New Method Saves Donated Organs
Doctors Develop a High-Tech System
to Salvage Donated Organs
By Alexa Pozniak
B O S T O N, Dec. 7
Eight hundred Americans die each year as they desperately wait for a new heart. But now doctors have developed a way to preserve donor hearts that may save more lives by increasing the health and expanding the pool of donated organs.
Using a portable organ preservation system, or POPS, researchers at the University of Pittsburgh recently kept a human heart beating for nearly 12 hours before disconnecting the system to perform further testing.
Doctors are hopeful POPS will change the face of transplantation. "This is a breakthrough, and an extremely novel approach that could change the whole way we do transplantation," says Dr. Robert L. Kormos, director of thoracic transplantation and the artificial heart program at the University of Pittsburgh. Time will tell, we just have to apply it in patients and see what we can learn."
In addition to hearts, the device has also shown promise with kidneys, and researchers are hoping other organs will respond the same way.
How POPS Works
When an organ donor dies, a variety of toxic substances and hormones are released into the blood stream, often placing severe stress on the heart, causing the arteries to become inflamed and damaging muscle tissue, especially in hearts that are old or sick.
Using current methods, the heart is taken out of the body and placed in a cooler, packed with ice and preservation solutions that sustain it for up to six hours. But even that allows damage to set in to the organ.
The new POPS approach works to reduce that damage by mimicking the actions of a healthy human body, acting as an artificial circulatory system, lung, and even kidney and liver.
The machine provides continuous blood flow to keep the heart pumping, provides fresh oxygen, filters out poisonous carbon dioxide and toxins, and provides the heart with important nutrients and chemicals.
Possibilities, But Also Problems
Although Pittsburgh researchers have not yet implanted a POPS-protected heart into a donor, and the system is still fairly new, experts are optimistic about its potential.
"A longer preservation time would allow us to share organs across greater distances, and more patients would benefit from life-saving transplants," says Kormos.
Adds Dr. Kenneth R. McCurry, director of lung and heart-lung transplantation at the University of Pittsburgh: "POPS might allow us to use hearts and lungs from nonheart-beating donors. We'd essentially be able to resuscitate these organs, then transplant them."
But Dr. Frank Pagani, director of the heart transplant program at the University of Michican, says the idea of using a device like the POPS has been explored for some time and there are problems.
"Some of the difficulties related to maintaining sterility, the perfusion devices were cumbersome to use and transport, and organs did demonstrate some degree of swelling and dysfunction on these devices," Pagani explains. "If this device is successful in overcoming some of these hurdles, then it would have an impact on how we currently practice harvesting organs. It may improve the supply of organs to some extent, but I do not think the supply of organs could be greatly increased."
Researching Pre-Transplant Treatment
Doctors are also exploring the possibility of using the POPS device to treat the heart before it is placed inside the recipient, which could increase a transplant's success rate and perhaps even boost the heart's health.
One idea is to send certain drugs through the system that would allow the heart to become immunologically prepared for the transplant. Another, adds Kormos, is to line the heart with genes to make it respond differently to the recipient.
"The lining of the blood vessels are extremely sensitive to any insult, such as viruses, or injuries that occur in a patient with high cholesterol, or the inflammation that occurs after taking the heart out of a brain-dead individual," he says. If the lining could be made genetically resistant to that injury down the road, or the response of the artery to that injury could be modified, that could prevent coronary disease, Kormos explains.
Currently, up to 50 percent of the transplanted hearts develop coronary artery disease within five years, and by 10 years 80 percent are affected by the condition. Experts say this is what eventually kills the recipients.