Perfused Liver Utilisation Study (PLUS) v1.0 13/08/2021
Research type
Research Study
Full title
Utilisation of normothermic machine preservation in extended criteria livers - a national threshold-crossing study
IRAS ID
283200
Contact name
Trials & Research Governance
Contact email
Sponsor organisation
University of Oxford / Research Governance, Ethics & Assurance Team (RGEA
ISRCTN Number
ISRCTN11552402
Duration of Study in the UK
4 years, 11 months, 30 days
Research summary
The supply of suitable livers for transplantation is lower than the number of patients who could benefit. More than 10% of patients on the waiting list die before receiving a transplant. Less than 2/3 of deceased donors in the UK result in a liver transplant, because livers from many donors are less suitable, due to older age or medical conditions, and are more likely to cause complications. To use these organs, we need to find better ways to preserve and test livers so that more of the available livers can be transplanted safely.
Normothermic machine perfusion (NMP) is a novel method of organ preservation which replaces the icebox, using a machine which restores the flow of blood at body temperature allowing the liver to function during storage. Previous studies have shown substantial reductions in injury and suggested that transplant surgeons could accept higher risk organs with confidence, mainly due to the ability to assess function prior to transplant. However, these studies were not primarily designed to test the effects of NMP on organ use, and there remains a need to assess fully whether this complex and expensive technology should become the standard of care.
The NMP device in this study has already been used in small numbers of transplants in the UK’s seven liver transplant units. This mostly relies upon charitable funding, because this technology has not yet been funded by NHS commissioners.
We will identify offers of donor livers less likely to be used and make the NMP machine available for storage and assessment. We will compare the proportion resulting in successful transplants with a group of offers where NMP was not used to see if a pre-defined threshold for increased use is met. We will also collect information about the cost-effectiveness of the new technology compared to the old.
Lay summary of study results: Aims
1. To see whether the normothermic machine perfusion (NMP) can increase the use of livers from high-risk donors 2. To calculate the cost of using this technology.Background
There is a shortage of donor livers available to meet the needs of the transplant waiting list. Organs from high-risk donors have a higher risk of being discarded because of uncertainty about the liver quality. Previous studies have suggested that perfusion technology (NMP) might decrease this risk. NMP is more complex and expensive than the usual technique of storing livers on ice until transplant.Method
We made NMP available for higher-risk livers to see if it decreased the risk of discard. Patients who received a liver from a higher-risk donor were consented to collect data to assess whether NMP helped make their transplant a success.Key findings
• Making NMP available increased usage of livers, but this did not meet the target we had set for the study.
• The impact on cardiac death donors was larger, meeting the target set. This appears to be due to a combination of new technologies.
• Use of NMP in livers transplanted into study participants was 31%. This was lower than the 50% we hoped for, and varied significantly between transplant centres.Conclusions
While we have shown a significant increase in liver use with NMP, the effect was lower than we hoped for. This was probably due to the device not being used as much as expected in some transplant centres. Providing NMP as a service to transplant centres may increase uptake.Sharing of results and future plans
These results were shared at the British Transplantation Society conference in March 2025, and will be published in scientific journals. Health economic results will be provided for the NHS to consider making NMP part of national transplant guidelines.REC name
South Central - Oxford C Research Ethics Committee
REC reference
21/SC/0297
Date of REC Opinion
10 Nov 2021
REC opinion
Further Information Favourable Opinion