Feasibility of full-thickness gastric resection using master and slave transluminal endoscopic robot and closure by Overstitch: a preclinical study. Surg Endosc. 2014;28:319-324. [PMID: 23990156 DOI: 10.1007/s00464-013-3149-3]

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.

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

BACKGROUND AND AIM

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

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 full-thickness resection, indication, methods and perspectives

Minimally invasive surgery has emerged as the dominant theme of modern surgery, in which endoscopic surgery plays a key role. The technique of endoscopic surgery has evolved continuously with extensive research, improving the treatment modalities as well as expanding the indications for its use. As an active perforation endoscopic technique, endoscopic full-thickness resection (EFTR) is mainly used in the treatment of submucosal tumors (SMTs) of the gastrointestinal tract. With decades of evolution, EFTR has gradually developed into a mature endoscopic operation. Based on clinical experience and current research, indications, techniques, clinical outcomes and future perspectives for EFTR are discussed in this paper. We performed a bibliometric study on EFTR literature and showed robust data through a brief meta-analysis on the topic.

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.

Subepithelial tumors: How does endoscopic full-thickness resection & submucosal tunneling with endoscopic resection compare with laparoscopic endoscopic cooperative surgery?

Background and study aims  Endoscopic techniques are rapidly emerging for resection of subepithelial tumors (SETs). Submucosal tunneling for endoscopic resection (STER), endoscopic full-thickness resection (EFTR) and laparoscopic endoscopic cooperative surgery (LECS) are current alternatives to open surgery. In this study, we aimed to compare the three endoscopic techniques. Patients and methods  Consecutive patients who underwent resection of a submucosal esophageal or gastric lesion at several tertiary care centers were included in a dedicated registry over 3 years. Demographics, size and location of resected lesion, histology of specimen, length of procedure, adverse events (AEs), duration of hospital stay, and follow-up data were collected. Results  Ninety-six patients were included (47.7 % male, mean age 62): STER n = 34, EFTR n = 34, LECS n = 280. The lesions included leiomyoma, gastrointestinal stromal tumors (GISTs) and other. The mean lesion size was 28 mm (STD 16, range 20-72 mm). The majority of lesions in the EFTR and laparoscopic-assisted resection group were GISTs. There was no significant difference in clear resection margins, post-procedure complication rates, recurrence rate and total follow-up duration between the groups. However, the LECS group had a procedure time at least 30 minutes longer than STER or EFTR ( P  < 0.01). Total hospital stay for the laparoscopic-assisted resection group was also longer when compared to STER (1.5) and EFTR (1.8) ( P  < 0.01). Conclusions  STER, EFTR, and laparoscopic-assisted resection are efficacious approaches for resection of SETs with similar R0 resection rates, complication rates, and AE rates. Laparoscopic assisted resection appears more time-consuming and is associated with a longer hospital stay.

Endoscopic suturing for GI applications: initial results from a prospective multicenter European registry

BACKGROUND AND AIMS

OverStitch devices (OverStitch and OverStitch Sx; Apollo Endosurgery, Inc, Austin, Tex, USA) are used for a wide range of applications. A European registry was created to prospectively collect technical and clinical data regarding both systems to provide procedural outcomes and to find correlation between procedural characteristics and outcomes. This study shows the initial results of the first 3 years of the registry.

METHODS

Patients who underwent endoscopic suturing from January 2018 to January 2021 at 9 centers were enrolled. Data regarding the disease treated,suturing pattern and outcomes were registered. Technical feasibility (success reaching the target area), technical success (success placing sutures), and clinical success (complete resolution of the clinical issue) were recorded and analyzed.

RESULTS

During the study period, 137 patients (57.7% men) were enrolled with 100% technical feasibility rate. Endoscopic suturing was successfully performed in 136 cases (16.7% with OverStitch Sx), obtaining a technical success rate of 99.3%. No adverse events were recorded. Overall clinical success was 89%. Mucosal defects were sutured in 32 patients (100% clinical success). Leaks/fistulas were treated in 23 patients (64.7% clinical success). The clinical success of stent fixations (n = 38) was 85%. Perforations (n = 22) were repaired with a clinical success of 94.7%. No significant correlation between location, suture pattern or number, and the success was found, except in case of fistulas where fistulas <1 cm treated by a continuous suture were more likely to achieve clinical success in the follow-up (P < .001).

