Simultaneous Ex Situ Normothermic Perfusion of Paired Kidneys in Pigs.

Abstract

Background: Normothermic Machine Perfusion (NMP) is essential in renal transplantation to improve organ viability before transplantation. This study presents a proof of concept for simultaneous ex situ perfusion of paired porcine kidneys using exogenous creatinine and iohexol clearances to assess renal function, with the primary objective of examining intra-individual differences.

Methods: Five kidney pairs (n = 10) were harvested from pigs, preserved at 4°C for 3 h, and subjected to 6-h NMP. Each pair was perfused with a solution containing red blood cells, and perfusion parameters were monitored continuously. Biochemical parameters were assessed using hourly perfusate and urine samples. Kidney function was evaluated using creatinine, which was introduced during the priming procedure.

Results: No significant differences were observed between paired kidneys in terms of perfusion and biochemical parameters. Both kidneys maintained stable mean arterial pressures (67.40 ± 12.08 mmHg for right vs. 71.50 ± 4.36 mmHg for left) and flows (68.90 ± 38.61 mL/min vs. 54.00 ± 26.08 mL/min), with consistent electrolyte balance and pH levels. The high inter-individual variability in perfusion and biochemical parameters underscores the importance of paired comparisons.

Conclusions: This pig model of simultaneous NMP of paired kidneys demonstrates that the intra-individual variance is low, which makes it possible to test treatments prior to kidney transplantation using one kidney as a valid comparator of the other.