What a gorgeous piece of machinery the human body is! Without even a conscious thought we do things like wake up each day, breathe and swallow—and that’s just the basic stuff. We also do an infinite variety of more complicated tasks, like changing light bulbs and baby diapers, climbing stairs and getting in and out of the car, gardening, playing the violin or competing in triathlons. It’s all made possible by a collection of complex bodily systems—containing a multitude of smaller parts perfectly designed to perform highly specific functions—that work in synchrony.
Surgery has been called a blend of art and science but it may be time to add an entirely new discipline to that description—engineering. Surgeons today are performing not only organ transplants and hip and knee replacements, but wondrous feats like face and hand transplants, and cochlear transplants that enable the deaf to hear again. Biomedical engineers have even developed a prosthetic arm that can be controlled by thought!
Here we travel to some of the state’s hospitals to look at the science and technology involved in developing “replacement parts” for the human body right here in Connecticut.
Engineering tissue to make a new blood vessel
In a 14-hour surgical procedure involving 50 doctors, nurses and other medical professionals who’d practiced their tasks with stopwatches for months beforehand, a Connecticut toddler born with a life-threatening heart defect received this country’s first-ever “tissue-engineered vascular graft” at Yale-New Haven Hospital. Cells taken from her bone marrow were attached to a biodegradable scaffold that will grow into a new blood vessel that will function in place of the one she was born without.
This operation, which took place last August and was led by Drs. Toshi Shinoka and Gary Kopf, was the first in an FDA-approved clinical trial that is evaluating the technique as a treatment for children born with single ventricular congenital heart disease. The mortality rate for infants born with this birth defect, commonly called “blue baby syndrome” because the lack of oxygen in the blood gives the child a bluish tint, is 70 percent in the first year of life if left untreated.
According to Christopher Breuer, M.D., a pediatric surgeon at Yale-New Haven Hospital who conducted the research leading to the surgery, this is groundbreaking because what gets produced is a blood vessel that will grow with the child since it was made with cells from her own body. It’s a major improvement over the procedure that employs a blood vessel made of a synthetic material, a procedure that has to be repeated periodically as the child outgrows the vascular graft.
Breuer, who initially wanted to be a pediatrician, was drawn to the nascent field of tissue engineering because, he says, it brought together medicine and science in a way that he found rewarding and exciting. Trained at Harvard, he joined the tissue-engineering program at Yale because of its singular focus on blood vessels. “It was incredibly enabling to be in a program where all the resources were concentrated in one area,” he says.
With the first young patient doing very well six months after her operation, Breuer anticipates performing this surgery on several more pediatric patients in the months to come, and envisions a time in the not-too-distant future when adults, too, will receive these vascular grafts in cardiovascular surgeries.
Yale “provides an incredible environment to allow us to do this stuff,” says Breuer. He also credits the Food & Drug Administration and the National Institutes of Health (“some people find their approval process long and arduous but I think it is time well spent improving the safety of the operation”) and the Doris Duke Charitable Foundation, which continues to fund this important research.
Wrist and knuckle replacements
The human hand is an amazingly complicated arrangement of 27 bones and numerous muscles, tendons and ligaments that enable us to move our fingers, thumbs and wrists up, down and around to write, pick up small objects, button clothing and perform a host of other complex tasks. Most of us never think about any of this—until, that is, those parts don’t work so well. Where hand surgeons used to be limited in what they could offer such patients, there are now about 30 surgeons around the country who can replace faulty wrist and/or knuckle joints with devices that allow them to resume full function.
“In the past, the options for arthritic wrists and knuckles have been to perform a fusion, which is when we keep the wrist in one position, or to do nothing at all,” explains hand surgeon Sep Sajjad, M.D., of the New England Hand Center, who operates at Lawrence & Memorial Hospital in New London. “Now we have a technology that allows us to take out the bad bones and replace them with a prosthetic wrist or knuckle that moves in various directions.” Sajjad says that he has performed five wrist replacements in the past year, along with 35 knuckle replacements in 15 patients, replacing several joints at a time in some.