CONCLUSIONS

OverStitch-based suturing is technically feasible regardless of site and method of suturing, with no cases of failure. The overall technical success rate of 99.3% and the clinical outcome success rate of 89% demonstrate that OverStitch technology provides reliable suturing with clinical advantages, especially with fistulas <1 cm.

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.

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.

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.

Evaluation of a robotic arm-assisted endoscope to facilitate endoscopic submucosal dissection (with video)

BACKGROUND AND AIMS

Endoscopic submucosal dissection (ESD) is considered technically difficult and challenging using a conventional flexible endoscope, mainly due to the lack of proper countertraction to expose the submucosal dissection plane. This study aimed to evaluate the feasibility of a traction method using a dexterous robotic arm in ex vivo gastric ESD.

METHODS

ESD was performed in a total of 45 procedures using a portable endoscopic tool handler (PETH) (n = 30) and using the conventional method (n = 15) at various locations in the stomach. For each procedure, the performance data were recorded, including the total procedure time (minutes), incision time (minutes), dissection speed (mm²/minute), and blind dissection rate (%), to enable a comparison of the 2 ESD methods.

RESULTS

The total procedure time was significantly shorter with PETH-ESD than in conventional ESD (23 vs 36 minutes, P = .011). This result is mainly attributed to the dissection speed, which was significantly faster, by more than 2.5 times, using the PETH (122.3 ± 76.5 vs 47.5 ± 26.9 mm²/minute, P < .001). The blind dissection rate was greatly decreased in PETH-ESD (0 vs 20%, P < .001). There was no significant difference in the incision time (6.1 ± 5.0 vs 5.5 ± 2.9 min, P = .612).

CONCLUSIONS

The countertraction method using the PETH significantly improved the dissection speed and reduced blind dissection by enhancing direct visualization of the submucosal plane. With the advantages of multidirectional traction, fine tension control, and regrasping, this new device is expected to improve the performance of ESD and further facilitate advanced endoscopic procedures.

Endoscopic Full Thickness Resection for Gastrointestinal Tumors - Challenges and Solutions

Standard polypectomy, endoscopic mucosal resection, and endoscopic submucosal dissection (ESD) are established techniques for the treatment of gastrointestinal tumors. However, resection of submucosal tumors via ESD often results in low rates of microscopically margin-negative (R0) resection and high rates of perforation. Endoscopic full thickness resection (EFTR) overcomes this adverse event and aids in the therapeutic management of complex tumors.

Multiple techniques for EFTR have been developed, each with its own advantages and disadvantages. Submucosal tunneling and non-exposed techniques are generally preferable, because the layer of overlying intact mucosa reduces the incidence of intraperitoneal contamination by the gastric fluid and dissemination of the tumor cells. However, adoption of EFTR by endoscopists in clinical practice remains low. The major challenge seems to be the technical difficulty in performing laparoscopic and/or endoscopic suturing using the currently available instruments.

We developed a novel robotic endoscopic platform with suturing capabilities to overcome the technical challenges of suturing. This platform allows easy maneuvering and triangulation of the instruments, thus facilitating endoscopic suturing using robotic arms. Our studies have demonstrated that this robotic endoscopic platform with suturing capabilities is an effective and safe method for performing EFTR with endoscopic suturing.

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 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.

A novel technique for removing large gastric subepithelial tumors with ESD method in the subcardia region

