Robot-assisted endoscopic submucosal dissection versus conventional ESD for colorectal lesions: outcomes of a randomized pilot study in endoscopists without prior ESD experience (with video)

Colorectal endoscopic submucosal dissection in the USA: The current state and future perspectives

Endoscopic submucosal dissection (ESD) is a transformative advancement in the endoscopic management of superficial gastrointestinal lesions. Initially conceived for the treatment of early gastric cancer, ESD has demonstrated proficiency in achieving en-bloc resection of superficial gastrointestinal lesions. ESD has experienced widespread acceptance in Japan and East Asia; however, its adoption in the USA remains delayed. This initial hesitancy could be attributed to procedural complexity and training demands; nonetheless, recently, ESD has been gaining popularity in the USA. This is due to the advancements in endoscopic technology, tailored training programs, and cumulative evidence regarding the efficacy and safety of ESDs. This review aimed to deliberate the historical progress, current implementation, and prospective trajectory of ESDs in the USA. With ongoing clinical research, technological integration, and educational efforts, ESD is likely to become the gold standard for managing large gastrointesitinal lesions. This progress marks an imperative step toward less invasive, more precise, and patient-centric approaches regarding advanced therapeutic endoscopy in the USA.

Robotics in interventional endoscopy-evolution and the way forward

The integration of robotics into gastrointestinal (GI) endoscopy represents a transformative advancement and bears the potential to bridge the gap between traditional limitations by offering unprecedented precision and control in diagnostic and therapeutic procedures. This review explores the historical progression, current applications and future potential of robotic platforms in GI endoscopy. Originally designed for surgical applications, robotic systems have expanded their reach into endoscopy, potentially enhancing procedural accuracy and reducing ergonomic strain on practitioners. Natural Orifice Transluminal Endoscopic Surgery (NOTES) emerged as a promising technique, leveraging natural orifices to perform minimally invasive surgeries. Despite its initial potential, several factors, including limitations of the available instrumentations and lack of reliable closure techniques, hindered its widespread adoption and progress. Conventional endoscopic tools often fall short in terms of triangulation, traction and degrees of freedom, necessitating the adoption of robotic interventions. Over recent decades, robotic endoscopy has significantly evolved, focusing on both diagnostic and complex therapeutic procedures such as endoscopic sub-mucosal dissection (ESD) and endoscopic full-thickness resection (EFTR). Various robotic platforms demonstrate enhanced safety and efficiency in GI procedures. As the field progresses, the emphasis on clinical validation, advanced training and the exploration of new applications remains crucial. Continuous innovation in robotic technology and endoscopic techniques promises to overcome existing limitations, further revolutionizing the management of GI diseases and improving patient outcomes.

A Novel Retractable Robotic Device for Colorectal Endoscopic Submucosal Dissection

Background/Aims

: Appropriate tissue tension and clear visibility of the dissection area using traction are essential for effective and safe endoscopic submucosal dissection (ESD). In this study, we developed a retractable robot-assisted traction device and evaluated its performance in colorectal ESD.

Methods

: An experienced endoscopist performed ESD 18 times on an ex vivo porcine colon using the robot and 18 times using the conventional method. The outcome measures were procedure time, dissection speed, procedure-related adverse events, and blind dissection rate.

Results

: Thirty-six colonic lesions were resected from ex vivo porcine colon samples. The total procedure time was significantly shorter in robot-assisted ESD (RESD) than in conventional ESD (CESD) (20.1±4.1 minutes vs 34.3±8.3 minutes, p<0.05). The submucosal dissection speed was significantly faster in the RESD group than in the CESD group (36.8±9.2 mm2/min vs 18.1±4.7 mm2/min, p<0.05). The blind dissection rate was also significantly lower in the RESD group (12.8%±3.4% vs 35.1%±3.9%, p<0.05). In an in vivo porcine feasibility study, the robotic device was attached to a colonoscope and successfully inserted into the proximal colon without damaging the colonic wall, and ESD was successfully performed.

Conclusions

: The dissection speed and safety profile improved significantly with the retractable RESD. Thus, our robotic device has the potential to provide simple, effective, and safe multidirectional traction during colonic ESD.

