WEO Newsletter: Current state and future development of robotic endoscopy

Abstract

Hon Chi YIP MBChB (CUHK), FRCS(Edin)¹ and Philip Wai Yan, CHIU MD (CUHK), MBChB (CUHK), FRCS(Edin)²

¹Division of Upper GI & Metabolic Surgery, Department of Surgery, Faculty of Medicine, The Chinese University of Hong Kong and ²Multi-Scale Medical Robotics Center, InnoHK

Development of flexible robotic endoscopy has proven to be a much more challenging task than rigid robotic surgical system. The main hurdles that need to be overcome for such a platform include the requirement of much smaller instruments within the GI lumen, as well as the intuitive movement of these instruments within a tortuous gastrointestinal tract. Existing robotic endoscopic systems could be divided into two main types: completely robotized endoscopic systems and robotic add-on system for existing endoscopic platforms. Among these systems, only a few have successfully reported results of human trials, while the majority of the others still remain at pre-clinical stage.

EndoMaster EASE system is a robotic endoscopic platform that consists of an endoscope mounted to a patient side cart, where two 4 mm robotic instruments (one electrosurgical dissector and one grasper) could be inserted into the target site through the endoscopy channel. The primary endoscopic surgeon controls the robotic instruments from the console unit, with both instruments allowing movement up to 9 Degree of Freedom (DOF). The prototype of the system was first applied in 5 human cases of gastric ESD in 2011 (1). Following system modification into a fully robotic endoscopic platform, a prospective single arm study was recently reported for 43 patients who underwent colorectal ESD using the system (2). Technical success was achieved in 86.1% of the patients, with en-bloc resection rate of 94.6% among those with successful procedure. While the results of the trial are encouraging, further questions remain including the need to downsize the system, the cost and benefit when compared with conventional ESD, etc.

EndoQuest Robotics Endoluminal Surgical (ELS) System is another robotic endoscopic platform that has reached the stage of clinical trials. Targeting solely at transanal endoscopic procedure at the sigmoid and rectum, the system consists of a 2.2 cm diameter 4-DOF Steerable Overtube (Previously named as Colubriscope), which allows insertion of one 6 mm flexible endoscope and two 6 mm robotic instruments with 7-DOF.

The system has demonstrated feasibility of partial thickness colorectal resection and suture closure in an ex-vivo animal study (3). Human clinical trial is currently underway for resection of lesions in sigmoid and rectum, and the results are eagerly awaited.

Flex Robotic System (Medrobotics) utilizes a robotized endoscope with two flexible mechanical arms. The 28 mm diameter flexible robotic endoscope is controlled at the console with a joystick, with two working channels allowing passage of mechanically controlled needle-knife and grasper. Originally designed for transoral surgery, the system was refined for transanal use up to 25 cm from anal verge. Successful full thickness resection and suture closure in a patient with rectal lateral spreading tumor was previously reported (4). Further modification of the system to enable deeper colonic intubation and use in upper GI tract is in progress.

Other complete robotic systems under development include Endoluminal Assistant for Surgical Endoscopy (Previously known as STRAS) (5), I2 Snake robotic platform (Hamlyn Centre for Robotic Surgery) (6) and K-FLEX (EasyEndo Surgical) (7). These devices offer similar concept of robotic instruments inserted through channels of an overtube / videoscope to allow operation within the GI lumen but has not been applied in clinical setting yet.

Robotic add-on system utilizes the conventional endoscopy unit with a robotic manipulator attaching to the distal end of the endoscope. Robot for Surgical Endoscope (ROSE, Endorobotics) is a device that could provide multi-directional countertraction by rotating around the circumference at the tip of the endoscope in addition to a 3-DOF movement (8, 9). The standard grasping device has recently been licensed for human use in Korea, while additional functions such as endoscopic suturing are also being developed.

To date, a few clinical trials have confirmed the diagnostic and therapeutic potential for robotic endoscopy in the field of bronchoscopy and gastrointestinal endoscopy (2, 10). Flexible endoluminal robotics can be applied to enhance the endoscope as well as therapeutic devices, for example EndoMaster EASE system for performance of colorectal ESD using two robotic arms (2). In future, the developmentsin flexible robotics will focus on areas including: 1. Automated robotic endoscopy for diagnosis; 2. Robotic endoluminal devices for tissue approximation; 3. Teleoperation and Telementoring and 4. AI co-pilot in Robotic Endoscopy. Colonic cancer screening programs have been implemented by governments around the world. However, the rate of adoption of screening colonoscopy by population is still low (11). One of the reasons is the lack of endoscopists in handling large number of screening colonoscopies, as well as the need of deep intravenous sedation due to pain induced during colonoscopy. Valdastri e al developed a magnetic guided robotic colonoscopy system which allow performance of screening colonoscopy with less pain (12). Extracorporeal magnetic guidance allowed less pain when the colonoscope navigated through flexures of colon. Artificial intelligence (AI) will be able to provide guidance in combination with the magnetic force to further enhance this navigation (13).

Currently, endoscopic submucosal dissection (ESD) is the first targeted procedures for most of the novel endoluminal robotic systems (2-4, 8, 9, 14, 15). This is likely related to the technical challenges in performance of ESD, as well as the fact that ESD is a standardized procedure for treatment of early GI cancers. However, future development of endoluminal surgery will be enhanced with robotic tissue approximation devices including endo-suturing and endo-stapling (16). Robotic suturing will extend the horizon of clinical applications for endoluminal robotics from endoscopic sleeve gastroplasty (17) to endoscopic full thickness resection (18, 19), and flexible robotics will provide more degree of freedom towards precision in endoluminal suturing.

Mesot et al reported the performance of real-time teleoperated magnetic endoscopy in porcine model between Zurich and Hong Kong (20). The gastroscopy was performed with extracorporeal magnetic guidance, while the precise magnetic field allowed the performance of retroflexed motion without mechanical assistance from the endoscope. In future, AI combined with magnetic guided endoscope will unleash the potential for semi-automation or total automation in diagnostic endoscopy. This will provide opportunities for scaling up the capability of diagnostic endoscopy especially for screening, including colonoscopy and oesophagogastroduodenoscopy. AI will also be able to provide guidance and serve as co-pilot for endoscopists during advanced therapeutic endoscopy including ESD (21). Currently, preclinical study has demonstrated the efficacy of AI in outlining the safety direction of submucosal dissection during ESD procedure.

In summary, the field of therapeutic endoscopy has been drastically expanding over the past decade. The design of the current endoscope has limited the potential application in more complex tasks such as tissue retraction, suturing and tissue approximation etc. With the development of novel robotic endoscopic platforms as well as integration with artificial intelligence, it is expected that a new era of endoscopic surgery would come into reality where endoscopists would need to adapt to the novel technology and explore the unlimited possibilities of endoluminal robotic surgery.

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