Endoscopic submucosal dissection of gastric lesions by using a Master and Slave Transluminal Endoscopic Robot (MASTER)

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.

Efficacy, safety, and advantages of magnetic anchor-guided endoscopic submucosal dissection vs conventional endoscopic submucosal dissection: A retrospective paired cohort study

BACKGROUND

Endoscopic submucosal dissection (ESD) has been recommended as the first-line treatment for early gastric cancer (EGC). However, poor visualization of the operative field increases both the procedure time and the risk of complications, especially for large and difficult lesions. We introduced a novel technique, magnetic anchor-guided ESD (MAG-ESD) and compared it with conventional ESD (C-ESD) for the treatment of large EGCs in terms of efficacy, safety, and advantages.

METHODS

Patients with large EGCs who underwent MAG-ESD or C-ESD at the First Affiliated Hospital of Xi'an Jiaotong University from March 2020 to March 2022 were retrospectively enrolled in this study. The patients in the MAG-ESD cohort were matched to those in the C-ESD cohort using propensity score-based matching. The operation time, submucosal dissection time, complete resection status, magnetic anchor, adverse event rate, and tumor recurrence rate were evaluated.

RESULTS

Twenty-two patients who underwent MAG-ESD were ultimately matched to those who underwent C-ESD. The median operation time of MAG-ESD and C-ESD was 43 minutes (IQR, 35.2-49.5) and 50.5 minutes (IQR, 42.0-76.0), respectively, among which the submucosal dissection time was 7.6 minutes (IQR, 5.2-10.4) and 14.8 minutes (IQR, 10.8-19.6), respectively. The operation time of MAG-ESD was shorter than that of C-ESD, especially the submucosal dissection time (P < .05). There was a lower incidence of adverse events associated with MAG-ESD (P < .05) when magnetic anchors were successfully placed and retrieved.

CONCLUSION

MAG-ESD is feasible, effective, safe, and simple for the treatment of large EGCs at different sites and has a high anchor success rate, which could shorten the operation time and reduce the adverse event rate.

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.

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.

Magnetic anchor technique assisted endoscopic submucosal dissection for early esophageal cancer

BACKGROUND

Esophageal cancer has high incidence globally and is often diagnosed at an advanced stage. With the widespread application of endoscopic technologies, the need for early detection and diagnosis of esophageal cancer has gradually been realized. Endoscopic submucosal dissection (ESD) has become the standard of care for managing early tumors of the esophagus, stomach, and colon. However, due to the steep learning curve, difficult operation, and technically demanding nature of the procedure, ESD has currently been committed to the development of various assistive technologies.

AIM

To explore the feasibility and applicability of magnetic anchor technique (MAT)-assisted ESD for early esophageal cancer.

METHODS

Isolated pig esophagi were used as the experimental model, and the magnetic anchor device was designed by us. The esophagi used were divided into two groups, namely the operational and control groups, and 10 endoscopists completed the procedure. The two groups were evaluated for the following aspects: The total operative time, perforation rate, rate of whole mucosal resection, diameter of the peering mucosa, and scores of endoscopists' feelings with the procedure, including the convenience, mucosal surface exposure degree, and tissue tension. In addition, in the operational group, the soft tissue clip and the target magnet (TM) were connected by a thin wire through a small hole at the tail end of the TM. Under gastroscopic guidance, the soft tissue clip was clamped to the edge of the lesioned mucosa, which was marked in advance. By changing the position of the anchor magnet (AM) outside the esophagus, the pulling force and pulling direction of the TM could be changed, thus exposing the mucosal peeling surface and assisting the ESD.

