Are robots superior to surgeons?
Researchers have developed a robotic arm to conduct suturing during soft tissue surgery, which has the potential for improved patient safety due to a reduction in surgical errors and increased efficiency.
Suturing soft tissue can be challenging even for a skilled surgeon--the tissue can move and change shape in complex ways as stitching occurs, requiring the ability to keep sutures tightly and evenly placed. Not surprisingly, leakage along the seams is a significant problem in nearly 20 percent of colorectal surgeries and 25 to 30 percent of abdominal surgeries.
The Smart Tissue Automation Robot (STAR) features a 3D imaging system and a near-infrared sensor to spot fluorescent markers along the edges of the tissue to keep the robotic suture needle on track and consistent in its placement.
Working with researchers affiliated with the Children’s National Health System in Washington, D.C., Simon Leonard, a computer scientist at Johns Hopkins University and an assistant research professor in JHU’s Whiting School of Engineering, programmed STAR to precisely and repeatedly stitch together pieces of soft tissue.
“There’s a large amount of variability for surgeons,” said Leonard. “It’s quite amazing to see the wide range of quality that you can get from different surgeons.”
A study published last week in the journal Science Translational Medicine compared STAR’s robotic sutures with the work of five surgeons completing the same procedure using three methods: open surgery, laparoscopic and robot-assisted surgery. Specifically, researchers compared the consistency of suture spacing, pressure at which the seam leaked, mistakes that required removing the needle from the tissue or restarting the robot, and completion time.
“Surgeons tested STAR against manual surgery, laparoscopy, and robot-assisted surgery for porcine intestinal anastomosis, and found that the supervised autonomous surgery offered by the STAR system was superior,” states the article. “Despite dynamic scene changes and tissue movement during surgery, we demonstrate that the outcome of supervised autonomous procedures is superior to surgery performed by expert surgeons and [robot-assisted surgery] techniques in ex vivo porcine tissues and in living pigs. These results demonstrate the potential for autonomous robots to improve the efficacy, consistency, functional outcome, and accessibility of surgical techniques.”
“It’s very similar to what robots have been doing on manufacturing assembly lines for years,” adds Leonard. “They can do the same thing over and over again and be incredibly consistent. Likewise, our system can perform the same task over and over again with the same amount of quality.
“Surgeons tested STAR against manual surgery, laparoscopy, and robot-assisted surgery for porcine intestinal anastomosis, and found that the supervised autonomous surgery offered by the STAR system was superior."
At the same time, Leonard acknowledges that STAR was “significantly slower” than open and robot-assisted surgery, but comparable to the laparoscopic procedure. The robotic procedure lasted 35 to 57 minutes, while the open surgery took eight minutes. Still, he insists that by all other measures the robot’s performance was comparable or better than the surgeons in the study.
Leonard, however, is quick to emphasize that STAR is not intended to replace surgeons but rather is envisioned to expand human capacity and capability. While it is designed to operate without hands-on guidance from a surgeon, he says the robotic surgical system is meant to be constantly under a surgeon’s supervision during these procedures and ultimately it's the surgeon who “calls the shots.” Leonard declined to guess when STAR might actually find a home in ORs at the disposal of surgeons.
Although limited robotic automation is currently used in surgeries involving rigid structures such as bones, he argues that those are much easier to hold still during procedures than soft tissues which can be slippery and move during suturing. And, animal studies with STAR are a far cry from human studies and FDA approval, Leonard concludes—though the potential is there for such a transition.