The New Organ Care System, or ‘heart in a box’, is a new heart-storage system that keeps hearts warm and beating while they are being transferred from a donor to a new patient, no longer will they require to be packed on ice to be preserved for transplantation.
The ground breaking system designed by Transmedics consists of a transportable cart that keeps the heart at the appropriate temperature and humidity while still supplying it with oxygen, blood and nutrients. These are fed through tubing clamped to the heart to help it continue to beat. Currently, “heart in a box” is too expensive to be distributed widely as its a whopping $250,000 a piece and is still in the testing phase.
In the past the pool of possible donors was rather limited since hearts were taken from brain-dead individuals whose bodies were still healthy. But the “heart in a box” can reanimate a heart that has stopped beating in a body that has undergone “circulatory death,” where the heart itself is no longer functioning, not just the brain, and so the device allows surgeons to take hearts from donors that would not have been eligible in the past.
Without such help, surgeons consider hearts from dead donors too damaged to use. “The device is vital. The heart gets an absolutely essential infusion of blood to restore its energy,” says Stephen Large, a surgeon at Papworth Hospital in the United Kingdom, which has used the system as part of eight heart transplants.
“In the short term they’ll open the field,” commented Korkut Uygun, a transplant surgeon from Massachusetts General Hospital, to the Technology Review. Uygun thinks that one day we’ll have the technology to restore other organs, such as livers, up to an hour after they have undergone circulatory death, not minutes.
Its still early days, but so far there are 15 cases of the “heart in a box” successfully reanimating a heart from a donor after they’ve died.
Typically, an organ is cooled to about 4°C (39°F) to slow down the tissue’s metabolic rate and the rate of degenerative processes. But this system could increase the number of hearts that are transported, overcoming issues such as the time limit heart porters have when transporting a chilled heart. Other vital organs could soon be trialled for example lungs, only last three to six hours on ice – whereas the Transmedics device preserves lungs for 24 hours without needing to cool the organ down.
There is no way to test the function around a cooled organ, as there is no blood flow so it is susceptible to damage. This is especially critical for a patient about to undergo the invasive surgery to receive it, and the months of adapting to the new organ afterwards. Now, a team near Cambridge has taken radical steps to test how the heart functions. Using Transmedics’ device, the team claims to have restarted hearts while still inside dead donors. The doctors can then observe the blood flow to vital organs, before clamping and removing the heart five minutes later. These results are unpublished.
With technology keeping organs alive outside the body, even to save lives, its going to raise some challenging moral.
“How can you say it’s irreversible, when the circulatory function is restored in a different body? We tend to overlook that because we want to transplant these organs,” mused Robert Truog, a medical ethicist from Harvard University, to MIT Technology Review. “My argument is that they are not dead, but also that it doesn’t matter” provided that the family has consented to the procedure. “The question is whether they are being harmed, and I would say they are not.”