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So Why Use Robots?

Along with helping surgeons perform minimally invasive surgical tasks, robots have superhuman capabilities that make surgery easier, says Paul Massimiano, M.D., a cardiac surgeon at Inova Fairfax Hospital in Virginia. He has performed thoracic and experimental cardiac surgery using the da Vinci system.

"Robotic arms don't have tremor," so they can remain steady at all times, Massimiano says. Robotic wrists make it easier for surgeons to manipulate tissue and work from all kinds of angles. "I can reach around and get to places that would be harder to get to otherwise," Massimiano says.

Robotic surgical systems can also improve depth perception, giving surgeons three-dimensional vision, compared with the two-dimensional vision they would normally get with endoscopic procedures. And the surgical field can be magnified so that millimeter-sized veins appear as big as pencils.

Compared with the long instruments used in endoscopy, robotic surgical systems use smaller instruments that provide increased range of motion. Celeste Hollands, M.D., chief of pediatric surgery at Louisiana State University's Health Sciences Center in Shreveport, sees this as a huge benefit in her work with small children.

"A baby's abdomen is only about the size of your hand, so the instruments need to be small enough," Hollands says. She used Zeus' 5-millimeter scope to help correct stomach blockages in three babies earlier this year.

"I had to cut manually," she says, "but ZEUS stabilized the intestines for me and spread stomach muscles. I was able to easily move back and forth from manipulating ZEUS to using a standard laparoscopic procedure."

Robotics also offers motion scaling, which means that a surgeon's gross hand movements can be reduced to fine movements, allowing for accuracy in tight spaces. For example, with motion scaling, one inch of movement by the surgeon results in a quarter-inch movement by the robotic surgical instruments.

Hollands only had to make a tiny nick in the abdominal wall to perform the surgeries, and the babies' scars were hardly noticeable. "When they came back into the office, I had to look hard to figure out where the scars were," she says.

Robotic Heart Surgery

Cardiac surgery was the last area to adopt endoscopic procedures because of the complexity of the procedures involved. But starting around 1995, heart surgeons were successful in using Computer Motion's AESOP to help repair and replace narrowing or leaking cardiac valves with small incisions.

"It was video direction of operations via a voice-activated robotic camera that introduced cardiac surgeons to the robotic age," says Marco Zenati, M.D., assistant professor of surgery at the University of Pittsburgh.

W. Randolph Chitwood Jr., M.D., chairman of the department of surgery at East Carolina University in Greenville, N.C., says he and his colleagues have done more than 200 mitral valve repairs using AESOP.

"This has allowed our surgeons to have greater flexibility in repairing complex mitral valve problems, as well as to replace valves," Chitwood says. "In fact, we have been able to work deep within the heart using AESOP to close fistulas between coronary arteries and the cardiac chambers — all done using voice-activated AESOP camera control and secondary vision from a monitor."

AESOP is cleared for use as a voice-activated camera in heart surgery. But complete robotic heart surgery, which is commonly done in Europe and Canada, is considered experimental in the United States. Both da Vinci and ZEUS are being used in clinical trials studying endoscopic cardiac surgery. Through what's known as an investigational device exemption, companies can conduct FDA-approved clinical trials to collect safety and effectiveness data on robotic heart surgery.

The goal is to avoid the tissue damage that comes with making a foot-long incision through the sternum and opening up the chest, which has been the typical procedure for open-heart surgery. With robot-assisted heart surgery, surgeons are able to operate through three small incisions between the ribs. Preliminary data suggests that recovery time may be shortened with robotic-assisted heart surgery.

In May 2000, Chitwood used da Vinci to perform the first complete mitral valve repair in the United States as part of a multi-center, FDA-approved trial sponsored by East Carolina University and Intuitive Surgical. A total of 10 centers are participating, including the University of Southern California in Los Angeles, Columbia Presbyterian Medical Center in New York, Brigham and Women's Hospital in Boston, and Inova Fairfax Hospital in Fairfax, Va. Patients in the trial have defective mitral valves repaired with assistance from the da Vinci system. Chitwood and his colleagues have done 41 mitral valve repairs with da Vinci with no major problems to date.

"Our initial experience shows this can be done with good patient outcomes," says Chitwood, who serves as the trial's principal investigator. "Our patients have had better cosmetic results and spent less time in the intensive care unit and hospital compared to conventional mitral valve surgery, which cuts the breastbone in half."

While East Carolina University leads the multi-center mitral valve trial in which da Vinci is being evaluated, Columbia will lead a multi-center trial on coronary artery surgery with da Vinci. Previous clinical trials investigating robotic assistance in coronary surgery appear promising, surgeons say. For example, Ralph Damiano of Washington University in St. Louis has reported successful results in U.S. clinical trials involving coronary artery bypass surgery using the ZEUS system. This operation typically requires stopping the patient's heart and using a heart-lung machine, which maintains circulation and takes over breathing for the patient.

In April 2001, Zenati and his colleagues used ZEUS during a beating-heart cardiac bypass operation on a 63-year-old man. This was part of an FDA-approved multi-center trial investigating whether ZEUS can be safely used to help surgeons connect the left internal mammary artery graft to the left anterior descending artery.

"This is something that can't be done with standard laparoscopy," Zenati says. "We're talking about connecting tiny blood vessels that are only 2 millimeters, so there is little margin for error."

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