Maximizing kidneys for transplantation using machine perfusion: from the past to the future: A comprehensive systematic review and meta-analysis.

Medicine 2016; 95(40): e5083.

Aims
To conduct a systematic review and meta-analysis to explore the benefits of machine perfusion (MP) preservation with and without oxygenation, and/or under normothermic conditions, when compared with cold storage (CS) prior to deceased donor kidney transplantation.

Interventions
The databases EMBASE, Medline, and Cochrane (1980–December 2015) were searched for clinical (human) studies in the presence of MP data, and experimental (animal) studies in the presence of comparative data either between different types of MP, and/or MP and an alternative form of preservation. Both English and non-English articles were considered, utilising a translator if necessary and only published works, not conference abstracts were included.

Participants
101 studies (63 human and 38 animal) were included in the analysis.

Outcomes
Measured outcomes in the human studies included the incidence of delayed graft function, primary nonfunction, 1-year graft and patient survival in the whole cohort, acute rejection rates and posttransplant renal function. Outcomes measured in the animal studies included markers of inflammation, oxidative stress markers, microcirculatory tissue perfusion post-preservation, oxygen consumption, histology, animal survival and parameters of renal function, renal tubule, glomerular, and endothelial injury.

Follow-up
1 year

CET Conclusions
This systematic review was well conducted; there was prospective registration, searching multiple databases, duplicate data extraction, forests plots for publication bias, and stratification by donor type. The title is a little misleading, as it says “maximizing kidneys for transplantation” but the paper focusses on transplant outcomes rather than increasing the donor pool or reducing discard rates. The paper also tries to cover a number of interventions in both humans and animals, and in the end describes only one human study of warm perfusion amongst the other 100 studies included. The included studies were assessed for quality and risk of bias, but this is not clearly represented in the report for readers to refer to. The included animal studies were very heterogenous and one would question the value of meta-analysis for a small number of studies in different animals, conducted in different ways. They were also subject to bias as key domains could not be assessed from the published reports. Overall it is a good paper which perhaps tries to cover too much ground.

Quality notes
Quality assessment not appropriate

Trial registration
PROSPERO — CRD42016037100

Funding source
Non-industry funded