RESULTS

Herein, each of the two groups comprised 10 isolated esophageal putative mucosal lesions. The diameter of the peering mucosa did not significantly differ between the two groups (2.13 ± 0.06 vs 2.15 ± 0.06, P = 0.882). The total operative time was shorter in the operational group than in the control group (17.04 ± 0.22 min vs 21.94 ± 0.23 min, P < 0.001). During the entire experiment, the TM remained firmly connected with the soft tissue clip and did not affect the opening, closing, and release of the soft tissue clip. The interaction between the TM and AM could provide sufficient tissue tension and completely expose the mucosa, which greatly assists the surgeon with the operation. There was no avulsion of the mucosa, and mucosal lesions were intact when peeled. Therefore, the scores of endoscopists' feelings were higher in the operational group than in the control group in terms of the convenience (9.22 ± 0.19 vs 8.34 ± 0.15, P = 0.002), mucosal surface exposure degree (9.11 ± 0.15 vs 8.25 ± 0.12, P < 0.001), and tissue tension (9.35 ± 0.13 vs 8.02 ± 0.17, P < 0.001). The two groups did not significantly differ in the perforation rate and rate of whole mucosal resection.

CONCLUSION

We found MAT-assisted ESD safe and feasible for early esophageal cancer. It could greatly improve the endoscopic operation experience and showed good clinical application prospects.

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.

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.

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.

Progress in Control-Actuation Robotic System for Gastrointestinal NOTES Development

Purpose

Natural orifice transluminal endoscopic surgery (NOTES) is a minimally invasive surgical procedure that reduces patient trauma, infection probability, and rehabilitation time. This paper reviews the progress made in the control-actuation robotic systems for gastrointestinal NOTES development. Material and Methods. A survey on both existing and state-of-the-art control-actuation robotic systems for gastrointestinal NOTES was conducted in December 2021.

Results

Nine control-actuation robotic systems for gastrointestinal NOTES were identified. The structures and specifications of these robotic systems were reported. The technical parameters were also discussed. Special attention was directed to systems using a control-actuation structure and tendon-driven mechanism. The control-actuation robotic systems typically deploy a control-actuation structure and tendon-driven mechanism. Control-actuation robotic systems for gastrointestinal NOTES show great ability to improve operational accuracy and flexibility and flatten the learning curve of procedures. These characteristics suggest that the use of control-actuation robotic systems is worth exploring in future development.

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.

Future challenges in gastroenterology and hepatology, between innovations and unmet needs: A SIGE Young Editorial Board's perspective

Gastroenterology, Digestive Endoscopy and Hepatology have faced significant improvements in terms of diagnosis and therapy in the last decades. However, many fields still remain poorly explored, and many questions unanswered. Moreover, basic-science, as well as translational and clinical discoveries, together with technology advancement will determine further steps toward a better, refined care for many gastroenterological disorders in the future. Therefore, the Young Investigators of the Italian Society of Gastroenterology (SIGE) joined together, offering a perspective on major future innovations in some hot clinical topics in Gastroenterology, Endoscopy, and Hepatology, as well as the current pitfalls and the grey zones.

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.

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.

Endoscopic submucosal dissection using a detachable assistant robot: a comparative in vivo feasibility study (with video)

BACKGROUND

Appropriate tissue tension and clear visibility of the dissection area using traction are essential for effective and safe endoscopic submucosal dissection (ESD). We developed a robotic assistive traction device for flexible endoscopy and compared its safety and efficiency in ESD between experienced and novice endoscopists.

METHODS

Robotic ESD was performed by experienced and novice endoscopist groups (n = 2, each). The outcomes included time to complete each ESD step, total procedure time, size of the dissected mucosa, rate of en bloc resection, and major adverse events. Furthermore, incision and dissection speeds were compared between groups.

RESULTS

Sixteen gastric lesions were resected from nine live pigs. The submucosal incision speed was significantly faster in the expert group than in the novice group (P = 0.002). There was no significant difference in the submucosal dissection speed between the groups (P = 0.365). No complications were reported in either group.

CONCLUSIONS

When the robot was assisting in the ESD procedure, the dissection speed improved significantly, especially in the novice surgeons. Our robotic device can provide simple, effective, and safe multidirectional traction during ESD.

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.

