Six-day kidney preservation in a canine model. Influence of a one-to-four-hour ex vivo perfusion interval.

Continuous hypothermic perfusion (CHP) was improved when interrupted by an interval of ex vivo perfusion. The influence of the length (1-4 hr) of this interval of ex vivo perfusion was studied in a dog model. Kidneys were subjected to CHP for 72 hr, then connected with the donor for 1, 2, 3, and 4 hr, then returned to CHP and, after a total preservation time of 144 hr, autotransplanted. Simultaneous contralateral nephrectomy was performed. Life-sustaining kidney function was obtained in all of the 6 animals in the 3-hr group and in 5 of the 6 in the 4-hr group. Shorter ex vivo perfusion intervals (1-hr and 2-hr) resulted in no survivors and 2 survivors out of 6, respectively. Creatinine levels of animals that received autotransplants of 3-hr and 4-hr ex vivo perfused kidneys returned to near normal values within 10 days after transplantation.