New device revives transplant hearts after death

Posted on 4 Nov 2015 by Aiden Burgess

Device saves lives but also raises ethical questions.

The future of organ donation has been changed forever thanks to a new device, aptly named 'Heart in a Box', that allows a heart from a deceased person to resume beating.

Transplant surgeons have started using the ‘Heart in a Box’ device, which allows them to ‘reanimate’ hearts from people who have recently died and use the organs to save others.

The device is a wheeled cart with an oxygen supply, a sterile chamber, and tubing to clamp onto a donor heart and keep it fed with blood and nutrients.

The device stimulates the conditions of the human body as it pumps oxygenated blood inside the heart so it can continue to function as it would inside a living person.

Surgeons in the UK and Australia have used the system in at least 15 cases to successfully transplant hearts removed from patients after they’ve died.

The heart in a box is part of a wider shift away from shipping organs cold to keeping them warm and functioning.

By keeping a donor heart beating en route to transplantation, rather than sitting in a cooler full of ice, the device allows the heart to arrive in better shape.

The device also allows surgeons to assess whether the donor heart is suitable for transplantation, as it’s harder to assess a non-beating heart which can cause mistakes to be made about suitability.

The system also increases the time the heart can be maintained outside the body to at least eight hours, as opposed to the maximum of three to four hours on ice.

According to doctors, the $250,000 system could expand the number of donated hearts by between 15% to 30%, saving the lives of more people who would otherwise die from heart failure.

Heart in a Box developed by TransMedics

TransMedics Heart in a Box device in action
The TransMedics Heart in a Box device in action.

The groundbreaking Organ Care System (OCS) has been developed by US-based TransMedics, the world’s leader in portable ex-vivo machine perfusion and assessment of donor organs for transplantation.

The OCS Heart PROCEED II was trialled by TransMedics and met its success criteria for both the primary effectiveness and safety endpoints by demonstrating that the OCS is as safe and effective as the current standard of care (SOC) in preserving standard donor hearts for transplantation.

The data from the trial also demonstrated that circulating lactate level of the OCS Heart perfusion could be a useful parameter to evaluate donor hearts status ex-vivo.

The trial’s principal investigator and the surgical director of UCLA’s heart and lung transplantation program, Dr. Abbas Ardehali, said the OCS Heart platform was a significant advancement in the field of organ donation.

“Donor organ perfusion is a significant advance in thoracic transplantation and offers an opportunity to improve the quality of the organ, increase the supply, and potentially enhance the donor organ,” he said.

“The completion of this trial and the publication of the results in the Lancet Journal is an important foundational step in bringing beating heart transplants into our routine clinical practice in the US.”

The ethics of death

Despite the advancement it brings to organ donation, the OCS Heart system also raises ethical questions.

Donors whose hearts have been facilitated in the new device have included victims of car accidents and failed suicide attempts.

The dilemma that arises is, if their hearts do stop, how long should surgeons wait before retrieving the vital organ.

Medical ethicist at Harvard University, Robert Truog, addresses this dilemma by questioning if these types of donors are really dead, given that their hearts can be restarted.

“How can you say it’s irreversible, when the circulatory function is restored in a different body?” he asked.

“We tend to overlook that because we want to transplant these organs.

“My argument is that they are not dead, but also that it doesn’t matter, so long as they and family members have given consent.

“They are dying and it’s permissible to use their organs, the question is whether they are being harmed, and I would say they are not.”

An incident which can be seen as a microcosm of this ethical dilemma occurred in 2008, when Colorado surgeons took hearts from brain-damaged newborns after waiting only 75 seconds.