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

Stereo Visual Servoing Control of a Soft Endoscope for Upper Gastrointestinal Endoscopic Submucosal Dissection

Quickly and accurately completing endoscopic submucosal dissection (ESD) operations within narrow lumens is currently challenging because of the environment's high flexibility, invisible collision, and natural tissue motion. This paper proposes a novel stereo visual servoing control for a dual-segment robotic endoscope (DSRE) for ESD surgery. Departing from conventional monocular-based methods, our DSRE leverages stereoscopic imaging to rapidly extract precise depth data, enabling quicker controller convergence and enhanced surgical accuracy. The system's dual-segment configuration enables agile maneuverability around lesions, while its compliant structure ensures adaptability within the surgical environment. The implemented stereo visual servo controller uses image features for real-time feedback and dynamically updates gain coefficients, facilitating rapid convergence to the target. In visual servoing experiments, the controller demonstrated strong performance across various tasks. Even when subjected to unknown external forces, the controller maintained robust performance in target tracking. The feasibility and effectiveness of the DSRE were further verified through ex vivo experiments. We posit that this novel system holds significant potential for clinical application in ESD surgeries.

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

BACKGROUND AND AIMS

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

A Robotized Soft Endoscope with Stereo Vision for Upper Gastrointestinal Endoscopic Submucosal Dissection (ESD)

This work presents a novel dual-segment flexible robotic endoscope designed to enhance reachability and dexterity during ESD surgery. The proposed system is capable of executing multi-angle cutting operations at a small angle relative to the lesion surface, allowing for efficient en-bloc resection. Additionally, the system incorporates two calibrated RGB cameras and a depth estimation algorithm to provide detailed 3D information of the tumour, which is used to guide the control framework. A stereo visual servoing controller is also implemented to improve path-following performance during surgery. Experiments results indicate that the proposed system improves motion stability and precision. The root means square error (RMSE) of circle path following is 1.1991mm with a maximum of 1.4751mm. Ex-vivo testing demonstrates its significant potential for use in endoscopic surgery.

Endoscopic submucosal dissection training: evaluation of an ex vivo training model with continuous perfusion (ETM-CP) for hands-on teaching and training in China

BACKGROUND

The existing ex vivo models of endoscopic submucosal dissection (ESD) cannot simulate intraoperative hemorrhage well. We aimed to establish an ESD training method by applying an ex vivo training model with continuous perfusion (ETM-CP).

METHODS

Four training sessions were conducted for 25 novices under the guidance of 2 experts. Eventually, 10 novices completed ESD operations on a total of 89 patients after the training. The resection effectiveness, resection speed, complication rate, and novice performance before and after the training were compared. The data regarding the effects of the training and the model were gathered through a questionnaire survey.

RESULTS

In terms of the simulation effect of the model, ETM-CP was evaluated as similar to the live pig in all aspects (P > 0.05). The questionnaire analysis revealed that the ESD theoretical knowledge, skill operation, and self-confidence of novices were improved after the training (P < 0.05). The resection time per unit area had a correlation with the number of training periods (rs = - 0.232). For novice performance, the resection time per unit area was shortened (P < 0.05). There was no difference in patient performance between the novice group and the expert group after the training in terms of en bloc resection, R0 resection, complication rate, endoscopic resection bleeding (ERB) score, muscularis propria injury (MPI) score, and resection time per unit area (P > 0.05).

CONCLUSION

The ETM-CP is effective for ESD training.

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.

Over-the-scope-grasper: A new tool for pancreatic necrosectomy and beyond - first multicenter experience

BACKGROUND

Endoscopic treatment of pancreatic necrosis can be challenging and time-consuming because sticky necrotic debris is sometimes difficult to remove. The over-the-scope-grasper, a new tool that has recently become available for this purpose, might also be useful for other indications. However, clinical data on the efficacy and safety of this new device are lacking.

AIM

To evaluate the technical success and safety of the device in a multicenter setting.

METHODS

The over-the-scope-grasper was used in nine selected endoscopic centers between November 2020 and October 2021 for appropriate indications. Overall, 56 procedures were included in the study. We retrospectively evaluated procedural parameters of all endoscopic interventions using a predefined questionnaire, with special respect to technical success, indications, duration of intervention, type of sedation, and complications. In the case of pancreatic necrosectomy, the access route, stent type, number of necrosis pieces removed, and clinical handling were also recorded.

RESULTS

A total of 56 procedures were performed, with an overall technical success rate of 98%. Most of the procedures were endoscopic pancreatic necrosectomies (33 transgastric, 4 transduodenal). In 70% of the procedures, access to the necrotic cavity was established with a lumen apposing metal stent. The technical success of pancreatic necrosectomy was 97%, with a mean of 8 pieces (range, 2-25 pieces) of necrosis removed in a mean procedure time of 59 min (range, 15-120 min). In addition, the device has been used to remove blood clots (n = 6), to clear insufficiency cavities before endoluminal vacuum therapy (n = 5), and to remove foreign bodies from the upper gastrointestinal tract (n = 8). In these cases, the technical success rate was 100%. No moderate or severe/fatal complications were reported in any of the 56 procedures.

CONCLUSION

These first multicenter data demonstrate that the over-the-scope-grasper is a promising device for endoscopic pancreatic necrosectomy, which is also appropriate for removing foreign bodies and blood clots, or cleaning insufficiency cavities prior to endoluminal vacuum therapy.

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.