He learned to do these complex surgeries under the tutelage of J. Grant Thomson, M.D., director of the hand surgery program at the Yale School of Medicine. Most wrist and knuckle replacement patients are in their 50s or older, suffering either rheumatoid arthritis or osteoarthritis that makes it difficult to use their hands. Wrist replacements have been available for only about 10 years, Sajjad says, pointing out that they offer great mobility—a tremendous advantage over fusion, which “can solve the pain of hand arthritis but results in a joint that doesn’t move normally.”
The new replacement parts allow patients to move their fingers and wrists quite normally, according to Sajjad (though weight-lifting and impact sports, like tennis, aren’t an option after the procedure). The joint replacements look natural too, which is a major improvement since arthritic knuckles tend to become swollen and misshapen. Sajjad says that his patients—who have included a police officer (who can now hold his gun securely), a pianist (who now hits every note) and even a surgeon (now operating with confidence)—have been thrilled with their new joints.
Liver transplants from the living and deceased
Organ donations save lives but, of course, it’s a complicated equation. Hartford Hospital’s Transplant Program has been performing heart, kidney and liver transplants for decades. Most of these are made possible because someone’s life has ended abruptly and prematurely. Donating a loved one’s organs, though an appalling choice to have to make at such a time, can be a way to find grace in such a loss. According to Patricia Sheiner, M.D., director of Hartford’s transplant program, the need for organ donations remains high. “The number of patients waiting for transplants increases each year but the number of donors remains stagnant,” she says. “It’s difficult to watch a patient deteriorate, knowing that a transplant could save his or her life.”
There are some organ transplants that can be done from a living person, however—live-donor kidney transplants are routine and live liver transplants are also being done now. Hartford Hospital recently opened a Comprehensive Liver Center, which offers what Sheiner characterizes as the “full spectrum of treatment for liver disease,” including liver transplants. (Eventually the hospital will perform live-donor liver transplants as well, which involve donation of a portion of a living person’s liver to a patient who needs a new organ. Both the donor and recipient livers grow back to normal size within about two months.)
There’s been tremendous growth in the need for liver transplants for several reasons, Sheiner explains—one being hepatitis C, which became widespread in the 1970s and 1980s and has, in many patients, progressed to the point where the liver no longer functions. An increasing number of patients also require transplants because of damage wrought by poor lifestyle habits—“nonalcoholic fatty liver disease,” due to obesity, can be deeply destructive and irreversible. Alcohol abuse that leads to cirrhosis is another cause. There are also many non-lifestyle-related liver diseases that can result in the need for a transplant.
The Comprehensive Liver Center provides all the care a person with liver disease may require, including medical therapies (such as a new drug regimen that treats hepatitis C), a dedicated liver-cancer clinic composed of physicians representing a number of specialties, help with financial and psychological issues and follow-up monitoring and care. “Liver transplant is a fairly lengthy process,” says Sheiner. “Prospective patients receive lots of teaching and education and meet often with the center’s transplant coordinator, as well as with social workers and surgeons.” Patients waiting for a liver from a suitable donor to become available can spend months in the hospital (Hartford now has a special unit for them), with some running out of time before the right donor can be found. That’s why a live donation can be such a life-saver.
Sheiner, who came to Hartford from Westchester Medical Center in Valhalla, N.Y., last fall, estimates that she has done about 850 liver transplants in the course of her career. “A liver transplant is one of the most technically challenging operations a surgeon can do,” she explains, adding that “it’s amazing to take out a diseased liver, put in a new one and then within three days, the patient looks like a different person.” Her favorite part is staying closely connected to her patients long after the surgery is done—a girl whose liver she transplanted years ago recently sent her one of the three gold medals she had earned as a swimmer in the “Transplant Olympics.” “It’s a little bit like being the family doctor for the rest of a patient’s life,” she says.