Previously, patients with tumors larger than 4 cm in sub-cardia region usually received open gastrectomy. Due to its anatomic features, the cardia is often considered as a contraindicated area for endoscopic resection. Herein, we report a novel technique of endoscopic submucosal dissection (ESD) which facilitates the removal of gastric subepithelial tumors (SMTs) larger than 4 cm in the subcardia and fundus region. This is a retrospective case series of patients with SMTs larger than 4 cm in the subcardia and fundus regions who received the novel procedure of ESD between October 2015 and October 2016. The novel procedure of ESD involved a median linear incision of the mucosa being made in the central area of the tumor, followed by the submucosal dissection. The residual defect was finally closed using titanium endoclips. The endoscopical outcomes, histopathological findings as well as other complications were assessed. Eight patients fulfilled the entry criteria. The mean lesion size was 45.6±7.5 mm (range: 40.0-65.0 mm), and the mean operating time was 83±13 min (range: 60-100 min). The en bloc resection rate was 100%. Although perforations occurred in 5 out of 8 patients, they were successfully closed with endoclips. The median length of inpatient hospital stay was 6 days (range: 5-8 days). No patients needed further gastrectomy. The median follow-up was 36 months and none of the patients developed local recurrence or distant metastasis. The advanced procedure of ESD is feasible and safe for tumors more than 4 cm in the subcardia region. It could be applied as a novel technique for treating patient without surgical interventions.

Endoscopic full thickness resection versus submucosal tunneling endoscopic resection for removal of submucosal tumors: a review article

Submucosal tumors (SMT) are protuberant lesions with intact mucosa that have a wide differential. These lesions may be removed by standard polypectomy, endoscopic mucosal resection (EMR), endoscopic submucosal dissection (ESD), or surgically. However, in lesions that arise from the muscularis propria, full thickness resection is recommended. This can be completed using either endoscopic full thickness resection (EFTR) or submucosal tunneling endoscopic resection (STER). EFTR can be accomplished by completing a full thickness resection followed by defect closure or by securing gastrointestinal wall patency before resection. STER is an option that first creates a mucosal dissection proximal to the lesion to allow a submucosal tunnel to be created. Using this tunnel, the lesion may be resected. When comparing STER to EFTR, there was no significant difference when evaluating tumor size, operation time, rate of complications, or en bloc resection rate. However, suture time, amount of clips used, and overall hospital stay were decreased in STER. With these differences, EFTR may be more efficacious in certain parts of the gastrointestinal tract where a submucosal tunnel is harder to accomplish.

A comparison of submucosal tunneling endoscopic resection and endoscopic full-thickness resection for gastric fundus submucosal tumors

AIM

Both submucosal tunneling endoscopic resection (STER) and endoscopic full-thickness resection (EFTR) are effective methods for gastric fundus submucosal tumors (SMTs). However, there is little data that compares the two methods. The aim of this study was to compare the safety and efficacy of STER and EFTR for the treatment of SMTs in the gastric fundus.

METHODS

Clinical data was retrospectively collected from patients with gastric fundus SMTs who underwent STER or EFTR at our hospital from April 2011 to May 2016. Epidemiological data (gender, age), tumor size, procedure-related parameters, complications, postoperative hospital stay, cost and follow-up data were compared.

RESULTS

A total of 43 patients were enrolled: 15 underwent STER and the remaining 28 cases underwent EFTR. There were no significant differences between the two groups with regard to gender, age, tumor size, en bloc resection rate, operation time, pathohistological results and cost (p > 0.05). However, patients who underwent EFTR had a longer suture time, required a larger number of clips for closure and a prolonged postoperative hospital stay (p < 0.05). No recurrence was noted in either the STER or the EFTR group during a mean follow-up of 12.1 and 22.8 months, respectively.

CONCLUSIONS

The treatment efficacy of STER and EFTR for the treatment of gastric fundus SMTs was comparable. However, STER has some advantages over EFTR in terms of suture time, the number of clips required for closure and postoperative hospital stay.

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.

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.

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.

Experimental Evaluation of the Optimal Suture Pattern With a Flexible Endoscopic Suturing System

BACKGROUND

The ability to perform reliable, secure endoluminal closure of the gastrointestinal tract wall, is a prerequisite to support the progress of the emerging field of endoluminal surgery. Along with advanced clipping systems, flexible endoscopic suturing devices are commercially available. Current systems can replicate traditional surgical suturing patterns in the endoluminal environment. The aim of this study was to evaluate the optimal endoluminal suturing technique using a flexible endoscopic suturing device.

