Ex-vivo normothermic perfusion of a porcine kidney with three different perfusion solutions

M.B.F. Pool, T.L. Hamelink, H.G.D. Leuvenink, C. Moers

Thursday 14 march 2019

13:17 - 13:19h at Tropentheater

Categories: Klinisch/Basaal, Parallelsessie

Parallel session: Parallelsessie XV – Basaal / Klinisch 2

Background: In the Netherlands, hypothermic machine perfusion (HMP) is clinically used to preserve deceased donor kidneys. Normothermic machine perfusion (NMP) could comprise an even better kidney preservation strategy and also provides the opportunity for interventions. At this time, a suitable perfusion solution has to be established for NMP. The purpose of this study was to evaluate three different perfusion solutions and determine which solution is the most suitable for NMP.

Methods: Porcine kidneys and autologous blood were obtained from a local slaughterhouse. Warm ischaemia time was standardised at 20 min and subsequent HMP with UW-MP at 2-3 hours. Next, kidneys underwent NMP at 37°C during 7 hours, with 3 different perfusion solutions (n=5 per group). Perfusion solution 1 consisted of 350 ml red blood cells (RBCs), 500 ml Williams’ Medium E and bovine serum albumin. Perfusion solution 2 consisted of 350 ml RBCs, 250 ml of NaCl, human albumin and several electrolytes. The third perfusion solution was based on a British clinical NMP medium and consisted of 120 ml RBCs, 120 ml SAG-M, 290 ml Ringers lactate, mannitol, dexamethasone and sodium bicarbonate. Vital parameters were monitored during NMP and perfusate and urine samples were taken regularly. Biopsies were taken to assess renal histology. Thiobarbituric acid reactive substances (TBARS) and N-Acetyl-β-D Glucosaminidase (NAG) levels were measured in the perfusate samples.

Results: During perfusion all kidneys were functional and produced urine. Flow rates in group 1 and 2 were similar. The flow increased during the first hour and decreased to 250 ml/min after 7 hours of NMP. Group 3 started off with a lower flow but reached the same values as the other two groups after 7 hours. In all groups, histology showed glomerular dilatation, tubular dilatation and necrosis; consistent with ischemic injury in this donation after circulatory death model. TBARS were significantly higher in group 1 when compared to group 2 (p < 0.005) and group 3 (p < 0.005). NAG levels after 7 hours of NMP were significantly lower in group 2 in comparison with group 1 (p = 0.02) and group 3 (p = 0.01).

Conclusions: In conclusion, perfusion of porcine kidneys with three different perfusion solutions proved feasible. However, the group 2 perfusate, based on human albumin and a balanced electrolyte composition, showed the lowest levels of injury markers, indicating that this perfusate is probably most suitable for normothermic machine perfusion of a porcine kidney.