Advice

Clinical and technical evidence

Clinical and technical evidence

A literature search was carried out for this briefing in accordance with the interim process and methods statement. This briefing includes the most relevant or best available published evidence relating to the clinical effectiveness of the technology. Further information about how the evidence for this briefing was selected is available on request by contacting mibs@nice.org.uk.

Published evidence

There are 6 studies summarised in this briefing, including 483 livers. Five studies were prospective non‑randomised clinical studies and 1 was a randomised controlled trial.

The clinical evidence and its strengths and limitations is summarised in the overall assessment of the evidence.

Overall assessment of the evidence

The evidence base for the technology is of moderate methodological quality.

Three of these studies are based in the UK NHS. All clinical studies suggest that the device may help increase the number of donor livers that can be successfully transplanted.

Further evidence would benefit from sufficiently powered sample sizes, use of high-risk organs, randomisation at time of organ donation and appropriate long-term follow ups to improve the evidence base. No studies were found that showed the benefit of the OrganOx metra compared with other machine perfusion devices.

Nasralla et al. (2018)

Intervention and comparator

OrganOx metra and static cold storage.

Key outcomes

Livers were randomised into 2 arms: normothermic machine perfusion (NMP) using the OrganOx metra, and static cold storage (SCS). The results showed that the organ discard rate was statistically significant between groups. The SCS group had a 24.1% discard rate and NMP had a 11.7% discard rate. There was a significant reduction in peak aspartate aminotransferase and early allograft dysfunction rates in NMP livers compared with the SCS group.

Strengths and limitations

Two authors are co-founders of OrganOx Limited, but their roles in this study did not involve selection, recruitment or transplant.

Reiling et al. (2020)

Intervention and comparator

OrganOx metra. No comparator.

Key outcomes

Ten donor livers that were considered unsuitable for transplant had 4 hours of perfusion using OrganOx metra. Graft viability was reassessed using haemodynamic, metabolic and synthetic parameters. All 10 were then considered acceptable and since transplant they all function satisfactorily.

Strengths and limitations

No competing interests were declared.

Bral et al. (2019)

Intervention and comparator

OrganOx metra using back-to-base approach compared with immediate NMP.

Key outcomes

The primary outcome measure was safety as defined by 30‑day patient and graft survival. Secondary outcomes included 90‑day graft survival; incidence of early allograft dysfunction; and biliary and arterial complications at 6 months. Results showed no difference in graft function, incidence of complications or graft and patient survival in back-to-base approach compared with immediate NMP.

Strengths and limitations

Excluding 3 livers from the statistical analysis may have introduced bias into the results. The limited sample size is not adequately powered to support definitive conclusions for non-inferiority of a back-to-base approach compared with local NMP.

Ceresa et al. (2019)

Intervention and comparator

OrganOx metra used with post-SCS.

Key outcomes

The primary end point was to test the safety and feasibility of the post-SCS normothermic perfusion approach. Results showed a 94% 30‑day graft survival rate, supporting safety and feasibility of the device. Secondary end points included early allograft dysfunction, need for renal replacement therapy and adverse events.

Strengths and limitations

The study is not sufficiently powered to detect small differences between the 2 different approaches of OrganOx metra usage. The small sample size also precludes subgroup analyses. Retrospective comparison with historical cohorts is a recognised limitation by the authors.

Cardini et al. (2020)

Intervention and comparator

OrganOx metra.

Key outcomes

From 34 donor livers, 9 were discarded because of poor performance during NMP. There were 25 organs successfully transplanted after preservation of up to 38 hours. Extended criteria donor rates were 100% and 92% in discarded and transplanted livers. Graft and patient survival at 20 months was 88%.

Strengths and limitations

The sample size is not large enough for statistical significance.

Mergental et al. (2020)

Intervention and comparator

OrganOx metra and standard SCS.

Key outcomes

There were 31 discarded livers assessed using OrganOx metra, and 22 (71%) were found to meet viability criteria and were transplanted. Viability testing with NMP allowed successful transplantation of 71% of discarded livers, with 100% 90‑day patient and graft survival. There were 4 individuals who developed biliary structures that needed re-transplantation.

Strengths and limitations

The study did not include people who were at higher risk with marginal organs. Three authors declared involvement in OrganOx in various capacities.

Sustainability

The company did not report any sustainability benefits.

Recent and ongoing studies