MATERIALS AND METHODS

Procedures were performed on bench-top simulators containing 20 explanted porcine stomachs. A standardized 3-cm full-thickness incision was created on the anterior wall of each stomach using monopolar cautery. The gastrotomy was closed endoscopically using an over-the-scope suturing device (OverStitch, Apollo Endosurgery; Austin, TX). Three different techniques were used: single stitches, figure-of-8 pattern, and running suture. Material consumption and operation time were recorded and bursting pressure measurement of the closure was performed.

RESULTS

No statistically significant differences were identified in suturing time. Suturing time (minutes) was slightly shorter with the figure-of-8 technique (41.14 ± 4.6) versus interrupted (45.75 ± 1.1) versus continuous (51.44 ± 10.0), but the difference was not statistically significant. The number of sutures required was greater in the interrupted group. No significant difference was found in the burst pressure (mm Hg): figure-of-8 (45.85 ± 26.2) versus interrupted (30.5 ± 22.89) versus continuous (32.0 ± 26.5). In the figure-of-8 group, 85.5% of cases were leakproof above 30 mm Hg, while in the other groups only 50% of cases were so.

CONCLUSION

A figure-of-8 suturing pattern seems to be the preferable suturing technique with the endoscopic suturing device.

Comparison between submucosal tunneling endoscopic resection and endoscopic full-thickness resection for gastric stromal tumors originating from the muscularis propria layer

BACKGROUND

Both submucosal tunneling endoscopic resection (STER) and endoscopic full-thickness resection (EFTR) are effective method for treating gastric gastrointestinal stromal tumors (GISTs); however, little is known about the comparison between STER and EFTR. The aim of the study was to compare the safety and efficacy of STER and EFTR for treating gastric GIST.

METHODS

We retrospectively collected the clinical data about patients with gastric GISTs who received STER or EFTR at our hospital from April 2011 to June 2016. Epidemiological data (gender, age), tumor size, procedure-related parameters, complications, length of stay, cost and follow-up data were compared between STER and EFTR.

RESULTS

A total of 52 patients were enrolled, and 20 of them received STER, while the other 32 cases received EFTR. There was no significant difference between the two groups in terms of gender, age, concomitant diseases, tumor size, en bloc resection rate, operation time, complications, pathohistological grade of GIST, hospital stay and cost (P > 0.05). However, patients who received EFTR had a longer suture time and needed more clips to close the gastric-wall defect (STER vs EFTR, 291.5 ± 68.7 vs 380.6 ± 96.9s and 6.0 ± 1.2 vs 7.6 ± 1.6, P < 0.05). No recurrence was noted in the STER and EFTR groups during a mean follow-up of 10.9 and 23.8 months, respectively.

CONCLUSIONS

The treatment efficacy between STER and EFTR for treating gastric GISTs was comparable, and a large-scale, randomized study is necessary for a more confirmed conclusion.

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.

Towards autonomous motion control in minimally invasive robotic surgery

INTRODUCTION

While autonomous surgical robotic systems exist primarily at the research level, recently these systems have made a strong push into clinical settings. The autonomous or semi-autonomous control of surgical robotic platforms may offer significant improvements to a diverse field of surgical procedures, allowing for high precision, intelligent manipulation of these systems and opening the door to advanced minimally invasive surgical procedures not currently possible.

AREAS COVERED

This review highlights those experimental systems currently under development with a focus on in vivo modeling and control strategies designed specifically for the complex and dynamic surgical environment. Expert review: Novel methods for state estimation, system modeling and disturbance rejection, as applied to these devices, continues to improve the performance of these important surgical tools. Procedures such as Natural Orifice Transluminal Endoscopic Surgery and Laparo-Endoscopic Single Site surgery, as well as more conventional procedures such as Colonoscopy, serve to benefit tremendously from the development of these automated robotic systems, enabling surgeons to minimize tissue damage and shorten procedure times while avoiding the consequences of laparotomy.

Endoscopic Submucosal Dissection (ESD) and Related Techniques as Precursors of "New Notes" Resection Methods for Gastric Neoplasms

Endoscopic full-thickness resection for subepithelial tumors is one of the more attractive proposed methods for less-invasive transluminal surgery but remains challenging in terms of safety and feasibility. Currently, laparoscopic endoscopic cooperative surgery is thought to be a more clinically acceptable approach. In targeting cancers, however, more advanced nonexposure techniques are required to avoid the risk of iatrogenic tumor seeding. By combining these techniques with possible regional lymphadenectomy using sentinel node navigation surgery, an ideal minimally invasive, function-preserving gastric resection can be achieved even in possible node-positive cancers. Further development for this type of advanced endoscopic surgery is expected.

