Surgeons once made incisions large enough to get to a gallbladder or other organs by using conventional tools they held in their hands. Today, many sit at a computer console instead, guiding robotic arms that enter the patient's body through small openings not much larger than keyholes.

But even this minimally invasive surgery usually requires multiple incisions: one for the camera system showing the way to the surgeon at the console, and others for each robotic arm that cuts and stitches.

Now there are robotic systems - one on the market, others in development - that are even less intrusive. They require only a single, small incision through which the robotic arms and camera enter.

This could lead to faster recovery, said Dr. Michael Hsieh, a Stanford University professor and a urologist at Lucile Packard Children's Hospital and Stanford Hospital in California. "There's only one wound to heal with this procedure, rather than three," he said.

Dr. Hsieh, who performs abdominal surgery, uses minimally invasive techniques that typically now require three incisions. His patients generally go home a day or two after surgery, he said, "but I think they would recover more quickly if I could reduce my multiple incisions to just one." He added, "And there will be less scarring, or even no scarring, if you enter through the navel."

He will soon have a chance to try out the new method on his patients. Stanford Hospital is buying a system from Intuitive Surgical called Single-Site that requires one incision of about 2.5 centimeters. The system, approved by the United States Food and Drug Administration only for gallbladder removal, is used as an addition to a basic robotic system from Intuitive, known as the da Vinci Si.

The Si costs $1.3 million to $2.2 million, said Angela Wonson, a spokeswoman for Intuitive, based in Sunnyvale, California. The Single-Site can add $60,000 or more to the cost.

Another surgical robotic system, now in development, uses a 15-millimeter incision. The robot was designed by Drs. Dennis Fowler and Peter Allen of Columbia University and Dr. Nabil Simaan of Vanderbilt University in Nashville, Tennessee. Once in the body, it unfolds to reveal a camera system and two snakelike arms that perform the surgery. The system is licensed to Titan Medical in Toronto.

Minimally invasive surgery through one incision can also be performed with long, thin laparoscopic tools that surgeons wield as they watch a video monitor.

Dr. Hsieh envisions a benefit he has long dreamed about. "We may get to the point where we do outpatient, scarless robotic surgery," he said.

The New York Times