PROlonged normothermic machine PERfusion of human discarded donor kidneys: first results of the PROPER study

A.S. Arykbaeva, D.K. de Vries, J.B. Doppenberg, V.A.L. Huurman, R.C. Minnee, C. Moers, R.A. Pol, H.G.D. Leuvenink, R.J. Ploeg, I.P.J. Alwayn

Wednesday 4 march 2020

16:20 - 16:30h at Joep Nicolas zaal

Parallel session: Parallel sessie VII – Basale- en Klinische abstracts

Background: In order to utilize the regenerative potential of kidneys on normothermic machine perfusion (NMP), continuous perfusion beyond 1-hr is warranted. The aim of this study is to test safety and feasibility of a newly developed PROPER protocol of 6-hrs of prolonged NMP using discarded human donor kidneys.

Methods: Discarded deceased donor kidneys (n=15) were perfused for 6h. A pulsatile pressure of 75mmHg at 37°C using an open drainage system and oxygenated with 95%O2/5%CO2 was used. As a starting point, the clinically applied 1 hour protocol as previously published by Hosgood et al. was applied for prolonged perfusions in group 1 (n=5) kidneys. Based on the first results and early modifications, the PROPER protocol was developed. Group 2 (n=10) kidneys were perfused with this modified perfusate, including crucial adjustments such as washing the red blood cells (RBCs) and the addition of albumin. When urine was produced, this was recirculated. Renal flow, perfusate parameters, and histologic assessment were recorded.

Results: No statistically significant demographic differences were found between the groups. No significant change in flow was observed in group 1 after start of perfusion to t=6h (70±34 vs 60±28 ml/min/100gr, p=0.51), however, it increased significantly in group 2 (54±35 vs 114±37 ml/min/100gr, p=0.001). There was a trend of more urine production in group 2 (cumulative 399±371 and 130±160 ml, p=0.07). Compared to group 1, group 2 kidneys maintained a more stable and physiological pH and sodium levels at 6h. Potassium levels in group 1 at t=0 and t=6hrs remained high (11.8±2.4 vs 13.1±1.9 mmol/L, p=0.42), compared to group 2 (1.9±1.8 vs 5.8±1.6 mmol/L, p=0.001).

Conclusions: This study shows that prolonged end-ischemic NMP is feasible and potentiates assessment of the kidney. It also demonstrates that for prolonged NMP an adapted perfusate is required to maintain stable flow. Therefore, we strongly recommend the addition of albumin, urine-recirculation and washed RBCs for longer perfusions.