Robot-Assisted Endoscopic Resection: Current Status and Future Directions

Therapeutic endoscopic resection has gained favor for its ability to achieve high en bloc and histologically complete resection rates via a minimally invasive approach. The main technical difficulties faced by interventionists are first the lack of traction causing suboptimal visualization of the dissection field and second, the lack of triangulation using existing therapeutic apparatuses. These challenges can be overcome with the use of robots and the multiple degrees of freedom afforded by the robotic wrists. Nevertheless, complications such as bleeding and perforation can occur. It is hence beneficial for the robotic device to be equipped with additional abilities such as suturing. Once the robotic prototypes have been fully optimized and marketed, a structured program should be instituted to ensure proper and adequate training of the end-users. The future of robotics should then explore the possibility of developing a soft robot or a robot with more natural human-like movements. A robot with a force feedback mechanism would be superior and improve safety. Eventually, a supervised autonomous robot may perform interventions with greater precision and accuracy than an expert procedurist. This review describes the benefits of robot-assisted endoscopic resections, recent developments aimed at managing iatrogenic complications and future directions for robotic endoscopy.

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 endoscopy. A review of the literature

Purpose

To present new endoscopic robotic devices in the context of minimally invasive procedures with high precision and automation.

Methods

Review of the literature by December 2018 on robotic endoscopy.

Results

We present the studies and investments for robotic implementation and flexible endoscopy evolution. We divided them into forceps manipulation platforms, active endoscopy and endoscopic capsule. They try to improve forceps handling and stability and to promote active movement.

Conclusion

The implementation and propagation of robotic models depend on doing what the endoscopist is unable to. The new devices are moving forward in this direction.

Development of a Novel Gastrointestinal Endoscopic Robot Enabling Complete Remote Control of All Operations: Endoscopic Therapeutic Robot System (ETRS)

Background and Objective

The master and slave transluminal endoscopic robot and other flexible endoscopy platforms are designed primarily for the remote control of forceps, with manipulation of the endoscope itself still dependent on conventional techniques. We have developed an endoscopic therapeutic robot system (ETRS) that provides complete remote control of all forceps and endoscope operations.

Method

We carried out endoscopic submucosal dissection (ESD) in porcine stomachs using the ETRS. All procedures were completed with the endoscopist seated at the console the entire time.

Results

Total en bloc resection was achieved in all 7 cases with no complications. The mean total procedure time was 36.14 ± 14.98 min, the mean size of the resected specimen was 3.39 ± 0.66 cm × 3.03 ± 0.63 cm, and the mean dissection time was 14.91 ± 8.61 min.

Conclusion

We successfully used the ETRS to perform completely remote-controlled ESD in porcine stomachs.

Endoscopic robotic suturing: The way forward

Traditionally, suturing is performed in open surgery using a needle holder and forceps. The aim is to achieve accurate approximation of both edges of the wound and to tie a secure knot. With the development of laparoscopic surgery, traditional suturing methods have been adapted to meet the constraints of rigid laparoscopic instruments with limited degrees of freedom. The subsequent introduction of three-dimensional robotic suturing has since made intracorporeal suturing easier to learn, primarily because of its intuitiveness and the additional degree of freedom of the robotic wrists. With the increasing popularity of therapeutic endoscopic procedures for early gastrointestinal cancers, devices allowing for endoscopic suturing have since been developed. Nevertheless, these devices remain challenging to use as they require double-channel endoscopes and do not have the extra degree of freedom of robotic wrists. The introduction of robotics to the field of endoscopic suturing has proven to be promising. This review describes the development and adaptation of basic suturing techniques to various platforms, such as laparoscopic, robotic and endoscopic.

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.

