Tech Briefs

Robot plans and performs surgical suturing

Children’s National Health System, Washington, DC

Surgeons and scientists at the Children’s National Health System’s Sheikh Zayed Institute for Pediatric Surgical Innovation have demonstrated that supervised, autonomous robotic soft tissue surgery on a live subject in an open surgical setting can outperform standard clinical techniques.

Fig. 1 – Smart Tissue Autonomous Robot. (Credit: Sheikh Zayed Institute for Pediatric Surgical Innovation, Children’s National Health System)

Their research reports the results of soft tissue surgeries conducted on both inanimate porcine tissue and living pigs using a proprietary robotic surgical technology called Smart Tissue Autonomous Robot (STAR), developed at Children’s National. This technology utilizes the surgeon as a supervisor, with soft tissue suturing autonomously planned and performed by the STAR robotic system. Soft tissues include tendons, ligaments, fascia, skin, fibrous tissues, fat, synovial membranes, muscles, nerves and blood vessels. Currently more than 44.5 million soft tissue surgeries are performed in the US each year.

The research was performed to show that autonomous robots can improve the efficacy, consistency, functional outcome and accessibility of surgical techniques, not to replace surgeons, but to use the enhanced vision, dexterity, and complementary machine intelligence to improve surgical outcomes.

How It Works

While robot-assisted surgery (RAS) has been increasingly adopted in healthcare settings, soft tissue surgery has remained entirely manual, largely because the unpredictable, elastic, and plastic changes in soft tissues that occur during surgery, requiring the surgeon to make constant adjustments.

To overcome this challenge, STAR uses a tracking system that integrates near infrared fluorescent (NIRF) markers and 3D plenoptic vision, which captures light field information to provide images of a scene in three dimensions. This system enables accurate, uninhibited tracking of tissue motion and change throughout the surgical procedure. This tracking is combined with an intelligent algorithm that guides the surgical plan and autonomously makes adjustments to the plan in real time as tissue moves and other changes occur. The STAR system also employs force sensing, sub-millimeter positioning and actuated surgical tools. It has a bed-side lightweight robot arm extended with an articulated laparoscopic suturing tool for a combined eight degrees-of-freedom robot. (See Figure 1)

To compare the effectiveness of STAR to other available surgical procedures, the study included two different intestinal surgeries performed on inanimate porcine tissue, linear suturing, and an end-to-end intestinal anastomosis, which involves connecting the tubular loops of the intestine. The results of each surgery were compared with the same surgical procedure conducted manually by an experienced surgeon, by laparoscopy, and by RAS with the da Vinci Surgical System.

The Children’s National research team conducted four surgeries on living pigs using STAR technology and all subjects survived with no complications. The study compared these results to the same procedure conducted manually by an experienced surgeon using standard surgical tools.

All surgeries were compared based on the metrics of anastomosis including the consistency of suturing based on average suture spacing, the pressure at which the anastomosis leaked, the number of mistakes that required removing the needle from the tissue, completion time and lumen reduction, which measures any constriction in the size of the tubular opening.

The comparison showed that supervised autonomous robotic procedures using STAR proved superior to surgery performed by experienced surgeons and RAS techniques, whether on static porcine tissues or on living tissue. In the comparison using living subjects, the manual control surgery took less time, 8 minutes versus 35 minutes for the fastest STAR procedure, however researchers noted that the duration of the STAR surgery was comparable to the average for clinical laparoscopic anastomosis, which ranges from 30 minutes to 90 minutes, depending on complexity of the procedure.

For more information, visit http://childrensnational.org.