Extra-corporeal normothermic machine perfusion of the porcine kidney: working towards future utilization in Australasia.

BACKGROUND

The ongoing supply-demand gap with respect to donor kidneys for transplantation necessitates the increased use of higher kidney donor profile index and/or donation after circulatory death (DCD) kidneys. Machine perfusion (MP) preservation has become increasingly popular as a means to preserve such organs. Human data regarding normothermic kidney MP (NMP) is in its infancy, and such a system has not been established in the Australasian clinical setting.

METHODS

Modified cardio-pulmonary bypass technology was utilized to develop a viable NMP kidney perfusion system using a porcine DCD model. System development and optimization occurred in two stages, with system components added in each experiment to identify optimal perfusion conditions.

RESULTS

Device functionality was demonstrated by the successful perfusion of and urine production by, eight porcine kidneys. Urine production diminished in the presence of colloid in the perfusate. Pressure-controlled (compared with flow-controlled) perfusion is preferable as a safe perfusion pressure range can be maintained. More physiologic perfusion conditions are achieved if oxygenation is provided by an oxygen/carbon dioxide mixture compared to 100% oxygen.

CONCLUSION

A viable and reproducible NMP system was established and tested in porcine kidneys, which was able to simulate graft function extra-corporeally. Further work is required to identify the most optimal perfusion conditions. Prior to its utilization in clinical transplantation, the system should be tested in non-transplanted human kidneys.