Ultra-minimally invasive endoscopic techniques and colorectal diseases: Current status and its future

Colorectal diseases are increasing due to altered lifestyle, genetic, and environmental factors. Colonoscopy plays an important role in diagnosis. Advances in colonoscope (ultrathin scope, magnetic scope, capsule) and technological gadgets (Balloon assisted scope, third eye retroscope, NaviAid G-EYE, dye-based chromoendoscopy, virtual chromoendoscopy, narrow band imaging, i-SCAN, etc.) have made colonoscopy more comfortable and efficient. Now in-vivo microscopy can be performed using confocal laser endomicroscopy, optical coherence tomography, spectroscopy, etc. Besides developments in diagnostic colonoscopy, therapeutic colonoscopy has improved to manage lower gastrointestinal tract bleeding, obstruction, perforations, resection polyps, and early colorectal cancers. The introduction of combined endo-laparoscopic surgery and robotic endoscopic surgery has made these interventions feasible. The role of artificial intelligence in the diagnosis and management of colorectal diseases is also increasing day by day. Hence, this article is to review cutting-edge developments in endoscopic principles for the management of colorectal diseases.

Novel miniature transendoscopic telerobotic system for endoscopic submucosal dissection (with videos)

BACKGROUND AND AIMS

The lack of tissue traction and instrument dexterity to allow for adequate visualization and effective dissection were the main issues in performing endoscopic submucosal dissection (ESD). Robot-assisted systems may provide advantages. In this study we developed a novel transendoscopic telerobotic system and evaluated its performance in ESD.

METHODS

A miniature dual-arm robotic endoscopic assistant for minimally invasive surgery (DREAMS) was developed. The DREAMS system contained the current smallest robotic ESD instruments and was compatible with the commercially available dual-channel endoscope. After the system was established, a prospective randomized controlled study was conducted to validate the performance of the DREAMS-assisted ESD in terms of efficacy, safety, and workload by comparing it with the conventional technique.

RESULTS

Two robotic instruments can achieve safe collaboration and provide sufficient visualization and efficient dissection during ESD. Forty ESDs in the stomach and esophagus of 8 pigs were completed by DREAMS-assisted ESD or conventional ESD. Submucosal dissection time was comparable between the 2 techniques, but DREAMS-assisted ESD demonstrated a significantly lower muscular injury rate (15% vs 50%, P = .018) and workload scores (22.30 vs 32.45, P < .001). In the subgroup analysis of esophageal ESD, DREAMS-assisted ESD showed significantly improved submucosal dissection time (6.45 vs 16.37 minutes, P = .002), muscular injury rate (25% vs 87.5%, P = .041), and workload (21.13 vs 40.63, P = .001).

CONCLUSIONS

We developed a novel transendoscopic telerobotic system, named DREAMS. The safety profile and technical feasibility of ESD were significantly improved with the assistance of the DREAMS system, especially in the narrower esophageal lumen.

A novel miniature flexible robotic system for endoscopic mucosal dissection: an animal experimental study

Endoscopic submucosal dissection (ESD) is a standard treatment for early gastrointestinal cancer due to its higher rate of en-bloc resection and lower recurrence rate. However, the technical challenges lead to long learning curve and high risks of adverse events. A gastrointestinal flexible robotic-tool system (GIFTS) was proposed to reduce the difficulty and shorten the learning curve of novices. This is an animal study to evaluate the feasibility of GIFTS in ESD. The GIFTS provides a total of 13 degrees of freedom within 10 mm in diameter and variable stiffness function to achieve endoscopic intervention and submucosal dissection with the cooperation of two flexible robotic instruments. One esophageal and four colorectal ESDs in five porcine models were performed. In all five ESD procedures, the GIFTS was successfully intubated and submucosal dissection was completed without perforation or significant bleeding, and there was no system fault. The mean operative time was 99 min, and the mean size of the specimen was 151 mm2. The fifth experiment showed significantly better results than the first one. In vivo animal experiments confirmed the feasibility of GIFTS in performing ESD. The control of GIFTS is friendly to inexperienced beginners, which will help reduce the technical challenges of ESD and shorten the learning curve of endoscopists.

A variable stiffness manipulator with multifunctional channels for endoscopic submucosal dissection

PURPOSE

Endoscopic submucosal dissection (ESD) has become the main treatment for early esophageal and gastric cancers, but the insufficient stiffness and large diameter of current devices increase the difficulty in operation. To address the above problems, this study proposes a variable stiffness manipulator with multifunctional channels for ESD.

METHODS

The proposed manipulator has a diameter of just 10 mm and highly integrates a CCD camera, two optical fibers, two channels for instruments, and one channel for water and gas. Additionally, a compact wire-driven variable stiffness mechanism is also integrated. The drive system of the manipulator is designed, and the kinematics and workspace are analyzed. The variable stiffness and practical application performance of the robotic system are tested.

