). However, it is challenging without counter-traction.

METHODS

A snare was inserted through the forceps channel to grasp the part of the tumor or the mucosa connected to the tumor. The outer sheath and inner wire of snare in vitro were fixed by a pair of hemostatic forceps. The handle of snare was cut off, and the endoscope was pulled out without affecting the traction state of snare. Snare-assisted EFTR (EFTR-S) was then performed with counter-traction. One hundred and four patients with gastric SMT-MPs who received the procedure of EFTR with or without snare traction method were retrospectively analyzed using univariate and multiple regressions, and covariates were adjusted in the multiple analysis.

RESULTS

Compared with EFTR group (n = 36), EFTR-S group (n = 68) showed a higher operative success rate (95.6% vs 72.2%, P = 0.001), a lower incidence of intraoperative hemorrhage (4.4% vs 16.7%, P = 0.038) and shorter operative time among operative successes (53.6 ± 16.6 min vs 67.7 ± 33.4 min, P < 0.001). Univariate logistic analysis showed that snare traction represented a significant factor, which could improve operative successful rate (odds ratio, 8.3; 95% confidence interval, 2.1 to 32.7; P = 0.002). Postoperative outcomes and adverse events among operative successes were similar between the two groups.

CONCLUSIONS

This novel snare traction method may provide an effective counter-traction and reduce the difficulty of EFTR for gastric SMT-MPs.

The Impact of Traction Methods on Endoscopic Submucosal Dissection Efficacy for Gastric Neoplasia: A Systematic Review and Meta-analysis

BACKGROUND

Endoscopic submucosal dissection (ESD) for gastric neoplasms can be challenging due to limited traction and visualization. The efficacy of traction-assisted endoscopic submucosal dissection (TA-ESD) continues to require additional validation. This study aims to explore the safety and efficiency of TA-ESD for early gastric neoplasms located at varying sites, in comparison with conventional endoscopic submucosal dissection (C-ESD).

METHODS

We conducted a comprehensive literature search using databases up until August 2022. The outcome measures procedure time, en bloc resection rate, complete resection rate, procedure time, and procedure-related adverse event rate. We calculated pooled mean differences (MDs) and odds ratios (ORs) for these outcomes.

RESULTS

The mean procedure time was significantly shorter in the TA-ESD group compared to the C-ESD group (MD - 14.9, 95% CI - 21.78 to - 8.03, I2 = 83%, p < 0.0001). Subgroup analysis revealed that mean procedure times for lesions on the greater curvature and upper/middle of the stomach were significantly shorter in the TA-ESD group - 19.2 min (95% CI - 27.75 to - 10.65, I2 = 12%, p < 0.0001) and - 7.35 min (95% CI - 35.4 to - 1.15, p = 0.04), respectively. The en bloc resection and complete resection rates were comparable between the two groups. The rate of perforation was significantly lower in the TA-ESD group than in the C-ESD group (OR 0.36, 95% CI 0.15-0.85, p = 0.02, I2 = 0%).

CONCLUSIONS

This study demonstrates the potential benefits of TA-ESD over C-ESD in treating patients with early-stage gastric tumors, highlighting its safety and efficacy. The findings indicate a significant reduction in procedure times at challenging stomach sites with TA-ESD in comparison to C-ESD.

[Efficacy of endoscopic submucosal dissection assisted by metal-clip pocket creation traction for colorectal tumors]

OBJECTIVE

To evaluate the clinical efficacy of endoscopic submucosal dissection (ESD) assisted by metal-clip pocketcreation traction for treatment of colorectal tumors.

METHODS

We retrospectively analyzed the clinical data of 244 patients with colorectal tumors undergoing colorectal ESD treatment between January, 2019 and December, 2022, including 169 patients receiving ESD without metal-clip pocket-creation traction (N-ESD group) and 75 with traction-assisted ESD (M-ESD group). Propensity score matching was used to screen the patients using general clinical data as the covariates for matching. Operative time, surgical resection outcome indicators, incidence of adverse events, and histopathological diagnosis indicators were compared between the two groups of patients after matching.

