Autonomous robot performs soft-tissue surgeryMay 5(AZINS) The machine, called the Smart Tissue Autonomous Robot (STAR), does not replace the need for a skilled surgeon, but acts as a tool to improve the accuracy of stitching, said the report in the journal Science Translational Medicine.

The study showed STAR outperformed expert surgeons and a well-known robotic surgery tool already on the market, called the da Vinci robot, which is held in the surgeon's hand and used to perform surgeries such as hysterectomies through a few small incisions.

Until now, robotic surgeries have largely relied on the expertise of the surgeon and outcomes have varied according to the doctor's skill, researchers say.

Soft tissue is particularly complicated because it is malleable and movable.

But being able to improve on such surgeries "could potentially reduce complications and improve the safety and efficacy of soft tissue surgeries, about 45 million of which are performed in the US each year," according to the study led by doctors at the Children's National Health System in Washington, DC and Johns Hopkins University in Baltimore, Maryland.

The STAR was tested in a procedure called anastomosis, which comes after a surgeon has cut open the patient's body and completed the main goal of the surgery -- for instance by removing a tumour from the bowel -- and is then reconnecting two sections, "like trying to put together a garden hose, which has been cut," explained co-author Ryan Decker.

Anastomosis is performed more than a million times each year in the United States, for surgery involving the intestines, as well urologic and gynecologic operations.

As many as 30 percent of gastrointestinal anastomoses "are complicated by leakage, strictures, and stenosis," according to a statement from the Children's National Health System.

For the current study, surgeons made fluorescent markings on the vessels to be sewn, and the robot followed them, showing it could make more consistent and evenly spaced stitches, or sutures, than a human surgeon, Decker told reporters.

"If you have a more consistent and a more, well-tensioned, evenly spaced suture around this garden hose, it's going to be able to withstand a higher burst pressure," Decker said.

"That's in fact what happened with our anastomosis. They were able to withstand a higher burst pressure than surgeons performing the same task."

The pigs survived the surgery and showed no complications a week later.

Researchers stressed that surgeons were keeping a close eye on the machine as it worked, and it could be quickly stopped if any error were to occur.

The STAR system is likely years away from widespread use. Researchers expect there will be a need for clinical trials to assess its safety in humans before it can approved by regulators.