RESULTS

The motion tests verify that the manipulator has sufficient workspace and motion accuracy. The variable stiffness tests show that the manipulator achieves 3.55 times of stiffness variation instantly. Further insertion tests and operation test demonstrates that the robotic system is safe and can satisfy the needs in motion, stiffness, channels, image, illumination, and injection.

CONCLUSION

The manipulator proposed in this study highly integrates six functional channels and a variable stiffness mechanism in a 10 mm diameter. After kinematic analysis and testing, the performance and application prospect of the manipulator are verified. The proposed manipulator can promote the stability and accuracy of ESD operation.

Initial multicenter experience using a novel articulating through-the-scope traction device for endoscopic submucosal dissection

Background and study aims A single-operator, articulating, through-the-scope (TTS) traction device was recently developed to facilitate endoscopic submucosal dissection (ESD). Clinical data on the performance of this device are limited. We report an initial multicenter experience with ESD using this articulating TTS traction device. Patients and methods Retrospective analysis on all consecutive patients who underwent ESD using this traction device (T-ESD) at five centers between August 2021 and December 2022. Endpoints included: rates of en-bloc resection, R0 resection, curative resection, and adverse events. Results Thirty-six patients (median age 64.8 years; 47.2% women) underwent ESD (median lesion size 40 mm; interquartile range [IRQ]: 27.5-67.5) for lesions in the esophagus (n=2), stomach (n=8), sigmoid colon (n=6), and rectum (n=20). Submucosal fibrosis was encountered in one-third of the lesions (33.3%). Median ESD time was 104.6 minutes (IQR: 65-122). En-bloc, R0 and curative resection were achieved in 94.4%, 91.6%, and 97.2%, respectively. The single patient with non-curative resection of an invasive rectal adenocarcinoma underwent surgery. There were no cases of delayed bleeding or perforation. There was no recurrence on surveillance endoscopy (n=20) at a median of 6 months (IQR: 3.75-6). Conclusions This initial multicenter experience demonstrates high resection rates and excellent safety profile when performing ESD with this novel articulating TTS device. Dynamic real-time traction may lower the technical difficulty of ESD. Additional studies are needed to assess its cost-effectiveness and compare its usefulness with other traction devices and techniques during ESD.

Flexible robotic endoscopy for treating gastrointestinal neoplasms

Therapeutic flexible endoscopic robotic systems have been developed primarily as a platform for endoscopic submucosal dissection (ESD) in the treatment of early-stage gastrointestinal cancer. Since ESD can only be performed by highly skilled endoscopists, the goal is to lower the technical hurdles to ESD by introducing a robot. In some cases, such robots have already been used clinically, but they are still in the research and development stage. This paper outlined the current status of development, including a system by the author’s group, and discussed future challenges.

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

BACKGROUND AND AIMS

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

METHODS

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

RESULTS

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

CONCLUSION

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

Training in Endoscopic Submucosal Dissection in the United States: The Current Paradigm

Endoscopic submucosal dissection (ESD) training in Japan is pursued through a designated master-apprentice, organ-based stepwise training model. However, applying a similar program to the United States is not a practical strategy due to the significant differences in the training system and disease prevalence. To incorporate the ESD training into the current advanced endoscopy fellowship program, the use of recently developed techniques and technologies to improve the efficiency of ESD is ideal. The ESD training program in the United States should be prevalence-based, with increased involvement of trainees depending on their objectively assessed competency levels.

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

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

Comparison of efficiency and safety between dual-clip and rubber band-assisted ESD and conventional ESD for colonic lateral spreading tumors (LSTs) with different levels of technical difficulty: a retrospective case–control study

Background

Dual-clip and rubber band-assisted endoscopic submucosal dissection (DCRB-ESD) is a useful technique in the management of lateral spreading tumors (LSTs) of the colon and is suggested by researchers compared with conventional ESD (C-ESD). The aim of this retrospective study is to further analyze the efficiency and safety of DCRB-ESD in a setting with varying technical difficulties.

Methods

Patients who underwent endoscopic treatment (DCRB-ESD or C-ESD) due to LSTs between Jan 1st, 2019 and Jan 1st, 2022, were retrospectively collected. Patients were classified into the following two groups: the DCRB-ESD group (n = 46) and the C-ESD group (n = 81). Baselines were compared and propensity score matching (PSM) was employed to manage the heterogeneity. The technical difficulty and outcomes of the two groups were evaluated based on a semiquantitative model (CS-CRESD) previously described.

