Surgeons induce renal hypothermia during partial nephrectomy (PN) for kidney cancer to preserve remaining kidney function. According to new study findings, renal hypothermia provides no such benefit.
In a trial (NCT01529658), investigators randomly assigned 184 patients undergoing open PN for renal tumors (the majority renal cell carcinoma) to a hypothermia group or a control group. The preoperative mean measured glomerular filtration rate (mGFR) ascertained by the plasma clearance of technetium-99m-Tc-diethylenetriaminepenta-acetic acid was 87.1 vs 81.0 mL/min/1.73 m2 in the hypothermia and control group, respectively.
In the renal hypothermia group, surgeons surrounded the kidney with 2 cm or more of saline ice slush after clamping the renal hilum and allowed 10 minutes for cooling. Median clamp time was 30 vs 21 minutes in the hypothermia and control group, respectively.
The mean change in mGFR at 1 year was -6.6 vs -7.8 mL/min/1.73 m2 in the hypothermia group and control group, respectively, for a mean difference of 1.2 mL/min/1.73 m2 that was not clinically significant, Rodney H. Breau, MD, MSc, of The University of Ottawa in Ontario, Canada, and colleagues reported in The Journal of Urology. In the operated kidney, mGFR was -5.8 vs -6.3 mL/min/1.73 m2, respectively, for a mean difference of 0.5 mL/min/1.73 m2. Results were similar using estimated GFR.
Renal hypothermia did not affect the rate of surgical complications or quality of life, according to the investigators. In the hypothermia group, 1 patient received temporary hemodialysis (HD) postoperatively and 1 patient required permanent HD at 10 months. No patient in the control group required dialysis.
“Given broad eligibility criteria, our study results are generalizable and should have immediate impact for patients undergoing open partial nephrectomy,” Dr Breau’s team wrote. “Equally important, the absence of benefit observed from renal hypothermia has implications for patients undergoing laparoscopic/robotic partial nephrectomy. Our findings suggest that the inability to induce renal hypothermia during laparoscopic/robotic partial nephrectomy should not be considered a limitation of these less invasive procedures.”
Breau RH, Fergusson DA, Knoll G, et al. Hypothermia during partial nephrectomy for patients with renal tumors: a randomized controlled trial. J Urol. 205(5):1303-1309.doi:10.1097/JU.0000000000001517