A Warmer Kind of Cooler
More than 2,400 hearts were transplanted in the U.S. last year, most of them packed on ice in an old-fashioned picnic cooler. But there are drawbacks to this form of transportation. Once a heart is disconnected from its blood supply, damage occurs as cells are deprived of oxygen and nutrients. The more time passes, the more damage takes place. Cooling the organ helps, but after about six to eight hours on ice, a heart is no longer suitable for transplantation. As a result, a donor heart in Los Angeles, for example, cannot be used to save a matched patient in Miami.
In addition, surgeons only have time to use factors such as blood type, weight, height, and gender to pair up donors and recipients. Running more sophisticated tests, like those done for kidney transplants, is not an option because the heart will not tolerate the delay. Having time to test for proteins that mount an immune response, for instance, could improve outcomes for transplant patients.
The Heart Transplant Program team at the Cedars-Sinai Heart Institute—whose surgeons perform more heart transplants every year than any other U.S. hospital—is testing an exciting new way to transport donor hearts. From the outside, it looks like an ordinary gray-and-white cooler on wheels: 40 inches tall, 30 inches wide, and 20 inches deep, it weighs less than 100 pounds and fits comfortably in the trunk of an SUV. But inside is a living human heart. Instead of using ice, the TransMedics Organ Care System keeps the organ warm and beating. It simulates the conditions of the human body and allows the organ to function normally. This so-called living organ transplant lengthens the amount of time that a heart is viable for transplant up to 12 hours. Inside the unit, the heart is revived to a beating state and kept warm and sterile, as nutrient-rich blood is delivered through a pump.
By increasing the number of transplantable organs and decreasing the risk of post-transplant complications, this technology could potentially save a great number of lives.