Results

The baseline characteristics of the two groups were balanced except sex and LST classification before PSM and were corrected after PSM. The median ESD operation time of DCRB-ESD was shorter than that of C-ESD (32 vs 41 and 30 vs 44 before and after PSM respectively, P < 0.05). The operation durations of cases with different CS-CRESD scores were different (P < 0.05). In the subgroup with a score of 0, DCRB-ESD showed no advantage than C-ESD in terms of operation duration before and after PSM. In subgroups with a score of 1–3, DCRB-ESD was faster than C-ESD. In subgroups with a score of 4–5, the between-group operation duration was not significantly different due to the limited number of cases, although the median time of DCRB-ESD was shorter. The R0 resection rates, curative resection, complications, and additional surgery in both groups were not significantly different. No adverse events, such as a clip falling off or rubber band rupturing occurred during this study.

Conclusion

DCRB-ESD was an efficient and safe procedure in the management of colonic LSTs. With DCRB-ESD, the operation duration of difficult cases can be shortened without sacrificing complication risk. However, not all cases would benefit from DCRB-ESD. For easy cases (CS-CRESD score = 0), DCRB-ESD may not be prior to C-ESD by experienced endoscopists. A pre-ESD technical difficulty evaluation was recommended to decide whether to perform DCRB-ESD or not.

Novel single-operator through-the-scope traction device for endoscopic submucosal dissection: Outcomes of a multicenter randomized pilot ex-vivo study in trainees with limited endoscopic submucosal dissection experience (with video)

Objectives

Endoscopic submucosal dissection is a technically demanding procedure. The pilot study aimed to prospectively evaluate the efficacy and safety of a novel single‐operator through‐the‐scope dynamic traction device among trainees with limited endoscopic submucosal dissection (ESD) experience.

Methods

Randomized, controlled, pilot study comparing traction‐assisted ESD (T‐ESD) versus conventional ESD (C‐ESD) in an ex‐vivo porcine stomach model. Trainees were randomized to group 1 (T‐ESD followed by C‐ESD) and group 2 (C‐ESD followed by T‐ESD). Lesions were created on the gravity‐dependent area of the stomachs. The primary outcome was submucosal dissection speed. Secondary outcomes included differences in en‐bloc resection, adverse events, and workload, assessed by the National Aeronautical and Space Administration Task Load Index (NASA‐TLX).

Results

Five trainees performed two T‐ESD and two C‐ESD each, for a total of 20 procedures. Submucosal dissection speed was significantly faster in the T‐ESD group compared to the C‐ESD group (43.32 ± 22.61 vs. 24.19 ± 15.86 mm²/min; p = 0.042). En‐bloc resection was achieved in 60% with T‐ESD and 70% with C‐ESD (p = 1.00). The muscle injury rate was higher in the C‐ESD group (50% vs. 10%; p = 0.21) with 1 perforation reported with C‐ESD and none with T‐ESD. NASA‐TLX physical demand was lower with T‐ESD compared to C‐ESD (4.5 ± 2.17 vs. 6.9 ± 2.50; p = 0.03).

Conclusion

T‐ESD resulted in faster submucosal dissection and less physical demand when compared to C‐ESD, as performed by trainees in an ex‐vivo gravity‐dependent model. Future studies are needed to assess its role in human ESD cases.

Robotics in therapeutic endoscopy (with video)

Since its inception, endoscopy has evolved from a solely diagnostic procedure to an expanding therapeutic field within gastroenterology. The incorporation of robotics in gastroenterology initially addressed shortcomings of flexible endoscopes in natural orifice transluminal endoscopy. Developing therapeutic endoscopic robotic platforms now offer operators improved ergonomics, visualization, dexterity, precision, and control and the possibility of increasing proficiency and standardization of complex endoscopic procedures including endoscopic submucosal dissection, endoscopic full-thickness resection, and endoscopic suturing. The following review discusses the history, potential applications, and tools currently available and in development for robotics in therapeutic endoscopy.

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.

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.

A novel flexible auxiliary single-arm transluminal endoscopic robot facilitates endoscopic submucosal dissection of gastric lesions (with video)

BACKGROUND

Using conventional endoscope to perform endoscopic submucosal dissection (ESD) is difficult because of the one-handed operation and blind dissection caused by gravity. Poor visualization of the submucosal plane causes ESD to be associated with a high risk of bleeding and perforation. This study aimed to develop a novel ESD-assistive robot system and to evaluate its efficacy.