Endoscopy robotics: Current and future applications

Many different types of endoscopy robot have been developed or are under development. Some of these innovative biotechnologies are dedicated to complex endoscopic procedures such as endoscopic submucosal dissection whereas others are purely diagnostic. In endoscopy robotics, there are still several problems that need a solution. These problems basically concern robotic locomotion and instrument control, as well as clinical application. In most cases, the technology is still under development. The current fields of investigation are augmented reality, advances in actuation and reduction of hysteresis, optical analysis, wireless movement transmission and many others. Besides endoscopic submucosal dissection, other promising fields of implementation of endoscopy robots are natural orifices transluminal endoscopic surgery and bariatric endoscopy. Obviously, endoscopy robots are expensive, but both doctors and health system providers are becoming more aware of the possibilities that these platforms can offer. Improvement of the performance of endoscopy robots undoubtedly will lead to their widespread use and, therefore, a balance in cost-effectiveness.

Haptic feedback is useful in remote manipulation of flexible endoscopes

Background and study aims  We developed the Endoscopic Operation Robot (EOR) version 3, offering built-in haptic feedback and manipulation of the entire scope with one hand. Manipulation of the flexible endoscope is done entirely remotely. However, inclusion of haptic feedback places a huge burden on the system. Our purpose in this study was to determine whether haptic feedback is needed in remote manipulation of a flexible endoscope. Methods  Five endoscopists performed total colonoscopy using a colonoscopy training model. A trial was conducted in which the endoscope was inserted up to the cecum five times with haptic feedback and five times without haptic feedback. Insertion time, maximum and mean haptic force, and incidence of sigmoid colon overstretching were compared between groups. Results  Insertion time was significantly shorter with haptic feedback than without, and overstretching of the sigmoid colon was less frequent. Insertion could thus be performed without using excessive force. Conclusion  Haptic feedback is useful for remote control manipulation of flexible endoscopes.

Robotics for Advanced Therapeutic Colonoscopy

Although colonoscopy was originally a diagnostic imaging procedure, it has now expanded to include an increasing range of therapeutic interventions. These procedures require precise maneuvers of instruments, execution of force, efficient transmission of force from the operator to the point of application, and sufficient dexterity in the mobilization of endoscopic surgical instruments. The conventional endoscope is not designed to support technically demanding endoscopic procedures. In case of colonoscopy, the tortuous anatomy of the colon makes inserting, moving, and orientating the endoscope difficult. Exerting excessive pressure can cause looping of the endoscope, pain to the patient, and even perforation of the colon. To mitigate the technical constraints, numerous technically enhanced systems have been developed to enable better control of instruments and precise delivery of force in the execution of surgical tasks such as apposing, grasping, traction, counter-traction, and cutting of tissues. Among the recent developments are highly dexterous robotic master and slave systems, computer-assisted or robotically enhanced conventional endoscopes, and autonomously driven locomotion devices that can effortlessly traverse the colon. Developments in endoscopic instrumentations have overcome technical barriers and opened new horizons for further advancements in therapeutic interventions. This review describes examples of some of these systems in the context of their applications to advanced therapeutic colonoscopy.

Global Evaluative Assessment of Robotic Skills in Endoscopy (GEARS-E): objective assessment tool for master and slave transluminal endoscopic robot

BACKGROUND AND STUDY AIMS

 The Master and Slave Transluminal Endoscopic Robot (MASTER) is a novel robotic endosurgical system with two operating arms that offer multiple degrees of freedom. We developed a new assessment tool, the Global Evaluative Assessment of Robotic Skills in Endoscopy (GEARS-E), derived from existing tools in laparoscopic and robotic surgery, and evaluated its utility in the performance of procedures using MASTER.

METHODS

This was a pilot study conducted in vivo and ex vivo on animals. Three operators (Novice-1, Novice-2 and Expert) performed a total of five endoscopic submucosal dissections (ESD) using MASTER. Novice operators had no MASTER experience and the expert had previously performed eight MASTER ESDs. Operator performance was assessed by four independent evaluators using GEARS-E, which has a maximum score of 25 for five domains representing various skill-related variables (depth perception, bimanual dexterity, efficiency, tissue handling and autonomy).

RESULTS

The mean global rating scores for Novice-1 first attempt, Novice-1 second attempt, Novice-2 first attempt, Novice-2 second attempt and Expert's cases were 13.0, 16.0, 13.3, 15.5, and 21.5, respectively. The mean scores of each of the five domains were statistically higher for the second attempts compared to the first attempts for both Novice-1 and Novice-2. The mean scores of each of the five domains for the Expert's case were consistently higher than those for the two novice operators in both their first and second attempts.

