A recent breakthrough could keep an organ alive for 24 hours after donation.
Keeping a donated heart alive for a day or more is a step closer – and could mean fewer people dying while on the transplant waiting list.
A new method was tested on the first patient in August 2017, with a heart kept in a ‘deep sleep’ state for three hours. It will be tested on five more and, if all goes well the storage time will be gradually raised to 24 hours.
And it could potentially be extended to several days, according to Professor Stig Sheen of Lund University, Sweden, who developed the technique.
"We say no to a lot of good hearts," he said. "With the way, we can take hearts from theoretically the whole world. We can get the perfect fit for each patient." The usual way to transport heart involves keeping the organs at 4°C, without an oxygen supply. The upper limit is about four hours.
A recent advance was a device that keeps the heart beating at body temperature, perfused with blood from the donor. US firm TransMedics, who make the device, say hearts can be kept on it from between 7 and 12 hours.
"It has dramatically increased the number of heart transplants we can do," said Mr André Simon, consultant cardiac surgeon at Royal Brompton and Harefield hospitals, which is spearheading its use in the UK.
Professor Steen’s system keeps the heart at 8°C, permeating it with a blood-like fluid containing high levels of potassium that stop it from beating. In this state, the cells are less active than at body temperature and the need for oxygen is slashed.
"It’s like being in a deep sleep," said Professor Sheen.
As a result, the heart can be perfused at a lower rate than when it is beating, which should put less stress on its blood vessels.
The patient who received a heart in this way was a 52-year-old man with heart failure. Stored for three hours, the heart automatically resumed beating once it warmed up inside the man’s body and his blood flushed away the potassium. He is recovering at home.
The TransMedics machine and the Swedish technique have other advantages over storage at 4°C. Hearts are usually taken from people who are brain-dead, so providing the blood-like fluid means the muscles recover.
"When you perfuse the heart with normal concentrations of everything , the heart repairs itself," said Professor Steen.
Source: ‘Hearts that beat the death sentence’, Metro, 12 October 2017, p. 16-17
Consultant cardiothoracic surgeon
Director of heart and lung transplantation