METHODS

A novel flexible auxiliary single-arm transluminal endoscopic robot (FASTER) was developed. A total of 36 artificial lesions in ex vivo porcine stomachs were removed using the FASTER-assisted ESD method (n = 18) and the conventional ESD method (n = 18). Lesions were 2 cm or 4 cm in diameter, located on the anterior and posterior walls of the antrum. Primary outcome measurements were dissection time and dissection speed.

RESULTS

The dissection time in FASTER-assisted ESD was significantly shorter than that in conventional ESD (7 min vs 13 min, p = 0.012), mainly because of the faster dissection speed (148.6 vs 97.0 mm²/min, p = 0.002). The total procedure time in FASTER-assisted ESD was shorter than that in conventional ESD, but the difference was not significant (16 min vs 24 min, p = 0.252). Complete en bloc resection was achieved in all lesions. No perforations were detected. The FASTER exhibited the ability of regrasp, multidirectional traction, and proper tension control during ESD.

CONCLUSION

FASTER significantly increased the dissection speed by providing proper traction and achieving good submucosal vision. This new device is expected to facilitate ESD in clinical practice.

Initial clinical experience with a novel flexible endoscopic robot for transanal surgery

Background

The Flex^® Robotic System (Medrobotics, Raynham, MA, USA) is the first miniaturised flexible endoscopic robot that aims to allow surgical manoeuvres beyond the area currently reached by transanal endoscopic microsurgery. The aim of this study is to evaluate our initial clinical experience with this novel tool.

Methods

We prospectively collected all consecutive cases of local excisions of rectal lesions performed with the Flex^® Robotic System performed at the Department of Surgical Sciences of the University of Turin between October 2018 and December 2019. Indications were benign, or early rectal lesions judged unsuitable for endoscopic removal, within 20 cm of the anal verge. Debriefing meetings after each procedure allowed technology assessment leading to the modification, development, and implementation of tools according to the clinical experience. We analysed the data in terms of the safety and efficacy of treatment.

Results

Between October 2018 and February 2020, 26 patients were treated. We performed a full-thickness excision in 14 patients and a submucosal dissection in 12. The median operating time was 115 min (range 45–360 min). In six patients (23.1%), we converted to standard transanal endoscopic operation (TEO^®) (Karl Storz, Tuttlingen, Germany) to complete the procedure. The 30-day morbidity rate was 11.5% (3/26). Positive resection margins were detected in 4 (15.4%) patients. At a minimum follow-up of 12 months, 2 (7.7%) local recurrences were observed.

Conclusions

This first clinical series demonstrates that the Flex^® Robotic System is a fascinating technology that deserves further development to increase surgical dexterity, thereby overcoming current technical limitations and improving clinical outcomes.

Supplementary Information

The online version contains supplementary material available at 10.1007/s10151-022-02577-1.

Near-focus mode for accurate operation during endoscopic submucosal tunneling procedure

INTRODUCTION

When using the endoscopic submucosal tunnel technique (ESTT), the working space in the submucosal tunnel is limited, and the visual field is obscured during close inspection or hemostasis. We aimed to evaluate the efficacy and safety of near-focus mode technique for accurate operation during the submucosal tunneling endoscopic procedure.

MATERIAL AND METHODS

A retrospective two-center study was designed. A total of 51 patients undergoing ESTT procedures with near-focus mode (n = 29) or traditional mode (n = 22) between February 2016 and May 2019 were included in this study.

RESULTS

When using the near-focus mode during the ESTT procedure, it is convenient to ensure a clear image and accurate operation. Adverse events occurred more frequently in the traditional group than in the near-focus group (45.5% vs 17.2%, p = .036). The near-focus group exhibited a lower rate of bleeding compared to the traditional group (0 vs 18.2%, p = .029). Furthermore, the mean hospital stay after the procedure was shorter in the near-focus group than in the traditional group (5.7 days vs 6.7 days, p = .013).

CONCLUSIONS

The visual field is more clearly exposed during submucosal tunneling when using the near-focus mode than when using traditional procedures. This technique appears to be more efficient and secure than the traditional ESTT procedure.

Endoscopic submucosal dissection: How to be more efficient?