CONCLUSION

Results using GEARS-E showed correlations between surgical experience and MASTER ESD. As an assessment tool for evaluation of surgical skills, GEARS-E has great potential for application in MASTER procedures.

Use of the EndoMaster robot-assisted surgical system in transoral robotic surgery: A cadaveric study

BACKGROUND

The EndoMaster is a novel robot-assisted surgical system originally designed for endoscopic resection of gastrointestinal polyps and tumours. It incorporates two robotic arms (a grasper and a probe for monopolar diathermy) into the end of a flexible endoscope, creating improved manoeuvrability, with two arms allowing for 9 degrees of movement and triangulation; this enables fine manipulation and dissection of tissues.

METHODS

The EndoMaster was used in two human cadavers to perform 4 radical tonsillectomies to evaluate its performance in transoral robotic surgery (TORS).

RESULTS

The EndoMaster allowed for good visualization of the surgical field and its compact form factor allowed for quick docking and avoided the problem of clashing of the working arms.

CONCLUSION

The EndoMaster system shows promising potential for use in TORS. Further refinements to movements of the effector arms are required.

A new robotic-assisted flexible endoscope with single-hand control: endoscopic submucosal dissection in the ex vivo porcine stomach

BACKGROUND

Difficulties in endoscopic operations and therapeutic procedures seem to occur due to the complexity of operating the endoscope dial as well as difficulty in performing synchronized movements with both hands. We developed a prototype robotic-assisted flexible endoscope that can be controlled with a single hand in order to simplify the operation of the endoscope. The aim of this study was to confirm the operability of the robotic-assisted flexible endoscope (RAFE) by performing endoscopic submucosal dissection (ESD).

METHODS

Study 1: ESD was performed manually or with RAFE by an expert endoscopist in ex vivo porcine stomachs; six operations manually and six were performed with RAFE. The procedure time per unit circumferential length/area was calculated, and the results were statistically analyzed. Study 2: We evaluated how smoothly a non-endoscopist can move a RAFE compared to a manual endoscope by assessing the designated movement of the endoscope.

RESULTS

Study 1: En bloc resection was achieved by ESD using the RAFE. The procedure time was gradually shortened with increasing experience, and the procedure time of ESD performed with the RAFE was not significantly different from that of ESD performed with a manual endoscope. Study 2: The time for the designated movement of the endoscope was significantly shorter with a RAFE than that with a manual endoscope as for a non-endoscopist.

CONCLUSIONS

The RAFE that we developed enabled an expert endoscopist to perform the ESD procedure without any problems and allowed a non-endoscopist to control the endoscope more easily and quickly than a manual endoscope. The RAFE is expected to undergo further development.

Flexible robotic endoscopy: current and original devices

Two current major research topics concern the incorporation of flexible robotic endoscopy systems developed for natural-orifice translumenal endoscopic surgery (NOTES), primarily for the purpose of remote forceps operation, into endoscopic submucosal dissection (ESD) and other flexible endoscopic treatments and the use of robots for the manipulation of flexible endoscopes themselves with the aim of enabling the remote insertion of colonoscopes, etc. However, there are still many challenges that remain to be addressed; the ideal robotic endoscope has not yet been realized. This article reviews the ongoing developments and our own efforts in the area of flexible robotic endoscopy.

Management of early colonic neoplasia: where are we now and where are we heading?

