Comparison of methods for preservation of renal function during ischemic renal surgery

Three methods of providing in situ protection to an ischemic kidney were compared in dogs. These were surface cooling using external coils, transvenous hypothermic perfusion and intravenous inosine. The dogs were divided into 3 groups with 20 dogs in each group. Group 1 had the artery occluded for 45 minutes, group 2 for 60 minutes and group 3 for 90 minutes. A further control group of 5 dogs underwent mobilization of the left kidney without ischemia. Contralateral nephrectomy was performed on all animals. The 20 dogs in each group were randomized; 5 undergoing surface cooling, 5 cooling by renal vein perfusion, 5 receiving intravenous inosine and 5 receiving no protection. Function of the solitary kidney was monitored by serum creatinine levels. All 3 methods provided significant protection. Protection provided by surface cooling and inosine was greater than by venous cooling. The protection provided by intravenous inosine was similar to surface cooling for up to 60 minutes but was less at 90 minutes.