Human hearts from the potential donors that had been deemed unsuitable for transplantation could get a second chance to save a life, say a team of researchers at the University of Sunderland in collaboration with Newcastle University, both in the UK. The scientists are working to restart hearts and develop tests to prove they are still viable, which could potentially increase the use of more declined donor hearts and help to reduce transplant waiting lists.
Dr. Noel Carter, senior lecturer in molecular biology at the University of Sunderland’s Faculty of Applied Sciences, said: “We have demonstrated enough evidence in our results from restarting pigs’ hearts after several hours of being clinically dead, to be able to begin clinical testing on human hearts that are considered too marginal to be used for transplant or as a source of heart valves.”
The researchers developed a novel circulatory equipment and defibrillators to pump warm, oxygenated blood through the hearts and used dialysis to filter out unwanted products from the circuit thereby restoring the heart’s metabolic activity.
They said that other organ transplants, such as the liver and kidney, have managed to increase the use of more marginal and older donors. This is often not possible for the heart due to heart disease and the effect of certain drugs on the heart toward the end of life. As a result patients with cardiac failure are increasingly using mechanical devices to support their own hearts as a definitive treatment rather than them being a bridge until a heart transplant becomes available.
This latest research is in addition to previous work by the same Sunderland research group hoping to expand the donor pool by looking at non-heartbeating donors. These are cases where patients have suffered a heart attack either in intensive care, Accident & Emergency, or outside the hospital environment, and there has been an extended period of time in which the body is warm and there is no oxygen being supplied to the organs.
One strategy is to remove the organs and store them cold to try and minimize metabolic damage. The other option is to take a warm oxygenated approach called ECMO (Extra-Corporeal Membrane Oxygenation) where warm oxygenated blood is put round the organs while waiting for them to be transplanted. This research has led to the development of new medical devices to allow the rapid cooling of the organs, which have been approved by the NHS and have been used in clinical practice.