Endoscopic submucosal dissection (ESD) allows an "en bloc" resection with safety margins (R0 resection) regardless of the size of the lesion. However, while R0 brings a real benefit for the patient, it is not considered sufficient by many experts to justify the technical difficulties and the longer procedure time compared to piecemeal mucosectomy. The aims of this review are to provide several technical and strategical tips to help you save time and become comfortable during ESD procedures. ESD is divided into several intertwined phases: injection, incision, access to the submucosae, and submucosal dissection itself. During injection there are some mistakes that should not be made: a superficial injection, or on the contrary, a too deep injection. A good needle and good injection technique are mandatory. Some techniques, such as repeated injection or prolonged lifting solution, can help maintain the lift. After this step, mucosal incision can be made, taking care to have a good margin to allow an R0 resection. Starting the mucosal incision from a small point allows calibration of the depth of the incision and then obtaining a nice incision. Trimming is also very important to widen submucosal access. Then comes the submucosal dissection itself. Strategies such as the tunnel strategy or the pocket creation method can help to facilitate dissection, but more importantly, traction systems have become unavoidable, especially in the stomach and colon. Most common complications are bleeding and perforation, and they usually can be managed endoscopically.

Evolving management of colorectal polyps

Advances in endoscopic technology have led to increased success in colorectal cancer (CRC) screening and polyp management, with reduction of CRC incidence and mortality. Despite these advances, CRC is still one of the leading causes of cancer deaths, and half of all CRC develops from lesions that were missed during colonoscopy while one-fifth of CRC arise from prior incomplete resection. Techniques to improve polyp detection are needed, along with optimization of complete resection of any abnormal lesions that are found. This article will review the currently available endoscopic resection techniques and will discuss where they fit in the management of polyps of different sizes and types, such as pedunculated versus nonpedunculated, and those with or without suspected invasion.

Hybrid endoscopic submucosal dissection (ESD) compared with conventional ESD for colorectal lesions: a systematic review and meta-analysis

BACKGROUND

Hybrid endoscopic submucosal dissection (ESD) is increasingly utilized to overcome the complexity of conventional ESD. This systematic review and meta-analysis evaluated the efficacy and safety of hybrid ESD for treatment of colorectal lesions.

METHODS

Search strategies were developed in accordance with PRISMA guidelines. Pooled proportions were calculated with rates estimated using random effects models. Measured outcomes included en bloc resection, procedure-associated complications, recurrence, and need for surgery. Subgroup analyses were performed to compare effectiveness of conventional versus hybrid ESD.

RESULTS

16 studies (751 patients) were included with a mean (standard deviation [SD]) lesion size of 27.96 (10.55) mm. En bloc resection rate was 81.63 % (95 % confidence interval [CI] 72.07 - 88.44; I2  = 80.89). Complications, recurrences, and need for surgery occurred in 7.74 % (95 %CI 4.78 - 12.31; I2  = 65.84), 4.52 % (95 %CI 1.40 - 13.65; I2  = 76.81), and 3.64 % (95 %CI 1.76 - 7.37; I2  = 15.52), respectively. Mean procedure duration was 48.83 (22.37) minutes. On subgroup analyses comparing outcomes for conventional (n = 1703) versus hybrid ESD (n = 497), procedure duration was significantly shorter for hybrid ESD (mean difference 18.45 minutes; P = 0.003), with lower complication rates (P = 0.04); however, hybrid ESD had lower en bloc resection rates (P < 0.001). There was no difference in rates of recurrence or surgery (P > 0.05).

CONCLUSION

While hybrid ESD was safe and effective for removal of colorectal lesions, with shorter procedure duration, fewer complications, and no difference in recurrence versus conventional ESD, hybrid ESD was associated with a lower en bloc resection rate.

Use of an endoscopic flexible grasper as a traction tool for excision of polyps: preclinical trial

Endoscopic submucosal dissection (ESD) is challenging in the right colon. Traction devices can make it technically easier. In this study, we evaluated a flexible grasper with articulating tip and elbow-like bending (IgE) through a double-balloon surgical platform (DESP), compared with an earlier generation grasper without elbow-like bending (Ig). The reach of Ig/IgE was investigated at eight locations using a synthetic colon within a 3D model. Using a fresh porcine colorectum, 4 cm pseudo-polyps were created at the posterior wall of the ascending colon. Fifty-four ESD procedures were performed using three techniques: standard ESD (STD), ESD using Ig (DESP + Ig), and ESD using IgE (DESP + IgE). IgE was able to reach the full circumference at all the locations, whereas the medial walls proximal to the descending colon were out of Ig’s reach. Compared with the STD, both DESP + Ig and DESP + IgE showed significantly shorter procedure time (STD vs. DESP + Ig vs. DESP + IgE = median 48.9 min vs. 38.6 vs. 29.9) and fewer injuries (1.5 vs. 0 vs. 0). Moreover, the DESP + IgE had a shorter procedure time than the DESP + Ig (p = 0.0025). The IgE with DESP increased instrument reach compared to Ig, and likely represented a traction tool for excision of large pseudo-polyps in the right colon.