RESULTS

The median operative time was significantly shorter in M-ESD group than in N-ESD group (20.0 [15.0, 30.0] vs 30 [20.0, 45.0] min, P=0.008). No significant difference was found in the en bloc resection rate (100% vs 98.6%), complete resection rate (97.3% vs 96%) and radical resection rate (97.3% vs 96%) between the two groups (P>0.05). The incidence of adverse events was low in both groups and showed no significant difference between them (P>0.05).

CONCLUSION

In patients with colorectal tumors, the use of metal-clip pocket-creation traction can shorten the operative time of ESD although it does not significantly reduce the surgical resection rate or incidence of adverse events.

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.

Error-Correcting Mean-Teacher: Corrections instead of consistency-targets applied to semi-supervised medical image segmentation

Semantic segmentation is an essential task in medical imaging research. Many powerful deep-learning-based approaches can be employed for this problem, but they are dependent on the availability of an expansive labeled dataset. In this work, we augment such supervised segmentation models to be suitable for learning from unlabeled data. Our semi-supervised approach, termed Error-Correcting Mean-Teacher, uses an exponential moving average model like the original Mean Teacher but introduces our new paradigm of error correction. The original segmentation network is augmented to handle this secondary correction task. Both tasks build upon the core feature extraction layers of the model. For the correction task, features detected in the input image are fused with features detected in the predicted segmentation and further processed with task-specific decoder layers. The combination of image and segmentation features allows the model to correct present mistakes in the given input pair. The correction task is trained jointly on the labeled data. On unlabeled data, the exponential moving average of the original network corrects the student's prediction. The combined outputs of the students' prediction with the teachers' correction form the basis for the semi-supervised update. We evaluate our method with the 2017 and 2018 Robotic Scene Segmentation data, the ISIC 2017 and the BraTS 2020 Challenges, a proprietary Endoscopic Submucosal Dissection dataset, Cityscapes, and Pascal VOC 2012. Additionally, we analyze the impact of the individual components and examine the behavior when the amount of labeled data varies, with experiments performed on two distinct segmentation architectures. Our method shows improvements in terms of the mean Intersection over Union over the supervised baseline and competing methods. Code is available at https://github.com/CloneRob/ECMT.

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.

Novel Colorectal Endoscopic Submucosal Dissection With Double-Endoscope and Snare-Based Traction

BACKGROUND

Colorectal endoscopic submucosal dissection is technically demanding, and the traction offered by gravity, cap, or clip-with-line during conventional endoscopic submucosal dissection remains unsatisfactory. Robotic systems are still under development and are expensive. We proposed double-scope endoscopic submucosal dissection with strong and adjustable traction offered by snaring the lesion with additional scope.

OBJECTIVE

This study aimed to test the novel double-scope endoscopic submucosal dissection with snare-based traction.

DESIGN

This was a retrospective study that reviewed double-scope endoscopic submucosal dissection compared with matched conventional endoscopic submucosal dissection, and size, location, morphology, and pathology between groups were compared.

SETTINGS

This study was conducted in a referral endoscopy center in a local hospital.

PATIENTS

This study included patients with colorectal lesions receiving double-scope endoscopic submucosal dissection and matched conventional endoscopic submucosal dissection.

MAIN OUTCOME MEASURES

The pathological completeness, procedure time, and complications were analyzed.

RESULTS

Fifteen double-scope endoscopic submucosal dissection procedures, with 11 lesions located in the proximal colon with a median size of 40 mm, were performed. The median procedure time of double-scope endoscopic submucosal dissection was 32.45 (interquartile range, 16.03-38.20) minutes. The time required for second scope insertion was 2.57 (interquartile range, 0.95-6.75) minutes; for snaring, 3.03 (interquartile range, 2.12-6.62) minutes; and for actual endoscopic submucosal dissection, 28.23 (interquartile range, 7.90-37.00) minutes. All lesions were resected completely. No major complication was encountered. The procedure time was significantly shorter than that of 14 matched conventional endoscopic submucosal dissections (54.61 [interquartile range, 33.11-97.25] min; p = 0.021).

