This proof-of-concept study explores the feasibility and efficacy of hypothermic oxygenated machine perfusion (HMP) for preserving and evaluating en-bloc dual kidney grafts from donors after cardiac death (DCD) using an animal model. With the increasing reliance on DCD donors, there is a significant interest in organ perfusion techniques to enhance graft viability and function. The methodology involved retrieving an en-bloc dual kidney from a pig post-mortem, with a no-flow period of 35 minutes. The PerKidney machine (PerLife, Aferetica s.r.l, Bologna, Italy) facilitated the perfusion process, which was conducted in two phases: hypothermic and normothermic perfusion.
During hypothermic perfusion, a target pressure of 50 mmHg and flow of 100 ml/min were maintained, lasting 110 minutes at an average temperature of 6.8°C. Significant observations included a steady decrease in resistance from 1.07 to 0.06, indicating improved perfusion efficiency. The mean resistance was 0.37, steadily decreasing to 0.06 after 55 minutes. The normothermic perfusion, simulating transplant conditions, was performed at a target pressure of 75 mmHg and flow of 500 ml/min for 49 minutes. The kidneys showed color changes indicative of successful perfusion, demonstrating stable flow and pressure parameters. The mean resistance was 0.031, starting from 0.05 and steadily decreasing to 0.01 after 10 minutes.
The study demonstrates that hypothermic oxygenated machine perfusion for en-bloc dual kidney grafts from a DCD animal model is a viable method. The reduction in resistance during perfusion suggests enhanced organ viability, while consistent flow and pressure parameters indicate stable perfusion conditions. Observable changes in kidney color and urine production further support the effectiveness of this perfusion technique.
In this preliminary proof of concept on a large animal model, the dual kidney en-bloc perfusion appears feasible. The decreasing resistance, maintenance of flow and pressure, changes in tissue graft color and urine production during HMP are favorable characteristics supporting this option. This technique is potentially useful in situations where multiple donor organs need to be managed concurrently, and there is a lack of devices available.
The conclusion emphasizes the potential utility of HMP for en-bloc dual kidney grafts from DCD donors, particularly when multiple donor organs need to be managed concurrently. While the initial results are promising, further research is needed to refine the perfusion parameters and develop standardized evaluation methods for dual kidney grafts. This innovative approach could significantly improve graft preservation and function, ultimately enhancing transplant outcomes.
Overall, this study presents a promising new option for preserving and evaluating kidney grafts, suggesting that hypothermic oxygenated machine perfusion could be an effective method for improving the viability and functionality of kidneys from DCD donors. The findings highlight the need for more extensive studies to fine-tune the parameters and surgical preparations, and to establish a standardized method for evaluating the single parameters of each kidney in the en-bloc dual specimen. The promising preliminary results indicate that this technique could play a crucial role in improving the outcomes of kidney transplants from DCD donors.