What are the barriers to wider use of organ perfusion?

Q. Where is perfusion having the most impact right now in organ transplantation?

We’re seeing a steady increase in the number of organs being perfused. In 2022, more than 1,100 transplanted donor livers, hearts and lungs were perfused. Between 2018 and 2022, there was an almost five-fold increase in perfused livers transplanted, from fewer than 100 to nearly 500.

Perhaps the most important recent development is perfusion for DCD (donation after circulatory death) heart transplantation. Because the heart is particularly vulnerable to warm ischemic injury, increasing the number of successful DCD heart transplants was really dependent on perfusion technologies. A third of all donors are DCD donors, and potentially a significant number could be heart donors; one study estimated that widespread adoption of DCD heart transplant could lead to 300 more adult heart transplants annually.  UNOS data show that the number of DCD hearts perfused and transplanted has gone from 0 in 2018 to 199 in 2022.

Q. Are there other significant new developments?

In addition to ex-vivo machine perfusion, normothermic regional perfusion (NRP) for recovery of organs from DCD donors is now spreading fairly widely, and is also helping to increase the number of DCD hearts available for transplant. (See Normothermic Regional Perfusion: A reading list.) With NRP, cardiopulmonary bypass or ECMO is used to restore circulation and enable perfusion of DCD organs prior to recovery. Because these technologies are already in use in most ICUs, there is no new technology to acquire or learn to use, as there is with ex-vivo machines. Also with NRP, separate perfusion devices for each organ aren’t needed, as abdominal and thoracic organs can be perfused before recovery with this process.

Q. What barriers remain to greater use of perfusion?

At the present time cost remains the most significant limiting factor for either type of perfusion. It’s expensive, and questions have yet to be resolved about when it is most appropriate to use perfusion,  who pays for it, and how those costs are reimbursed.  Whether cost will limit the use of perfusion to larger and better-resourced transplant centers or OPOs remains to be seen.

Implementation of these technologies is also logistically complex.   It takes time and effort for new technologies and procedures like these to be widely incorporated.

Finally, more data are needed to firmly determine whether perfusion leads to better patient outcomes. Research so far indicates generally equal outcomes when compared with non-perfused organs.  Despite these questions perfusion is enabling increased use of expanded criteria and DCD organs, including those that previously might not have been considered viable for transplant.