To determine whether ischemia preconditioning (IPC) confers resilience to subsequent renal warm ischemia (WI) in a single-kidney porcine model.

After right nephrectomy was performed, 20 female pigs were randomized to 5 groups: group 1: 60 minutes IPC followed by 90 minutes WI; group 2: 25 minutes IPC followed by 90 minutes WI; group 3: no IPC and 90 minutes WI; group 4: 60 minutes IPC, no WI; and group 5: no IPC, no WI (sham control procedure). Ischemia preconditioning was performed for 60 minutes (4 minutes clamping followed by 11 minutes reperfusion) or 25 minutes (10 minutes clamping followed by 15 minutes reperfusion). Serum creatinine values were obtained preoperatively and on postoperative day (POD) 1, 3, 8, and 15.

Mean serum creatinine values were comparable between groups on POD 1, with the exception of group 1, which was significantly worse than group 5 (control). On POD 3, renal function was similar between groups 1 and 2, and both were significantly worse than groups 4 and 5. On POD 8, renal dysfunction in group 1 was significantly worse than in group 3. All four animals from group 1 were killed after POD 8 because of overwhelming renal insufficiency.

Ischemia preconditioning did not suggest increased renal resilience to the kidney after subsequent prolonged WI. Our results further suggest that the protection provided by IPC in smaller animals is not appreciated in a larger-animal, single-kidney model. The additive effect of further ischemic insults was more deleterious to the remaining renal unit.