Knee and hip replacements have become almost routine—now shoulder replacements are becoming more commonplace. According to Seth Miller, M.D., an orthopedic surgeon with Orthopaedic & Neurosurgery Specialists in Greenwich who operates at Greenwich Hospital, the first shoulder replacement was done in the 1950s but it was not until fairly recently that the materials and the technique were refined to the point that the surgery could be widely available.
Shoulder replacements are most often performed on people with arthritis that has progressed to the point where any use of the arm is painful, says Miller. “When there’s no cartilage left, you have abnormal surfaces of the bone rubbing on bone, which makes the simplest acts painful—even bathing, dressing and eating,” he explains. “People with this condition can’t even sleep well, because any time they move or roll over or lie on the affected side, the pain wakes them up.”
The shoulder-replacement procedure and the materials from which the replacements are crafted are now in what Miller calls the “fourth generation.” He goes on to explain that “we not only use better materials but the joints themselves are available in a far more extensive selection of sizes and shapes. Patients are fitted in a customized way that makes the replacement joint as similar to the original as possible.”
Miller says that more patients are experiencing overuse injuries related to sports, so he expects the number of shoulder replacements to continue to grow. “Kids are getting involved in sports at much younger ages and that, unfortunately, sometimes lands them in my office with various types of overuse problems, like tendonitis and bursitis,” he says. “I’ve seen patients as young as 8 or 9 who’ve injured their shoulders swimming or playing squash, tennis or baseball. We also see other sorts of injuries as people start to get older, such as rotator-cuff injuries and shoulder instability, where the joint slides in and out of the socket, which can happen even in the 20s.”
Miller has performed more than a thousand shoulder replacements. He says that another reason for the increased numbers is a new procedure that makes the operation appropriate for patients with both severe shoulder arthritis and torn rotator cuffs. “A new type of shoulder replacement procedure changes the mechanics of the shoulder. By reversing the configuration of the ball and socket in the joint, the deltoid muscle becomes the primary mover of the shoulder,” he explains, adding that the approach has been used successfully in Europe for a long time but in the U.S. for less than a decade. Miller was the first Connecticut surgeon to perform this type of shoulder replacement.
Artery repair and replacement
An aortic aneurysm can—and usually does—kill patients quickly and without warning since there are few, if any, warning signs. “When an aneurysm ruptures, the chances for survival are small,” says Alan M. Dietzek, M.D., chief of vascular and endovascular surgery at Western Connecticut Health Network’s Danbury Hospital and an associate professor of surgery at the University of Vermont College of Medicine. He notes that at present about 15,000 people in this country die each year from aortic aneurysms.
The term aneurysm refers to a ballooning of the aorta (the body’s main artery leading from the heart) that puts it in danger of rupture at any moment. Previously, repair of aortic aneurysms required major open abdominal and/or chest surgery, but now there is a minimally invasive technique that allows doctors to repair a bulging aorta nonsurgically with a Teflon-lined stent that stays in place and becomes a sort of permanent patch. Called a Thoracic Endovascular Aortic Graft or TEVAR (when the damaged aorta is located in the chest) or an Endovascular Aortic Graft or EVAR (for aneurysms in the abdomen), the device and procedure are, according to Dietzek, a “remarkable advancement” that significantly lowers the complication and mortality rates associated with open surgery for this disease. Dietzek is among the country’s most experienced EVAR surgeons.
This new procedure also offers a relatively simple solution for patients who previously were deemed too much of a risk to put through the open surgery that was otherwise their only option. “Most aortic aneurysms today are discovered incidentally by testing performed for other reasons,” says Dietzek. He urges patients at risk (those with a family history of aortic aneurysm, those with poorly controlled hypertension and/or smokers) to ask their doctor whether they need a thorough exam and maybe even an ultrasound of the abdomen.
Small aneurysms are not usually repaired but rather monitored; if they grow, repair may become necessary. With this new minimally invasive approach, most patients are able to return home after just a day or two in the hospital, Dietzek says, adding that yet another improvement—an all-percutaneous approach—now enables doctors to patch aneurysms without making any incisions at all. “We’ve been doing this at our hospital and recovery is even faster,” he says.