Researchers at Washington DC-based Children’s National Health System have made great strides in robotic surgery. For the first time ever, the team from Sheikh Zayed Institute for Pediatric Surgical Innovation has successfully conducted autonomous robotic soft tissue surgery on a living subject in a standard open surgical setting. According to them, such an approach is not only feasible, but is actually more efficient than conventional clinical techniques.
Recently published in the journal Science Translational Medicine, the study outlines the method adopted by the scientists to perform robotic soft tissue surgeries on both live pigs and inanimate pig tissues. As the team explains, the technology, known as Smart Tissue Autonomous Robot (STAR), aims to replace the surgeon’s hands in the procedure with the specially-designed STAR robotic system, relegating the surgeon to the role of the supervisor. Speaking about the breakthrough, Dr. Peter C. Kim of Sheikh Zayed Institute for Pediatric Surgical Innovation said:
Our results demonstrate the potential for autonomous robots to improve the efficacy, consistency, functional outcome and accessibility of surgical techniques. The intent of this demonstration is not to replace surgeons, but to expand human capacity and capability through enhanced vision, dexterity and complementary machine intelligence for improved surgical outcomes.
Soft tissues are basically the tissues that are responsible for connecting, supporting and surrounding other tissues, organs and structures in the body, including tendons, fascia, ligaments, muscles, nerves, fibrous tissue, blood vessels and capillaries, fat, synovial membranes and so on. Every year, over 44.5 million soft tissue surgeries are performed in the United States alone. Although robot-assisted surgery (or RAS) has become increasingly common these days, hospitals still rely on manual methods for the execution of soft tissue surgeries, mainly because of the plastic and elastic deformations that the tissues continually go through, making surgery quite unpredictable.
To that end, the STAR system uses a highly-specialized tracking technology, based on near infrared florescent (NIRF) markers and advanced 3D plenoptic vision, which generates detailed images of every scene in three dimensions. Furthermore, the tracking system accurately records and reports tissue motion and changes taking place during the surgical procedure. Equipped with an intelligent algorithm, the technology automatically guides the surgical plan, keeping room for real-time adjustments in response to sudden movements and deformations of the soft tissues.
As the researchers point out, STAR uses a variety of other incredibly advanced technologies, including force sensing, precise submillimeter positioning and actuated surgical tools. The system features a lightweight robotic arm fitted with articulated laparoscopic suturing equipment. It possesses flexibility and the freedom to move in different directions. Axel Krieger, a member of the research team added:
Until now, autonomous robot surgery has been limited to applications with rigid anatomy, such as bone cutting, because they are more predictable. By using novel tissue tracking and applied force measurement, coupled with suture automation software, our robotic system can detect arbitrary tissue motions in real time and automatically adjust.
To check the efficacy of the new technology, especially in comparison to currently-available surgical techniques, the scientists conducted two different surgeries on inanimate pig tissue (ex vivo): end-to-end intestinal anastomosis and linear suturing. Following that, the results were compared with the outcomes of the same surgery, when performed manually by a surgeon and also by RAS using daVinci Surgical System.
The team also performed four intestinal anastomosis surgeries on live pigs (in vivo) with the help of the STAR technology. As confirmed by the researchers, all of the subjects survived the procedure with no major complications. When compared with conventional surgeon-executed surgeries, the newly-developed technique was found to be equally and sometimes even more efficient than the former. Kim explained:
We chose the complex task of anastomosis as proof of concept because this soft tissue surgery is performed over one million times in the U.S. annually.
According to the group, the parameters of comparison included consistency and precision of suturing based on average suture spacing, pressure applied, numbers of mistakes that needed the needle to be removed from the tissues, time taken to complete the surgery and finally, lumen reduction, which allowed the team to locate any constriction in the anastomosis.
As the team points out, analysis of the results revealed that, on the whole, STAR system actually outperformed the manual as well as RAS-based techniques, on both live subjects and inanimate porcine tissues. However, while the manually-performed surgery took only eight minutes to complete, the robot-executed procedure took a minimum of 35 minutes. This, according to the scientists, is comparable to clinical laparoscopic anastomosis, which is usually 30 to 90 minutes long, depending on the complexity of the procedure.
The team is currently working on miniaturizing the tools as well as developing more efficient sensors, for wider and more extensive use of STAR. If everything goes according to plan, Dr. Kim believes the technology will be ready for clinical use in less than two years.