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.

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.

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.

Endoscopic full-thickness resection: Current status

Conventional endoscopic resection techniques such as endoscopic mucosal resection or endoscopic submucosal dissection are powerful tools for treatment of gastrointestinal neoplasms. However, those techniques are restricted to superficial layers of the gastrointestinal wall. Endoscopic full-thickness resection (EFTR) is an evolving technique, which is just about to enter clinical routine. It is not only a powerful tool for diagnostic tissue acquisition but also has the potential to spare surgical therapy in selected patients. This review will give an overview about current EFTR techniques and devices.

Natural-orifice transluminal endoscopic surgery

BACKGROUND

Natural-orifice transluminal endoscopic surgery (NOTES) represents one of the most significant innovations in surgery to emerge since the advent of laparoscopy. A decade of progress with this approach has now been catalogued, and yet its clinical application remains controversial.

METHODS

A PubMed search was carried out for articles describing NOTES in both the preclinical and the clinical setting. Public perceptions and expert opinion regarding NOTES in the published literature were analysed carefully.

RESULTS

Two hundred relevant articles on NOTES were studied and the outcomes reviewed. A division between direct- and indirect-target NOTES was established. The areas with the most promising clinical application included direct-target NOTES, such as transanal total mesorectal excision and peroral endoscopic myotomy. The clinical experience with distant-target NOTES, such as for appendicectomy and cholecystectomy, showed feasibility; however, NOTES-specific morbidity was introduced and this represents an important limitation.

CONCLUSION

NOTES experimentation in the preclinical setting has increased substantially. There has also been a significant increase in the application of NOTES in humans in the past decade. Enthusiasm for NOTES should be tempered by the risk of incurring NOTES-specific morbidity. Surgeons should carefully consider patient preferences regarding this new minimally invasive option, as opinions are not unanimously supportive of NOTES. As technical limitations are overcome, the clinical application of NOTES is predicted to increase. It is paramount that, when this complex technique is performed on humans, it is applied judiciously by appropriately trained experts with outcomes recorded in a registry.

Modeling and motion compensation of a bidirectional tendon-sheath actuated system for robotic endoscopic surgery

Recent study shows that tendon-sheath system (TSS) has great potential in the development of surgical robots for endoscopic surgery. It is able to deliver adequate power in a light-weight and compact package. And the flexibility and compliance of the tendon-sheath system make it capable of adapting to the long and winding path in the flexible endoscope. However, the main difficulties in precise control of such system fall on the nonlinearities of the system behavior and absence of necessary sensory feedback at the surgical end-effectors. Since accurate position control of the tool is a prerequisite for efficacy, safety and intuitive user-experience in robotic surgery, in this paper we propose a system modeling approach for motion compensation. Based on a bidirectional actuated system using two separate tendon-sheaths, motion transmission is firstly characterized. Two types of positional errors due to system backlash and environment loading are defined and modeled. Then a model-based feedforward compensation method is proposed for open-loop control, giving the system abilities to adjust according to changes in the transmission route configuration without any information feedback from the distal end. A dedicated experimental platform emulating a bidirectional TSS robotic system for endoscopic surgery is built for testing. Proposed positional errors are identified and verified. The performance of the proposed motion compensation is evaluated by trajectory tracking under different environment loading conditions. And the results demonstrate that accurate position control can be achieved even if the transmission route configuration is updated.

First case of non-exposed endoscopic wall-inversion surgery with sentinel node basin dissection for early gastric cancer

INTRODUCTION

Non-exposed endoscopic wall-inversion surgery (NEWS) is a novel technique of endoscopic full-thickness resection without transluminal access mainly designed to treat gastric cancer. Here, we report a successful case of NEWS with sentinel node basin dissection (SNBD) for early gastric cancer (EGC) with the risk of lymph node metastasis.

