Renal Protection Against Ischemia Reperfusion Injury: Hemoglobin-based Oxygen Carrier-201 Versus Blood as an Oxygen Carrier in Ex Vivo Subnormothermic Machine Perfusion

Static cold storage is generally used to preserve kidney allografts from deceased donors. Hypothermic machine perfusion may improve outcomes after transplantation, but few sufficiently powered prospective studies have addressed this possibility. In this international randomized, controlled trial, we randomly assigned one kidney from 336 consecutive deceased donors to machine perfusion and the other to cold storage. All 672 recipients were followed for 1 year. The primary end point was delayed graft function (requiring dialysis in the first week after transplantation). Secondary end points were the duration of delayed graft function, delayed graft function defined by the rate of the decrease in the serum creatinine level, primary nonfunction, the serum creatinine level and clearance, acute rejection, toxicity of the calcineurin inhibitor, the length of hospital stay, and allograft and patient survival. Machine perfusion significantly reduced the risk of delayed graft function. Delayed graft function developed in 70 patients in the machine-perfusion group versus 89 in the cold-storage group (adjusted odds ratio, 0.57; P=0.01). Machine perfusion also significantly improved the rate of the decrease in the serum creatinine level and reduced the duration of delayed graft function. Machine perfusion was associated with lower serum creatinine levels during the first 2 weeks after transplantation and a reduced risk of graft failure (hazard ratio, 0.52; P=0.03). One-year allograft survival was superior in the machine-perfusion group (94% vs. 90%, P=0.04). No significant differences were observed for the other secondary end points. No serious adverse events were directly attributable to machine perfusion. Hypothermic machine perfusion was associated with a reduced risk of delayed graft function and improved graft survival in the first year after transplantation. (Current Controlled Trials number, ISRCTN83876362.) 2009 Massachusetts Medical Society

Ex vivo normothermic perfusion (EVNP) is a novel method of preservation that restores circulation and allows an organ to regain function prior to transplantation. The aim of this study was to assess the effects of EVNP in kidneys from marginal donors. Eighteen kidneys from extended criteria donors (ECD) underwent a period of EVNP immediately before transplantation. Kidneys were perfused with a plasma free red-cell based solution at a mean temperature of 34.6°C. The outcome of these kidneys was compared to a control group of 47 ECD kidneys that underwent static cold storage (CS). The mean donor age was 61 ± 1 years in the EVNP and 62 ± 6 years in the CS group (p = 0.520). EVNP kidneys were perfused for an average of 63 ± 16 min and all were transplanted successfully. The delayed graft function rate (DGF), defined as the requirement for dialysis within the first 7 days was 1/18 patients (5.6%) in the EVNP group versus 17/47 (36.2%) in the CS group (p = 0.014). There was no difference in graft or patient survival at 12 months (p = 0.510, 1.000). This first series of EVNP in renal transplantation demonstrates that this technique is both feasible and safe. Our preliminary data suggests that EVNP offers promise as a new technique of kidney preservation.

The brains of humans and other mammals are highly vulnerable to interrupted blood flow and decreased oxygen levels. Here, we describe the restoration and maintenance of microcirculation and molecular and cellular functions of the intact porcine brain under ex vivo normothermic conditions up to 4-hours postmortem. We developed an extracorporeal pulsatile-perfusion system and a hemoglobin-based, acellular, non-coagulative, echogenic, and cytoprotective perfusate that promotes recovery from anoxia, reduces reperfusion injury, prevents edema, and metabolically supports the energy requirements of the brain. Employing this system, we observe preservation of cytoarchitecture; attenuation of cell death; and restoration of vascular dilatory and glial inflammatory responses, spontaneous synaptic activity, as well as active cerebral metabolism in the absence of global electrocorticographic activity. These findings demonstrate that under appropriate conditions the isolated, intact large mammalian brain possesses a yet underappreciated capacity for restoration of microcirculation and molecular and cellular activity after a prolonged postmortem interval.