There have been considerable advances in the endoscopic treatment of colorectal neoplasia. The development of endoscopic submucosal dissection and full thickness resection techniques is changing the way benign disease and early cancers are managed. This article reviews the evidence behind these new techniques and discusses where this field is likely to move in the future. Areas covered: A PubMed literature review of resection techniques for colonic neoplasia was performed. The clinical and cost effectiveness of endoscopic mucosal resection (EMR) is examined. The development of endoscopic submucosal dissection (ESD) and knife assisted resection is described and issues around training reviewed. Efficacy is compared to both EMR and transanal endoscopic microsurgery. The future is considered, including full thickness resection techniques and robotic endoscopy. Expert commentary: The perceived barriers to ESD are falling, and views that such techniques are only possible in Japan are disappearing. The key barriers to uptake will be training, and the development of educational programmes should be seen as a priority. The debate between TEMS and ESD will continue, but ESD is more flexible and cheaper. This will become less significant as the number of endoscopists trained in ESD grows and some TEMS surgeons may shift across towards ESD.

Current and emerging robotic assisted intervention for Notes

INTRODUCTION

Natural orifices transluminal endoscopic surgery (notes) procedures are limited by a number of factors including closure of the internal entry point, loss of triangulation, and unstable operative platform. Areas covered: In this paper, new technical developments in different aspects of robotic assisted NOTES interventions are reviewed. We further address new research opportunities for more widespread clinical acceptance of robotic assisted NOTES procedures. Expert commentary: The application of robotics in NOTES intervention is still in its infancy. The development of more compact, smart and intuitive robotic NOTES systems holds much promise for the future of NOTES application.

Recent traction methods for endoscopic submucosal dissection

Endoscopic mucosal resection (EMR) is problematic with regard to en bloc and curable resection rates. Advancements in endoscopic techniques have enabled novel endoscopic approaches such as endoscopic submucosal dissection (ESD), which has overcome some EMR problems, and has become the standard treatment for gastrointestinal tumors. However, ESD is technically difficult. Procedure time is longer and complications such as intraoperative perforation and bleeding occur more frequently than in EMR. Recently various traction methods have been introduced to facilitate ESD procedures, such as clip with line, external forceps, clip and snare, internal traction, double scope, and magnetic anchor. Each method must be used appropriately according to the anatomical characteristics. In this review we discuss recently proposed traction methods for ESD based on the characteristics of various anatomical sites.

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.

Endoscopic surgery - exploring the modalities

The adoption of endoscopic surgery continues to expand in clinical situations with the recent natural orifice transluminal endoscopic surgery technique enabling abdominal organ resection to be performed without necessitating any skin incision. In recent years, the development of numerous devices and platforms have allowed for such procedures to be carried out in a safer and more efficient manner, and in some ways to better simulate triangulation and surgical tasks (e.g., suturing and dissection). Furthermore, new novel techniques such as submucosal tunneling, endoscopic full-thickness resection and hybrid endo-laparoscopic approaches have further widened its use in more advanced diseases. Nevertheless, many of these new innovations are still at their pre-clinical stage. This review focuses on the various innovations in endoscopic surgery, with emphasis on devices and techniques that are currently in human use.

Endoscopic submucosal dissection for treatment of early esophageal cancer and precancerous lesions

Esophageal cancer is the eighth most common form of cancer worldwide. Advances in endoscopic therapy have resulted in dramatic changes in the way early esophageal cancer and precancerous lesions are managed. Endoscopic submucosal dissection (ESD) is a newly developed resection technique that is able to achieve a high R0 resection rate and a low local recurrence rate. Techniques of ESD have become established as standard methods of endoscopic resection. This review addresses some of the recent developments in the field of ESD for early esophageal cancer and precancerous lesions.

Flexible endoscopic robot

Natural orifice transluminal endoscopic surgery (NOTES) is a novel surgical procedure during which abdominal operations can be performed with an endoscope passed through a natural orifice through an internal incision in the stomach, vagina, bladder or colon. NOTES is still evolving and many barriers stand on its way before it can gain acceptance in modern surgical practice. Effective access to the peritoneal cavity, closure techniques of the natural orifice access sites, development of a multitasking platform to accomplish procedures and support for special orientation are only a handful of its known limitations. Although the endoscope and conventional tools are useful for simple procedures, many important and complicated procedures are currently not possible due to limitation of degree of freedom (DOF) of the end effectors. We have developed a Master and Slave Transluminal Endoscopic Robot (MASTER) with nine degrees of freedom (DOF) in end effectors, which are long and flexible so as to enhance endoscopic procedures and NOTES. Using MASTER we have successfully performed endoscopic sub-mucosal dissections (ESD) to segmental hepatectomies in animal models. Thus, the MASTER robotic system shows great potential to perform new surgical procedures that are otherwise not possible with conventional endoscopic tools.

