A new study, published in Science Translational Medicine, details how a robotic arm has performed the first automated intestinal surgery, using pig intestine. According to researchers at the Children’s National Medical Center’s (CNMC) Sheikh Zayed Institute, the robot proved to be more successful than human surgeons on a couple of points during the test. 

The Smart Tissue Autonomous Robot, or STAR, is a robotic surgical system that scientists are trying out in hopes of eventually improving the efficacy of human surgeries. In this trial, the robot was supervised by humans. With this model, the scientists anticipate a future where humans work cooperatively with robots rather than being completely replaced by them.

Automatons are already being used for surgeries that involve rigid tissues, such as bones. The scientists in this study, however, were more interested in how a robot would be able to handle the precariousness of a tissue as soft as pig intestine. Soft tissues are more slippery and therefore move about more easily. This surgery, called an intestinal anastomosis, requires the surgeon to suture pieces of soft tissue together. The challenge is two-fold – not only are the tissues soft and extremely pliable, the sutures must also be placed strategically to prevent subsequent leakage. “The procedure is like trying to put together a garden hose which has been cut,” says study assistant Axel Krieger. He says it has to “be strong enough so that when it increases in pressure, the garden hose will not leak.”

STAR’s needle followed fluorescent markers on the periphery of the pig intestine. A human surgeon supervised STAR’s every move, without any physical intervention. The surgeon approved each suture before STAR put it in place. Because the tissue is soft, it changes in response to the stitches inserted. STAR, therefore, had to respond to and adapt to these changes while it made its sutures. STAR received new information from the computer system, which prompted it to change its suturing methods in response to changing stimuli. You can check out STAR in action.

So, how did STAR do? The researchers got surgeons to perform the same procedures on pig intestine using one of the following methods: open surgery, laparoscopy and the robot-assisted da Vinci Surgical System, a U.S. program where robots work alongside human surgeons. 

Researchers took notes on the consistency and resistance of sutures, as well as accuracy. On consistency, STAR’s sutures were more consistently spaced than surgeons who used the other methods. Consistent spacing is a great indicator of suture strength. Scientists were also curious on just how much pressure these sutures could withstand. They found that STAR’s sutures were just as good as the surgeon’s in being able to tolerate the same maximum pressures. Not only did STAR make resistant, strong sutures, it also had to be corrected fewer times than the FDA-approved robot-assisted da Vinci system.

The most significant drawback of the system was how long each procedure took. Because STAR was being supervised by a human who had to approve each suture before it was made, this method took a much longer time when compared with the human surgeons. But study assistant Krieger says that the robot can actually be run quite quickly. “…[I]n this study, we really focused on the mission and the outcome, so we didn’t run it as fast as we could,” he comments.

It may take a while for STAR to be approved for robot-assisted surgery. Take the da Vinci system, for example. According to some studies, not only does the da Vinci system have just as many complications as human-performed surgeries, it’s also much more expensive. People have actually sued the makers of the da Vinci System for doctors poorly trained on operating da Vinci. Not too long ago, TransEnterix, another robot-assisted surgical system, failed to get the green light from the FDA.

But the makers of STAR are hopeful that STAR’s promise can be translated into the clinic. It is not their goal to have robots replace human surgeons, but to have both surgeons and robots work together to save lives in the future.


I am a medical student at the University of Toronto. I enjoy meeting new people, drawing and writing.