For over 2000 years, leeches were needlessly applied to treat a multitude of maladies as an adjunct to bloodletting. Since medieval times the leech has been used to cure everything from fever to possession by evil spirits. Now I know leeches may seem a bit outdated in modern medicine, but a 21st century robotic version of these slimy little blood suckers may soon be let loose inside the chests of heart patients. As the April 2007 New Scientist explains, a tiny device known as the Heartlander, brainchild of scientists at Carnegie Mellon University, can slide across the still beating heart of a patient and deliver treatment without the need for open heart surgery.
While the application of these robotic leeches may not be available for human trials just yet, their potential for treating congestive heart failure patients certainly merits our attention, because let’s face it, the thought of leeches mending our broken hearts doesn’t suck.
Now for many of us, the advent of the Heartlander may conjure up images of the miniaturized surgical team in the 1966 film “Fantastic voyage,” in which Donald Pleasance and his fellow mini-adventurers aboard the submarine Proteus are shrunk to microscopic size so they can remove a blood clot from inside a human brain. The reality of procedures such as this is explained in the April 19, 2007 Guardian, which states, “the Heartlander team hopes their creepy-crawly robot will be much less traumatic for both surgeons and patients.” Traditional open-heart surgery, commonly used for bypass, involves surgeons opening up the patient’s chest and pulling back the ribs. Recovering from this operation can take weeks.
However, according to the April 2007 New Scientist, The Heartlander can be inserted using minimally invasive keyhole surgery. Once in place, it will attach itself to the heart and begin inching its way across the outside of the organ, injecting drugs or attaching medical devices. In tests on pigs, the Heartlander has fitted pacemaker leads and injected dye into the heart. The September 16, 2007 Philadelphia Inquirer explains, the 20-milimeter-long robot has two suckers for feet, each pierced with 20 holes connected to a vacuum line, which hold it onto the outside of the heart. By moving its two body segments back and forth relative to one another it can crawl across the heart at up to 18 centimeters per minute. This back and forth movement is generated by pushing and pulling wires that run back to motors outside the patient’s body.
The plan, according to developer Cameron Riviere in the May 7, 2007 Business Week, is to insert the Heartlander through an incision below the ribcage, and pass it through a further incision in the membrane that encloses the heart. Surgeons keep track of the device using X-ray video, or a magnetic tracker, and control its movement via a joystick. “This device is certainly like nothing else I’ve seen,” says Andrew Rankin, a cardiologist at the University of Glasgow in the U.K., April 18, 2007. “Many procedures can be performed by passing instruments into the heart through blood vessels, but it is not possible where damaged or diseased tissue is close to the heart’s surface.” This device could be useful in those cases.
Medical News Today explains on April 25, 2007, the latest research shows that over 308,000 patients underwent coronary artery bypass surgery last year. “Though minimally invasive procedures on a beating heart are sometimes possible, some areas of the heart are out of reach to instruments inserted through keyhole incisions and the limited space in the chest cavity makes operating difficult.” Along with the use of other robotic devices, the Heartlander can reach all parts of the heart’s surface.
Currently, according to the previously cited Philadelphia Inquirer, the use of laparoscopic coronary artery bypass surgery has increased in popularity, so more surgeons are using robotic arms controlled by joysticks, tools that some say make the operation easier. There are fewer occurrences of hand tremors, and with the use of three-dimensional cameras, as Dr. Joseph Woo explains, “it looks like you are sitting inside the heart.” Unlike laparoscopic instruments, small robotic arms have full range of motion and much smaller incisions are required.
Men’s Health Magazine goes on to explain, In April of this year Joseph M. Hendrickson underwent bypass surgery where surgeons used robotic arms to relieve the strain on three of his plaque-choked arteries. While sitting around the fishing hole six weeks later, he proceeded to explain to his two fishing buddies that doctors were able to sew grafts on to his beating heart through an incision no larger than the size of your average fishing lure. “They just couldn’t believe I was out fishing already and in no pain whatsoever,” Hendricks explained. The two men who had also undergone bypass surgery stepped forward to tell him they knew better, each sporting eight-inch scars from where doctors sawed through their chests to get to their hearts.
Through a combination of robotic arms and stents, or small mesh tubes used to prop the blood vessels open, Dr. Francis P. Sutter, explains “we can do these surgeries on very sick patients without putting them on heart and lung machines that have been known to diminish cognitive ability.” Robotic technologies now allow surgeons to sit a few feet from a patient peering through a three-dimensional scope, manipulating the robotic arms like a space-age marionette.
The October 5, 2007 Medical News Today explains, the prototype has not been tested on humans, which will take several years, so it is unlikely to be in general use by heart surgeons before the year 2013. Medical News Today goes on to explain that heart experts have welcomed and praised the idea of the Heartlander. However, they wonder whether in practice it will be as useful as its inventors hope. Many heart procedures require access to the inside of the heart, whereas the Heartlander only accesses the outer surface.
However, with the advent of other robotic techniques, the Heartlander’s potential for aiding in bypass surgeries in the future is very exciting. Dr. Rankin, in the previously cited New Scientist reveals that this device will come into its own for future treatments such as stem cell therapies to encourage regeneration of heart tissue. Medical News Today goes on to explain that injections of adult stem cells into damaged heart tissue significantly improved heart function in patients with severe congestive heart failure. In fact in current trials, patients who have received stem cell injections therapy have seen a 45 percent increase in healthy tissue re-growth, as well as their heart’s improved ability to contract more effectively and restore its blood supply. The only problem is that stem cell therapies must be performed on an open heart to avoid pushing a needle too deeply into a patient’s heart.
This is where the Heartlander has the most potential for revolutionizing heart surgery. By attaching steel robotic hands and three-dimensional cameras to the end of the Heartlander, essentially giving the little leech eyes and arms, the device can move through the surface of the heart, even the difficult to reach areas at the back of the heart, and deliver treatment. The Heartlander has the ability to burn away dead or diseased tissue and inject stem cells in precise locations in the heart without having to rip open the patient’s chest. According to Dr. Riviere in the April 19, 2007 London Daily Mail, this will also alleviate serious complications such as abnormal heart rhythms, and the danger of strokes that are commonly associated with a surgery as dangerous as coronary artery bypass. While the Heartlander may not be able to perform bypass surgery on its own, its potential for creating longer healthier lives by providing much needed follow up therapy in a much less invasive way, is certainly impressive.
You know talking about leeches for this long reminds me of a disturbing scene in my favorite movie “Stand By Me,” you know the one I’m talking about. Now I’m not saying that you should run out and jump into the first swamp you see for improved health, but the next time you encounter one of our little blood sucking friends, and you will, remember to keep an open mind, or at the very least, an open heart.
-Roger
No comments:
Post a Comment