Theme 1 is led by Professor Chris Watson (Cambridge), Professor Andy Fisher (Newcastle), Dr Sarah Hosgood (Cambridge) and Dr Fotios Sampaziotis (Cambridge). It focuses on the use of new perfusion technologies in organ transplantation. The term perfusion means passing blood or another fluid through the blood vessels of an organ.
Traditionally, donor organs like the liver, kidneys, heart and lungs are stored in an ice box before transplantation. This is known as cold storage and it preserves the organ. Cold storage is simple and inexpensive. However, it is not perfect and the organ slowly deteriorates. This can affect how well it works when transplanted.
In organ transplantation, perfusion can be used to see how well an organ is working. It can also repair some of the damage that occurs during cold storage. In addition, perfusion can be used to give treatments to organs to improve how well they work after transplant. As a result, perfusion can increase the number of organs suitable for transplant. It can therefore help to overcome the shortage of donor organs.
Perfusion can be carried out at a cold temperature (hypothermic) or at normal body temperature (normothermic). It can also be carried out before the organs have been removed from the donor (normothermic regional perfusion) or once they have been removed (hypothermic or normothermic machine perfusion).
In normothermic regional perfusion (NRP) oxygenated blood is supplied to the donor’s organs before they are removed. This can help the organs tolerate cold storage better. It also allows organs to be assessed before they are removed from the donor.
Normothermic machine perfusion (NMP) is a technique that is carried out once an organ has been removed from the donor. It involves connecting the organ to a machine before it is transplanted. The organ is perfused with oxygenated blood or a blood-like substance and nutrients at normal body temperature. This revives the organ and repairs some of the damage that occurred during cold storage. It also allows surgeons to check if the organ is suitable for transplantation. During NMP the organ can also be treated with drugs or therapies to improve its quality.
Hypothermic machine perfusion (HMP) is similar to NMP except that perfusion takes place at a low temperature. It can improve organ preservation and allow organs to be stored for longer.
Organ perfusion is a very promising technology but there are lots of questions still to answer.
Our Theme Leads and their teams in Cambridge and Newcastle have internationally recognised expertise in the perfusion of hearts, lungs, livers and kidneys. The main aims of the organ perfusion research being carried out by the BTRU are:
- to identify the best national system for delivering organ perfusion in all transplant centres
- to identify the best conditions to use for perfusion, e.g. the best temperature
- to develop a range of new treatments that can be given to organs before transplantation to improve their quality and increase their lifespan
- to develop a registry (database) with NHS Blood and Transplant (NHSBT) to ensure that data on organ perfusion is collected on a national basis
Patient impact
Development of perfusion technologies will increase the number of organs available. This is because it will be possible to identify more accurately those organs that will function satisfactorily after transplant. This should reduce the number that are declined for transplantation because of doubts over their quality. Further patient benefit will be gained through repairing and treating organs before they are transplanted to improve organ quality and long-term outcome.
The short animation below brings the idea of organ perfusion to life. It was created by illustrator Jess Nash as part of the Cambridge Creative Encounters project.
