Our Harefield Transplant Appeal is raising funds for Organ Care Systems (OCS), which are not currently funded by the NHS. The OCS uses state-of-the-art technology to keep donor hearts beating outside of the human body. Donated organs can come from further away, arrive in better condition and give staff more time to prepare for surgery. So, what happens once a donated heart becomes available?

Incoming call

The transplant team at Harefield Hospital receives a call from one of the recipient transplant co-ordinators to say that an organ donor has sadly passed away and is registered to donate their heart or lungs, which has been allocated to a patient at Harefield.

The on-call retrieval team, consisting of surgeons, a perfusionist (like Louise, pictured left), a scrub nurse and an operating department practitioner, is given one hour before they must be ready to leave for the donor hospital, where they will travel with the OCS. This can be at any time of day or night!


All the retrieval teams, from different hospitals, arrive at the donor site. Once all teams are present, a handover takes place, led by a specialist nurse in organ donation.

The preparation can take from two to four hours. The removal itself takes approximately 20 minutes. Harefield’s transplant surgeons then connect the donor heart to the OCS, which has been set up by a specialist perfusionist using donated blood. The heart is then given a shock of electricity to restart it.

Return journey

Once the heart is in the OCS, it is closely monitored for the duration of the return journey, remaining in a warm and beating state until ready to be disconnected for transplantation at Harefield. The OCS delivers oxygen and warm blood to keep the heart alive. This means the transplant team can travel further to collect the donated organs, compared the traditional ice storage method.

Life-saving surgery

It can take 30 minutes to five hours to prepare the transplant patient for surgery, depending on how many previous surgeries they have had. This all happens while the retrieval team is at the donor site or when they are on their way back – depending on the length of the return journey. When back at Harefield, the OCS remains in theatre, until the consultant transplanting surgeon is ready for the heart to be transplanted.

New life

During the surgery, the recipient is connected to a bypass machine, run by a perfusionist, which takes over the function of the heart until it has fully stabilised in the recipient.

The portable part of the OCS – the Heart Console, cannot be reused. It is this part of the machine that our Harefield Transplant Appeal will fund.

But we need your help. To read more about this life-changing appeal, or to fundraise or donate, click here