Stanford Report Online



Stanford Report, November 15, 2000
Robots deemed to play expanding role in delicate surgeries

BY CHARLES CLAWSON

Two-year-old Alexander Cumming's congenital heart defect was repaired by a robot. But the robot, named Aesop, was not on its own. Under the control of Michael Black, MD, chief of cardiac surgery at Lucile Packard Children's Hospital, Aesop fixed the heart problem in three hours. When Alexander awoke he required no respirator, his cheeks were pink, and the only indication that he'd undergone heart surgery was a piece of tape the size of a Band-Aid on his chest -- all testimony to the coming age of medical robotics.

The robot is shaped like a black plastic arm and projects a fiber optic camera on a wire rod. The system moves according to Black's voice commands and transmits images to a video monitor. The images are similar to those taken by conventional laparoscopic equipment, but because the camera is not hand-held (as standard laparoscopic equipment is) the images are exceptionally clear, not blurred or shaky. The minimally invasive technique allows heart surgery with far less trauma, recovery time and scarring than traditional methods of open-heart surgery.

"We're able to repair complex defects through a two-inch incision rather than the traditional sternotomy, which splits the breastbone from top to bottom," said Black. "As a result, the child recovers much faster and leaves the hospital sooner, usually in only two days. There's less pain, fewer complications, and better cosmetic results because the scar is smaller and less extensive." Traditional open-heart surgery requires a hospital stay of five to seven days and results in a prominent scar from neck to belly button.

Black began doing minimally invasive cardiac surgery when he was at Toronto's Hospital for Sick Children. There he treated relatively simple atrial-septal defects. Now he and a Stanford team address complicated repairs such as muscular apical-ventricular-septal defects, heart tumors, valvular lesions and obstructive lesions. To date, Black and the Stanford team have performed heart repairs on several hundred children.

"So far, we've never had to readmit a child after discharge or extend the incision because the surgery wasn't successful," said Black.

The surgery requires an exceptionally and uniquely talented surgeon. When operating Aesop, Black is outfitted with headgear that includes magnifying lenses and a microphone for communicating with the robot. Aesop responds only to Black's voice and follows commands such as move up, move down, or stop. The movements are very smooth and typically more precise than a human's. The fiber optic camera is inserted through a two-inch incision in the patient's chest, transmitting to a video monitor across the table from Black, projecting the image that he works from. Such a small incision allows the team's anesthesiologist, Greg Hammer, MD, to eschew the traditional method of general anesthesia for a combination of an epidural and light general anesthesia, which contributes to less post-operative pain and quick recovery.

At present more than 500 centers around the country are using Aesop, which was the first robot approved by the Food and Drug Administration for surgery. Black, though, is one of only a few surgeons in the world using robotics regularly on children. When he began using the method on children, some doctors were critical in light of the excellent results most children's hospitals achieve with traditional methods. "Some older doctors thought it was unsafe to maneuver through such a small hole," Black said.

Yet it's likely that Aesop is only the first step in robotics designed to be less invasive and more precise. The next generation machine, called Zeus, is being developed by Santa Barbara-based Computer Motion Inc. (the creators of Aesop) and Mountain View's Intuitive Surgical Inc. Zeus will operate on a patient without requiring a physician be present in the room. Theoretically, the surgeon can operate the robot from thousands of miles away using a computer and a joystick. Zeus, which costs $875,000 and is expected to be approved by the FDA this fall, will be studied by Black for use in pediatric surgery.

A time may come when the entire operating room is controlled by a wireless system of voice or computer command for lights, bed and various robotic instruments. Black also hopes to develop a camera that sees through blood.

For now he'd like to see current advances adopted. "It's clear that what we're doing here is safe and effective," said Black. "Now what we want to do is teach other surgeons around the country how to perform operations the same way we're doing them at Stanford. That will make it possible for that many more kids to benefit."