I. Palma1, J. Woloszyn1, R. Abbott1, Y. Smolin1, R. Ramsamooj2, N. Tran2, C. Santhanakrishnan1, R. V. Perez1 1University Of California – Davis,Surgery,Sacramento, CA, USA 2University Of California – Davis,Pathology And Laboratory Medicine,Sacramento, CA, USA
Introduction: Hypothermic storage of organs has been a gold standard for organ preservation in transplantation. However, recent studies have shown that EVNP has the potential to repair and assess the viability of marginal organs prior to transplantation by restoring normal metabolism. The optimal perfusion solution for these functions has not been determined.
Methods: Paired high risk human kidneys (n=8) deemed unsuitable for transplantation were placed on 3 hours of pressure dependent EVNP with a centrifugal pump at 37°C. Kidney was oxygenated via a hollow fiber membrane oxygenator and supplemented with parenteral nutrition & insulin. Kidneys were perfused with leukocyte depleted packed red blood cells (PRBC) as an optimal “repair” solution or whole blood (WB) to more accurately assess viability during early reperfusion. Exogenous creatinine (0.06 g) was added to the system to assess glomerular clearance. Pump parameters and urine output were monitored. Blood and urine samples were collected at the start and every 30 minutes and analyzed for pH, oxygen, electrolytes, creatinine, lactate and neutrophil gelatinase associated lipocalin (NGAL) using a Triage point of care machine. NGAL is an acute kidney injury biomarker. Results were compared between groups using a general linear model for repeated measures test.
Results:The mean age of donors was 60 years. The mean static cold ischemia time was 52.5 hours. The Maryland Aggregate Pathology Index and Kidney Donor Prognostic Index were equal in both groups (5.25 and 87% respectively). Hemodynamic parameters evaluated were flow and resistance, and neither showed statistical significance (p=0.19 and p=0.20). However, PRBC showed a better trend in both parameters. Functional parameters appeared more favorable in the PRBC group but only achieved statistical significance with urine NGAL as shown in Table 1.
Conclusion:EVNP of high-risk kidneys is possible and combined with POC testing offer a means of assessing organs in real time, potentially making it possible to transplant organs that previously were thought to be untransplantable. Perfusion with PRBC may have a beneficial effect on the kidney, but may not accurately assess the degree of ischemia-reperfusion injury when compared to the more physiologic WB perfusion. More studies are warranted to determine the contributing factors and clinical usefulness of urinary biomarkers such as NGAL during EVNP.
