Once a human heart becomes available for transplant, the race is on. A team of cardiac specialists immediately leaves the hospital by the fastest means possible to get to the donor who is about to die. Once the heart is retrieved, the clock is ticking. The excised heart, placed in a plastic bag and packed in a store-bought picnic cooler filled with pounds of ice, has to be transplanted within 240 minutes to achieve the best results.
A human heart in a picnic cooler? It’s the way it’s been done for 30 years. When the flow of warm oxygenated blood to the heart is stopped and the heart is removed and placed in a cooler, the heart begins to slowly decay, even when packed in ice, which is why there is a four-hour window for replacement.
On any given day, about 4,000 people are waiting for a heart transplant in the United States. “Transporting a donor heart is a very crude process, but efficient,” says Tomislav Mihaljevic, M.D., Staff Cardiac Surgeon at the Cleveland Clinic, and a member of the heart transplant team. “The picnic cooler has worked very well for many years and benefited thousands of patients. Granted, it’s not the optimal way to transport a heart.”
Now, with the world’s first warm blood perfusion system approved for use in Europe, and undergoing its pivotal multicenter testing phase in the United States, there is finally a better way to transport a variety of living organs, including the heart.
“The device is actually a portable miniature heart/lung machine,” says Dr. Mihaljevic of the warm organ perfusion equipment. “When the heart is harvested, we take a liter of blood from the donor and put it into the device, which recreates conditions found inside a healthy body. The heart is then placed into the device and the warm blood is slowly pumped through it. The heart naturally starts beating,” And the heart keeps beating, right up until the time it is transplanted. In tests, hearts have kept beating for upwards of 12 hours in the warm organ perfusion device, greatly expanding the four-hour transplant window.
“We have transplanted three hearts with this new technology,” says Dr. Mihaljevic, “and achieved excellent results. Heart function was measurably better. The patients recovered very quickly. I am very satisfied by the results.”
The warm organ perfusion device is a game changing innovation, says Dr. Mihaljevic. “Once it receives FDA approval, the technology will impact not only the way that we do heart transplants, but the way that we do other solid organ transplants with the kidney, liver, and lung.”
Where Are They Now
By slowly pumping warm blood through organs and keeping them in a functioning state, this game-changing innovation offers a much better way to transport a variety of living organs-such as hearts-for transplantation. By extending the time that a donor organ can be maintained outside of the body, this technology not only provides better preservation of an organ's function prior to transplant, but should also help to ameliorate the effects of the worldwide donor organ shortage, which remains one of the biggest problems in this field.
The world's first warm blood perfusion system for the heart has been approved for use in Europe and one for lungs has been approved in the US. One hospital has successfully completed 20 sets of lung transplants using warm perfusion, increasing their yearly total of lung transplants to 52, compared to only 30 transplants the year prior. The goal is to continue to develop the technology with the aim of bringing it to market in the coming future. As of 2017, additional applications for warm blood perfusion systems are being explored in clinical trials involving heart and liver transplants.