PATIENT AND METHODS

A 55-year-old female patient with a 2-cm, diffuse-type intramucosal EGC with ulceration was referred to our hospital for a less invasive gastrectomy based on sentinel node navigation surgery. After obtaining informed consent, NEWS with SNBD was applied. After placing mucosal markings, indocyanine green solution was injected endoscopically into the submucosa around the lesion to examine sentinel nodes (SNs). The SN basin (the area of the left gastric artery), including three stained SNs(#3), was dissected, and an intraoperative pathological diagnosis confirmed that no metastasis had occurred. Subsequently, NEWS was performed for the primary lesion. Serosal markings were placed laparoscopically, submucosal injection was added endoscopically, and circumferential sero-muscular incision and suturing were performed laparoscopically, with the lesion inverted toward the inside of the stomach. Finally, the circumferential mucosal incision was performed, and the lesion was retrieved perorally.

RESULTS

The operation was finished in 270 min without complications. The patient was uneventfully discharged 10 days after the procedure. The final pathological diagnosis was coincident with the pre- and intraoperative assessment.

CONCLUSIONS

We demonstrated the feasibility and safety of NEWS with SNBD with a favorable result. This surgical concept is expected to become a promising, minimally invasive, function-preserving surgery to cure cases of EGC that are possibly node-positive.

Developments in flexible endoscopic surgery: a review

Flexible endoscopy is increasingly developing into a therapeutic instead of a purely diagnostic discipline. Improved visualization makes early lesions easily detectable and allows us to decide ad hoc on the required treatment. Deep enteroscopy allows the exploration of even the small bowel - for long a "white spot" for gastrointestinal endoscopy - and to perform direct treatment. Endoscopic submucosal dissection is a considerable step forward in oncologically correct endoscopic treatment of (early) malignant lesions. Though still technically challenging, it is increasingly facilitated by new manipulation techniques and tools that are being steadily optimized. Closure of wall defects and hemostasis could be improved significantly. Even the anatomy beyond the gastrointestinal wall is being explored by the therapeutic use of endoluminal ultrasound. Endosonographic-guided surgery is not only a suitable fallback solution if conventional endoscopic retrograde cholangiopancreatography fails, but even makes necrosectomy procedures, abscess drainage, and neurolysis feasible for the endoscopist. Newly developed endoscopic approaches aim at formerly distinctive surgical domains like gastroesophageal reflux disease, appendicitis, and cholecystitis. Combined endoscopic/laparoscopic interventional techniques could become the harbingers of natural orifice transluminal endoscopic surgery, whereas pure natural orifice transluminal endoscopic surgery is currently still in its beginnings.

What if endoscopic hemostasis fails?: Alternative treatment strategies: surgery

Management of bleeding peptic ulcers is increasingly challenging in an aging population. Endoscopic therapy reduces the need for emergency surgery in bleeding peptic ulcers. Initial endoscopic control offers an opportunity for selecting high-risk ulcers for potential early preemptive surgery. However, such an approach has not been supported by evidence in the literature. Endoscopic retreatment can be an option to control ulcer rebleeding and reduce complications. The success of endoscopic retreatment largely depends on the severity of rebleeding and ulcer characteristics. Large chronic ulcers with urgent bleeding are less likely to respond to endoscopic retreatment. Expeditious surgery is advised.

Endoscopic stitching: techniques and indications

PURPOSE OF REVIEW

Endoscopic suturing has evolved dramatically over the past decade. Early suturing devices had significant limitations preventing widespread use. Newer devices, though not perfect, have overcome many of these limitations. The purpose of this review is to discuss the techniques and current indications for endoscopic suturing.

RECENT FINDINGS

In addition to technological advances, the indications for endoscopic suturing continue to increase in number. Recent literature has demonstrated successful use of endoscopic suturing for the treatment of procedural adverse events such as leaks, perforations, and fistulas, but newer indications such as anchoring of self-expandable metal stents and bariatric therapy, both primary and secondary, have also been proven to be successful.

SUMMARY

The availability of endoscopic suturing will likely increase in the coming years and will not be limited to expert centers. Currently available devices require technical expertise but are improved over previous devices.