Damaged lungs from organ donors could soon be made viable for transplantation owing to a new technique.
Clinicians and researchers at Newcastle University and NHS Foundation Trust are now working with device manufacturer Vivoline Medical to conduct a trial in patients.
‘Out of all the organs in the body the lungs are the most sensitive,’ said Prof Andrew Fisher of Newcastle. ‘Due to the events that happen leading up to the donor’s death — a major accident, or head injury — the lung picks up on that inflammatory environment very quickly and you flood alveoli spaces so that the gas-exchange capacity is not as good as it should be.’
Only one in five of the potential donor lungs available in the UK are used in lung transplants, the rest are turned down as they are in too poor a condition to safely transplant. Close to a third of those waiting for a lung transplant at any one time will never be matched with a donor organ, meaning that many patients who would benefit from a lung transplant will die before suitable donor lungs are identified.
Currently, donated lungs can be stored for transportation for a maximum of 10 hours in an ice slurry box at 4ºC. Generally speaking, the longer this ‘ischemic time’, the higher the risk of poor functionality.
In effect, the new technique, called ex vivo lung perfusion (EVLP) cleans the lungs then attaches them to a modified heart-lung bypass machine that pumps a specialised nutrient liquid through, while at the same time providing the lungs with oxygen via a breathing machine.
It also provides an objective assessment tool that can measure the gas-exchange efficiency and aid decision making.
‘A lot of the assessment that’s done on a donor organ is quite subjective — how does the lung look, is it inflated properly, are there any signs of external damage — and the decision has to be made in an instant,’ said Prof Fisher.
‘What the ex vivo lung perfusion circuit allows us to do is assessment on an hourly basis and the minute it crosses the threshold then you can say: “Right we’re now confident that this lung is good enough to transplant and we’ll go ahead”.’
A National Institute for Heath Research Study will now assess survival in recipient patients the first 12 months after transplant with EVLP-improved lungs comparable to that achieved with standard donor lungs.
Prof Fisher hopes in the future that the platform could be used to deliver therapies and actually improve functionality of non-damaged lungs and decrease the chances of rejection.