Revolutionary Developments in Open Heart Surgery Procedures
This report was reviewed for medical and scientific accuracy by Louis L. Battey, MD, SACC , Cardiology of Georgia.
Quite possibly two of the most revolutionary current-day examples of "convergence" are Aesop and his "son," Zeus, both of which will almost certainly change surgery within the next five to 20 years. Not fables, Aesop and Zeus are operating room robots that are currently assisting a handful of elite surgeons around the world in performing some of the most difficult and exacting surgical procedures known to modern medicine.
The brain-children of Yulun Wang, PhD, Founder and Chief Technical Officer, Computer Motion, Santa Barbara, California, the two robots are barely a year old. They already attended their first Republican National Convention in Philadelphia this past July, where their skills were demonstrated by Dr. James Luketich, Assistant Professor of Surgery and Section Head of Thoracic Surgery, University of Pittsburgh Medical Center (UPMC). Centerpieces of an advanced healthcare technology event honoring Senator Arlen Specter, Aesop and Zeus proceeded to show convention attendees why they serve as cornerstones of the advanced minimally invasive surgery program at UPMC and a handful of other leading teaching institutions in the United States, Canada, and Europe.
The robots' rise to prominence in medical circles has been swift and shows no sign of abating. What excites surgeons like Drs. Stephen Colvin and Eugene Grossi, two leading cardiac surgeons at the New York University Medical Center who have pioneered the use of Aesop and Zeus in cardiac surgery, is the robots' ability to expand the skills of surgeons beyond human limits-an enhancement that suggests patients will do better, heal faster, and return home sooner.
How the robots assist in providing this "kinder, gentler" medicine is a function of what they are. Aesop is a robotic arm capable of precisely inserting an endoscope (a slender optical tube equipped with a camera and light) into a patient's body, enabling the surgeon to remotely view the progress of an operation on a video monitor. Reminiscent of RCA's mascot Nipper, the little white dog who "knew his master's voice," the robot begins its process by recognizing the surgeon's voice (which takes about ten minutes). Aesop then moves only in response to the physician's voiced commands, which are carefully scripted to cover the movements that will be required by the procedure.
Extremely precise, Aesop can move in microns (1/1000th) of an inch, and can be programmed with pre-set "travel" limits that conform to the specific interior anatomic shape of a patient's chest cavity.
Just a year ago, Drs. Colvin and Grossi used Aesop's incredible dexterity to assist in successfully completing a mitral valve repair. Instead of "cracking open" the patient's chest with a 12-16 cm incision to gain access to the heart (the traditional method), the surgeons made only two small incisions-one the width of a pencil, through which Aesop inserted the endoscope based on the surgeons' voice commands, and a second four centimeter incision, through which the doctors manually manipulated their instruments, while focused on the video images Aesop provided.
Commenting on the procedure, Dr. Grossi said, "The thoracic cavity is a new and significant frontier for video-assisted, minimally invasive heart surgery. The precision of the surgical maneuvers required to perform these procedures requires an absolute steady picture, which is what I appreciate most about Aesop. It provides a motionless image of the entire operative field at ten to 15 times magnification, a significant increase over standard surgical loupes [magnifying glasses], which only provide three to four times magnification."
In accordance with Dr. Grossi, Dr. Alan Menkis, a professor of cardiac surgery at the University of Western Ontario and a cardiac surgeon at the London Health Sciences Centre in London, Ontario, says Aesop offers surgeons a revolutionary way to repair heart defects and, indeed, any problem requiring fine micro-surgical repair. Like the NYU doctors, he is enthused by the faster patient recovery times that robot-assisted, minimally invasive surgical procedures can provide. In March of this year, Dr. Menkis performed the first Aesop-assisted mitral valve repair in Canada on John Reinhardt, a 47 year-old bookkeeper in Strathroy, Ontario. Reinhardt was so weak and short of breath from his heart problem that he was deemed unable to tolerate open-heart surgery and was given a ten percent chance of survival unless he received a transplant. He went home five days after Aesop-assisted surgery and later marvelled to Toronto Star newspaper reporters at how quickly he recovered and how small his incisions were. "I'm just amazed they were able to do this through such a small hole," he said.
"In traditional mitral valve surgery," said Dr. Menkis, "where the entire chest is opened, patients usually require a six to 12 week recovery time before doing any significant lifting or exercise. With this new robotic procedure, however, we're seeing an all-around improvement in recovery-an earlier return to work, a shorter ICU stay, shorter ventilatory requirements, and better cosmesis [less scarring of the skin]."