LIMITATIONS

This was a single-center, single-operator, retrospective case-controlled study with limited cases.

CONCLUSIONS

This study confirmed the feasibility of double-scope endoscopic submucosal dissection with snare-based traction to shorten procedure time and to simplify endoscopic submucosal dissection. Additional trials are required.

Multi-loop traction device facilitates gastric endoscopic submucosal dissection: ex vivo pilot study and an inaugural clinical experience

BACKGROUND

Endoscopic submucosal dissection (ESD) is technically difficult and requires considerable training. The authors have developed a multi-loop traction device (MLTD), a new traction device that offers easy attachment and detachment. We aimed to evaluate the utility of MLTD in ESD.

METHODS

This ex vivo pilot study was a prospective, block-randomized, comparative study of a porcine stomach model. Twenty-four lesions were assigned to a group that undertook ESD using the MLTD (M-ESD group) and a group that undertook conventional ESD (C-ESD group) to compare the speed of submucosal dissection. In addition, the data of consecutive 10 patients with eleven gastric lesions was collected using electronic medical records to clarify the inaugural clinical outcomes of gastric ESD using MLTD.

RESULTS

The median (interquartile range) speed of submucosal dissection in the M-ESD and C-ESD groups were 141.5 (60.9-177.6) mm2/min and 35.5 (20.8-52.3) mm2/min, respectively; submucosal dissection was significantly faster in the M-ESD group (p < 0.05). The rate of en bloc resection and R0 resection was 100% in both groups, and there were no perforation in either group. The MLTD attachment time was 2.5 ± 0.9 min and the MLTD extraction time was 1.0 ± 1.1 min. Clinical outcomes of MLTD in gastric ESD were almost the same as those of ex vivo pilot study.

CONCLUSIONS

MLTD increased the speed of submucosal dissection in ESD and was similarly effective when used by expert and trainee endoscopists without perforation. MLTD can potentially ensure a safer and faster ESD.

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

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

Double-endoscope assisted endoscopic submucosal dissection for treating tumors in rectum and distal colon by expert endoscopists: a feasibility study

Background

Colorectal endoscopic submucosal dissection (ESD) is an effective but challenging procedure. To facilitate ESD, several methods that apply traction are available; however, the optimal one remains to be established. The aim of this study was to evaluate the feasibility and safety of the double-endoscope assisted ESD (DEA-ESD) by improving traction to treat complex colorectal lesions.

Methods

Naïve or previously treated lesions in the rectum and sigmoid colon were included. A grasping forceps advanced through a small-caliber endoscope (GIF-XP190N, Olympus Medical Systems, Tokyo, Japan, 5.4 mm outer diameter) was used to apply traction to the mucosal flap. Lesions were deemed complex when they exceeded a total of nine points on the SMSA scoring system (size, morphology, site, and access) and recurrent when they were previously treated with endoscopic mucosal resection (EMR). Outcome measures included procedural success, total procedure time, complications, and recurrence rate at 3-month follow-up.

Results

Nine patients (mean age 62.3 ± 14.5 years) were included; five had rectal and four had tumors in the sigmoid colon. The median SMSA score was 14 (SMSA Level IV—complex polyp), while three patients were pre-treated with EMR. DEA-ESD was technically feasible in all cases. En bloc resection and R0 resection rates were 100%, respectively, with a mean procedure time of 128.4 ± 54.1 min. No immediate or delayed complications occurred.

Conclusions

DEA-ESD is a feasible and safe method for treating complex or recurrent tumors in the rectum and distal colon.

Electronic supplementary material

The online version of this article (10.1007/s10151-020-02308-4) contains supplementary material, which is available to authorized users.