Purpose: This study was designed to compare the effectiveness of two methods of inducing renal hypothermia through laparoscopy in pigs and humans.
Materials and Methods: Twelve pigs were divided into four groups of three animals each. Both kidneys of the animals in Groups A, B, and C were submitted to pelvic irrigation with cold saline (4°C) for 20 minutes, with flow rates of 5 mL/min, 10 mL/min, and 15 mL/min, respectively. In Group D renal hypothermia was induced by intracorporeal ice slush applied to the surface for 20 minutes. All maneuvers were performed laparoscopically and renal cortex temperature was measured by a thermocouple needle. Five human patients also underwent laparoscopic partial nephrectomy due to renal cell carcinoma. In one case renoprotection was induced by retrograde endoscopic cold saline perfusion at a flow rate of 10 mL/min. In the remaining four patients we induced renal hypothermia via laparoscopic application of ice slush. The renal temperature of the human patients was also monitored using a thermocouple needle.
Results: In the pigs, at 20 minutes of renal pelvis perfusion the mean renal temperature, the temperature drop, and saline flow per gram of kidney were: Group A, −29.5°C ± 1.1 (−6.3°C; 0.10 mL); Group B, −22.8°C ± 1.1 (−13.1°C; 0.22 mL); and Group C, −21.1°C ± 0.9 (−14.9°C; 0.31 mL). In Group D the mean renal cortex temperature at 20 minutes was 13.6°C ± 1.2, a drop of −22.5°C. There were striking differences among the groups (P < 0.0001). The laparoscopic partial nephrectomy was uneventful in all five human patients. The lowest renal cortex temperature was 32.5°C, seen in the patient who submitted to pelvic irrigation with cold saline, and the mean temperature drop was 19.1°C ± 2.5°C in the patients who submitted to ice slush–induced renal hypothermia.
Conclusions: Induction of renal hypothermia using intracorporeal ice slush confers lower kidney temperatures than endoscopically-induced cold saline perfusion.