Colonic endoscopic submucosal dissection using a novel robotic system (with video)

BACKGROUND AND AIMS

One of the difficulties in performing endoscopic submucosal dissection (ESD) is the lack of retraction during submucosal dissection. The development of the EndoMaster EASE System (EndoMaster Pte Ltd, Singapore) aims to enhance the safety and efficacy of ESD through 2 flexible robotic arms for tissue retraction and dissection. This is a preclinical animal study to evaluate the performance of colorectal ESD using the latest version of the EndoMaster EASE System.

METHODS

The latest version of the EndoMaster EASE System consists of an independently designed, flexible platform with a built-in endoscopic imaging system and 3 working channels, 2 for the passage of robotic arms and 1 for accessories. In this animal study, the outcome measures were operating time (from starting incision to finishing dissection), completeness of resection, procedure-related adverse events, and limitations of arm manipulation in a narrow working space as assessed by counting the frequency of blind cutting.

RESULTS

Five ESD procedures were performed in a 66.7-kg porcine model with the animal under general anesthesia. The mean operative time was 73.8 minutes, and the mean size of the specimen resected was 1340 mm². There was no perforation, although profuse bleeding was encountered during 1 robotic ESD procedure.

CONCLUSIONS

The current preclinical study confirmed the feasibility of performing colorectal ESD using the latest version of the EndoMaster EASE System. The system was also tested for the ability to manage adverse events including bleeding and perforation. This study provided important preclinical experience for clinical trial.

Non-Technical Skill Assessment and Mental Load Evaluation in Robot-Assisted Minimally Invasive Surgery

BACKGROUND: Sensor technologies and data collection practices are changing and improving quality metrics across various domains. Surgical skill assessment in Robot-Assisted Minimally Invasive Surgery (RAMIS) is essential for training and quality assurance. The mental workload on the surgeon (such as time criticality, task complexity, distractions) and non-technical surgical skills (including situational awareness, decision making, stress resilience, communication, leadership) may directly influence the clinical outcome of the surgery. METHODS: A literature search in PubMed, Scopus and PsycNet databases was conducted for relevant scientific publications. The standard PRISMA method was followed to filter the search results, including non-technical skill assessment and mental/cognitive load and workload estimation in RAMIS. Publications related to traditional manual Minimally Invasive Surgery were excluded, and also the usability studies on the surgical tools were not assessed. RESULTS: 50 relevant publications were identified for non-technical skill assessment and mental load and workload estimation in the domain of RAMIS. The identified assessment techniques ranged from self-rating questionnaires and expert ratings to autonomous techniques, citing their most important benefits and disadvantages. CONCLUSIONS: Despite the systematic research, only a limited number of articles was found, indicating that non-technical skill and mental load assessment in RAMIS is not a well-studied area. Workload assessment and soft skill measurement do not constitute part of the regular clinical training and practice yet. Meanwhile, the importance of the research domain is clear based on the publicly available surgical error statistics. Questionnaires and expert-rating techniques are widely employed in traditional surgical skill assessment; nevertheless, recent technological development in sensors and Internet of Things-type devices show that skill assessment approaches in RAMIS can be much more profound employing automated solutions. Measurements and especially big data type analysis may introduce more objectivity and transparency to this critical domain as well. SIGNIFICANCE: Non-technical skill assessment and mental load evaluation in Robot-Assisted Minimally Invasive Surgery is not a well-studied area yet; while the importance of this domain from the clinical outcome's point of view is clearly indicated by the available surgical error statistics.

Clinical adoption of robotics in endoscopy: Challenges and solutions

The endoscope was traditionally used as a diagnostic instrument. In past decades, it has increasingly been adapted for therapeutic intents. Subsequently, the master–slave robotic concept was introduced into the field of endoscopy to potentially reduce the difficulty and complication rates of endoscopic therapeutic procedures. As interest in robotic endoscopy intensified, progressively more robotic endoscopic platforms were developed, tested, and introduced. Nevertheless, the future of robotic endoscopy hinges on the ability to meet specific clinical needs of procedurists. Three aspects are vital in ensuring continued success and clinical adoption of the robotic endoscope—demonstration of clinical safety and cost‐efficacy of the device, widespread availability of directed training opportunities to enhance technical skills and clinical decision‐making capabilities of the procedurist, and continued identification of new clinical applications beyond the current uses of the device. This review provides a brief discussion of the historical development of robotic endoscopy, current robotic endoscopic platforms, use of robotic endoscopy in conventional therapeutic endoscopic procedures, and the future of robotic endoscopy.