Son of Aesop
Still, if Aesop's assistance seems impressive, Zeus' accomplishments since February of this year might well be considered astounding.
In May, at the 80th Annual Meeting of the American Association of Thoracic Surgery, Dr. Colvin, who is Chief of Cardiothoracic Surgery at NYU, and Dr. Grossi, the institution's Director of Cardiac Surgical Research, reported successful completion of a minimally invasive mitral valve repair on a 50 year-old male as part of a United States Food and Drug Administration-approved, Investigational Device Exemption Phase I clinical study.
Using Zeus to assist this time, Drs. Colvin and Grossi again performed the minimally invasive procedure through a mini-thoracotomy (a four centimeter incision in the chest). Never actually touching the patient, the surgeons were comfortably seated at a console about ten feet away from the operating table during the entire procedure.
As with Aesop, the surgeons noted the typical patient pain and trauma associated with conventional valve repair was avoided. The patient reported little pain the evening after surgery, was mobile and comfortable, and was discharged from the hospital in a few days.
In this procedure, what differed significantly from the Aesop procedure was the role Zeus played. Unlike one-armed Aesop, who acts as the eyes of surgeons during operations, Zeus used its three arms to become the surgeons' eyes and hands. Seated at a workstation and watching a video monitor, the surgeons used simple voice commands to direct the robot's one arm as it positioned the endoscope for an optimum view of the operative site. Once that was accomplished, the operating surgeon grasped a conventional instrument handle in each hand (imagine the ultimate "joystick") and, arms resting on the workstation console, began to perform the movements required to execute the valve repair. Using scaled-down precision, the robot translated each movement through its other two arms, which were equipped with the necessary instruments at the operative site. The surgeons flawlessly performed the delicate operation utilizing remote control.
Explaining the significance of the event, Dr. Grossi said, "Zeus brings us to a new level in visualization and ergonomics for the surgeon. Instead of standing throughout a long [five hours or more] and complex procedure, where my arms are not well supported, it allows me to voice-control the endoscope for greater visualization, while controlling the surgical instruments in real-time from a seat at the workstation. In addition, Zeus' computer interface filters out human hand tremor, providing me with more exact needle placement, which is critical to the success of heart surgery."
Expressing similar optimism, Dr. Colvin commented, "We used to think our eyes and hands limited us. Now we have the technology to go beyond the limits of human performance."
Perhaps the only limit currently holding back the revolution inherent in the new technology is its newness, Dr. Menkis observed. To date, about 300 mitral valve surgeries have been successfully completed, he added, but as the numbers mount, it seems certain the technology will change the way surgery is performed. Indeed, surgeons in various disciplines around the world are busily investigating various applications for Aesop and Zeus. In addition to mitral valve repair and replacement, the robots have already been used to successfully harvest and use mammary arteries for endoscopic coronary artery by-pass grafts, and to repair congenital atrial septal defects ("holes in the heart") in infants. Among other applications, Aesop has also been used by surgeons to remove diseased gall bladders, and as a minimally invasive treatment for prostate cancer. Zeus has also assisted surgeons in endoscopically reconnecting the fallopian tubes of a woman who later gave birth to her first child.
Beyond these unprecedented clinical benefits, Drs. Colvin and Grossi point out that the direct video visualization provided by the robots offers an important opportunity for elite surgeons around the world to teach the next generation of surgeons-via both closed circuit TV at their local institution, and globally, via satellite teleconferencing.
Further, while the remote operation of Zeus from a workstation already provides surgeons with the means to perform procedures on the outside of a "super-sterile" operating room, thereby eliminating the possibility of accidentally infecting a severely ill patient, it also has the potential of allowing elite surgeons to one day operate over great distances- perhaps by voice commands alone. In fact, Computer Motion spokesmen confirm the company is actively developing this capability, convinced that it will be well received by countries like Canada and Australia, where great distances and a relatively sparse population often make it difficult and costly to deliver healthcare.
Ironically, Computer Motion's founder began his career in robotic engineering by building remote control devices for NASA as part of the United States space program. Gradually, however, Dr. Wang's interests drew him away from the high frontier of outer space to working with physicians such as Drs. Colvin, Grossi, and Menkis, who practice medicine in the inner space of the human body.
In what could well turn out to be the ultimate convergence of all, a descendant of Zeus may one day take voice commands via satellite from a student Dr. Colvin is currently teaching, as it performs heart surgery on an astronaut posted at a research station on the moon.