Enhancing proficiency in performing endoscopic submucosal dissection (ESD) by using a prototype robotic endoscope

BACKGROUND AND STUDY AIMS

One of the challenges in performing endoscopic submucosal dissection (ESD) is the lack of counter traction during submucosal dissection. MASTER (Master and Slave Transluminal Endoscopic Robot) was designed to allow performance of complex endoluminal procedures using two arms with excellent control. This study aimed to compare the performance of ESD between endoscopists and novices using MASTER.

METHODS

This is a prospective study comparing the differences in performing ESD using MASTER in an ex vivo porcine stomach model among individuals with or without experience in surgery and endoscopy. Multiple standardized lesions of 20 mm(2) were pre-marked on an ex vivo porcine stomach. Each participant received basic training in controlling MASTER before the ESD procedure. The operative time and size of specimen obtained by each participant were noted.

RESULTS

Nine individuals (three ESD expert endoscopists, three ESD non-expert endoscopists, and three non-clinician novices) participated in the experiment. All participants completed the ESD procedure for en bloc resection of standardized lesions using EndoMASTER without perforation. The mean times (mean ± SD) taken by ESD expert endoscopists, ESD non-expert endoscopists, and novices to complete Robotic ESD were 122 ± 58 s, 203 ± 150 s, and 561 ± 496 s, respectively. There was no statistically significant difference in the mean operative time to complete the ESD between the three groups (P = 0.242). When the performance of the six endoscopists was compared to that of the three novices, the endoscopists took an average of 162 ± 111 s to complete the ESD, while the non-clinicians required an average of 561 ± 496 s (P = 0.085).

CONCLUSIONS

There was a trend to shorter operative time when comparing endoscopists to non-endoscopists in performing ESD using MASTER. The use of MASTER enabled the novice without endoscopy experience to complete the ESD procedure.

Impact of formal training in endoscopic submucosal dissection for early gastrointestinal cancer: A systematic review and a meta-analysis

AIM: To summarize the clinical impact of a formal training for the effectiveness and safety of endoscopic submucosal dissection for gastrointestinal cancer.

METHODS: We searched databases including PubMed, EMBASE and the Cochrane Library and Science citation Index updated to August 2014 to include eligible articles. In the Meta-analysis, the main outcome measurements were en bloc resection rate, local recurrence rate (R0) and the incidence of procedure-related complications (perforation, bleeding).

RESULTS: En bloc resection was high for both, dissecting stomach tumors with an overall percentage of 93.2% (95%CI: 90.5-95.8) and dissecting colorectal tumors with an overall percentage of 89.4% (95%CI: 85.1-93.7). Although the number of studies reporting R0 resection (the dissected specimen was revealed free of tumor in both vertical and lateral margins) was small, the overall estimates for R0 resection were 81.4% (95%CI: 72-90.8) for stomach and 85.9% (95%CI: 77.5-95.5) for colorectal tumors, respectively. The analysis showed that the percentage of immediate perforation and bleeding were very low; 4.96 (95%CI: 3.6-6.3) and 1.4% (95%CI: 0.8-1.9) for colorectal tumors and 3.1% (95%CI: 2.0-4.1) and 4.8% (95%CI: 2.8-6.7) for stomach tumors, respectively.

CONCLUSION: In order to obtain the same rate of success of the analyzed studies it is a necessity to create training centers in the western countries during the “several years” of gastroenterology residence first only to teach EGC diagnose and second only to train endoscopic submucosal dissection.