Robotic endoscopic submucosal dissection and full-thickness excision for laterally spreading tumors of the rectum

Endoscopic submucosal dissection (ESD) is technically demanding and time-consuming. Moreover, it bears a high risk of adverse events compared to other endoscopic methods, due to the lack of tissue manipulation. Robotic technology can significantly reduce the time of the procedure and increase the rate of complete resection for ESD. In the case of an unclear deep margin it allows to proceed to the full-thickness excision of the bowel wall. While the gain over transanal endoscopic microsurgery (TEM) is limited today, the longer systems currently under development will allow these complex procedures to be performed at least in the left side of the colon. The Supplementary video shows the application of the Flex Robotic System to perform an ESD and a full-thickness excision.

Robotics in flexible endoscopy: current status and future prospects

PURPOSE OF REVIEW

Advanced endoscopy procedures are technically challenging and require extensive training. Recent technological advances made in computer science and robotics have the potential to enhance the performance of complex intraluminal and transluminal interventions and potentially optimize precision and safety. This review covers the different technologies used for robot-assisted interventions in the gastrointestinal tract, organized according to their clinical availability, and focusing on flexible endoscopy-based systems.

RECENT FINDINGS

In the curvilinear gastrointestinal anatomy, robotic technology can enhance flexible endoscopes to augment effectiveness, safety, and therapeutic capabilities, particularly for complex intraluminal and transluminal interventions. Increased visual angles, increased degrees of freedom of instrumentation, optimized navigation, and locomotion, which may lead to a reduced physician learning curve and workload, are promising achievements with the promise to ultimately replace conventional endoscopy techniques for screening and therapeutic endoscopy.

SUMMARY

The majority of these devices are not commercially available yet. The best clinical applications are also currently being researched. Nonetheless, robotic assistance may encourage surgeons to use flexible endoscopes to administer surgical therapies and increase interest among gastroenterologists in advanced therapies. Robotics may be a means to overcome the technical obstacles of incisionless natural orifice procedures and favor an increased adoption of complex endoscopic procedures such as third-space therapies.

The evolution of lower gastrointestinal endoscopy: where are we now?

Lower gastrointestinal endoscopy has evolved over time, fulfilling a widening diagnostic and therapeutic remit. As our understanding of colorectal cancer and its prevention has improved, endoscopy has progressed with improved diagnostic technologies and advancing endoscopic therapies. Despite this, the fundamental design of the endoscope has remained similar since its inception. This review presents the important role lower gastrointestinal endoscopy serves in the prevention of colorectal cancer and the desirable characteristics of the endoscope that would enhance this. A brief history of the endoscope is presented. Current and future robotic endoscopic platforms, which may fulfil these desirable characteristics, are discussed. The incorporation of new technologies from allied scientific disciplines will help the endoscope fulfil its maximum potential in preventing the increasing global burden of colorectal cancer. There are a number of endoscopic platforms under development, which show significant promise.

Endoscopic submucosal dissection versus transanal endoscopic surgery for the treatment of early rectal tumor: a systematic review and meta-analysis

BACKGROUND

Minimally invasive treatment of early-stage rectal lesion has presented good results, with lower morbidity than surgical resection. Transanal endoscopic microsurgery (TEM) and transanal minimally invasive surgery (TAMIS) are the main methods of transanal surgery. However, endoscopic submucosal dissection (ESD) has been gaining ground because it allows en bloc resections with low recurrence rates. The aim of this study was to analyze ESD in comparison with transanal endoscopic surgery.

METHODS

We searched MEDLINE, EMBASE, SciELO, Cochrane CENTRAL, and Lilacs/Bireme with no restrictions on the date or language of publication. The outcomes evaluated were recurrence rate, complete (R0) resection rate, en bloc resection rate, length of hospital stay, duration of the procedure, and complication rate.

RESULTS

Six retrospective cohort studies involving a collective total of 326 patients-191 in the ESD group and 135 in the transanal endoscopic surgery group were conducted. There were no statistically significant differences between the groups for any of the outcomes evaluated.

CONCLUSIONS

For the minimally invasive treatment of early rectal tumor, ESD and surgical techniques do not differ in terms of local recurrence, en bloc resection rate, R0 resection rate, duration of the procedure, length of hospital stay, or complication rate, however, evidence is very low.