Renal Normothermic Machine Perfusion: The Road Toward Clinical Implementation of a Promising Pretransplant Organ Assessment Tool.

The increased utilization of high-risk renal grafts for transplantation requires optimization of pretransplant organ assessment strategies. Current decision-making methods to accept an organ for transplantation lack overall predictive power and always contain an element of subjectivity. Normothermic machine perfusion (NMP) creates near-physiological conditions, which might facilitate a more objective assessment of organ quality before transplantation. NMP is rapidly gaining popularity, with various transplant centers developing their own NMP protocols and renal viability criteria. However, to date, no validated sets of on-pump viability markers exist nor are there unified NMP protocols. This review provides a critical overview of the fundamentals of current renal NMP protocols and proposes a framework to approach further development of ex vivo organ evaluation. We also comment on the potential logistical implications of routine clinical use of NMP, which is a more complex procedure compared with static cold storage or even hypothermic machine perfusion.

Hamelink TL ，Ogurlu B ，De Beule J ，Lantinga VA ，Pool MBF ，Venema LH ，Leuvenink HGD ，Jochmans I ，Moers C ... -  《-》

Normothermic machine perfusion of the kidney.

Weissenbacher A ，Hunter J 《-》

Optimizing porcine donor kidney preservation with normothermic or hypothermic machine perfusion: A systematic review.

We present an updated overview of the literature comparing normothermic with hypothermic machine perfusion in porcine kidneys. We conducted a systematic literature review in Embase, Medline Epub (Ovid), Cochrane Central, Web of Science, and Google Scholar on studies comparing normothermic (NMP) to hypothermic machine perfusion (HMP) in porcine kidneys. A meta-analysis was judged inappropriate because of heterogeneity in study design and perfusion methods. The quality of evidence of each included study was assessed. We included 8 studies. One out of 5 studies reported a significant difference in peak renal blood flow in favor of NMP. Oxygen consumption was significantly higher in NMP kidneys in 2 out of 5 studies. Peak creatinine clearance in NMP was significantly higher than that in HMP in 1 out of 6 studies. Two out of 4 studies reported a higher degree of epithelial vacuolation in kidneys receiving NMP over HMP. None of the studies found a significant difference between NMP and HMP in peak serum creatinine or graft survival after autotransplantation. The results need to be interpreted with caution in view of the diversity in perfusion protocols, the low quality of evidence, and the limited sample sizes.

Bouari S ，Eryigit Ö ，de Bruin RWF ，IJzermans JNM ，Minnee RC ... -  《-》

Normothermic ex vivo perfusion of deceased donor kidneys and its clinical potential in kidney transplantation outcomes.

Unes M ，Kurashima K ，Caliskan Y ，Portz E ，Jain A ，Nazzal M ... -  《-》

Normothermic kidney perfusion: An overview of protocols and strategies.

Normothermic machine perfusion (NMP) technologies are emerging as an important adjunct in organ preservation and transplantation. NMP can enable the reduction or avoidance of cold ischemia and allows for pretransplant measurement of function and metabolic status to assess the suitability of the organ for transplantation. The key requirement of NMP is to provide an environment that is protective to the organ, ensures optimal oxygen delivery and supports metabolic function. Red blood cell-based solutions, artificial hemoglobin solutions, and acellular solutions have all been utilized in NMP. However, there is no clear consensus on perfusion protocols. A period of NMP after hypothermic preservation is the most commonly used strategy. As an alternative, several groups have developed and tested the feasibility of more prolonged periods of NMP. There are only a few reports of the application of NMP in clinical kidney transplantation and each uses different approach and conditions. This review details the rationale for NMP protocols considering duration of NMP and different perfusate compositions in experimental and clinical models. We also include a discussion on the mechanistic action of NMP, comparison of subnormothermic and hypothermic conditions, the different logistical approaches and future requirements.

Elliott TR ，Nicholson ML ，Hosgood SA 《-》