Future perspective of gastric cancer endotherapy

Endoscopic resection of early gastric cancer (EGC) has proven safety and efficacy, and is the established standard of care in Japan. In the past decade, it is increasingly established worldwide. The endoscopic submucosal dissection (ESD) is superior to endoscopic mucosal resection (EMR) technique as it is designed to provide adequate staging and long-term curative therapy-based on the en bloc R0 specimen irrespective of the size and/or location of the tumor coupled with the reliable pathological specimen. However, ESD is still requiring skilled and experienced endoscopist to perform because of complex procedures, higher complication and causing long-time consuming. The learning and application of these relatively complex endoscopic techniques for EGC has been shown across the world. Thus, a standardized ESD training system is urgently needed to disseminate safe and effective ESD technique to practices with limited ESD experience. In recent years, several innovations providing solutions to easier and safer performance of ESD have emerged. Those increase control of surgical effectors manipulating the target tissue, and enhance performance in complex surgical tasks. Very recently, the use of the laparoscopic and endoscopic cooperative surgery (LECS) procedure is indicated for EGC that would be difficult to treat with ESD. As an ultimate gastric cancer endotherapy with a reasonable surgical time, LECS might be promising method at this stage. The indications for LECS for EGC could be expanded in the future, which could result in increasingly successful gastric cancer treatment.

A state of the art review and categorization of multi-branched instruments for NOTES and SILS

BACKGROUND

Since the advent of Natural Orifice Translumenal Endoscopic Surgery (NOTES) and single incision laparoscopic surgery (SILS), a variety of multitasking platforms have been under development with the objective to allow for bimanual surgical tasks to be performed. These instruments show large differences in construction, enabled degrees of freedom (DOF), and control aspects.

METHODS

Through a literature review, the absence of an in-depth analysis and structural comparison of these instruments in the literature is addressed. All the designed and prototyped multitasking platforms are identified and categorized with respect to their actively controlled DOF in their shafts and branches. Additionally, a graphical overview of patents, bench test experiments, and animal and/or human trials performed with each instrument is provided.

RESULTS

The large range of instruments, various actuation strategies, and different direct and indirect control methods implemented in the instruments show that an optimal instrument configuration has not been found yet. Moreover, several questions remain unanswered with respect to which DOF are essential for bimanual tasks and which control methods are best suited for the control of these DOF.

CONCLUSIONS

Considering the complexity of the currently prototyped and tested instruments, future NOTES and SILS instrument development will potentially necessitate a reduction of the available DOF to minimize the control complexity, thereby allowing for single surgeon bimanual task execution.

Gastric ESD: current status and future directions of devices and training

Endoscopic mucosal resection (EMR) of early gastric cancer, which has been proved to be safe and effective and is the established standard of care in Japan, has become increasingly established worldwide in the past decade. Endoscopic submucosal dissection (ESD) is superior to EMR, as it is designed to provide precise pathologic staging and long-term curative therapy based on an en bloc R0 specimen irrespective of the size and/or location of the tumor. However, ESD requires highly skilled and experienced endoscopists. The introduction of ESD to the Western world necessitates collaborations between Eastern and Western endoscopists, pathologists, and surgeons.

Novel endoscopic therapeutics for early gastric cancer

Gastrointestinal cancers are among the commonest cancers worldwide. Treatment of these cancers at an early stage will result in a significantly better prognosis. Endoscopic submucosal dissection (ESD) is a new method of endoscopic resection that can achieve higher rates of en bloc resection for early gastrointestinal neoplasia. Three retrospective case-control studies showed that ESD achieved significantly higher en bloc resection with lower recurrence rates than endoscopic mucosal resection for treatment of early gastric cancers. Most of the reports on clinical outcomes of ESD were from countries with a high incidence of gastric cancers, including Japan and Korea. The development of ESD has been slow for countries outside Japan and Korea because ESD requires a high level of endoscopic skills, and the dissection was performed single-handedly without assistance. A newly developed robotic endoscopic platform will enhance the performance of ESD through the use of 2 robotic arms: one arm for retraction of the mucosa and the other arm for dissection.