Laparoscopic warm renal ischemia in the solitary porcine kidney model.

OBJECTIVES: To determine the effect of a laparoscopic approach on warm renal ischemia in the pig with a solitary kidney. Although the maximal safe duration for warm ischemia during open partial nephrectomy is commonly accepted to be 30 minutes, the maximal safe ischemic time during laparoscopic partial nephrectomy has not been previously determined.
METHODS: Sixteen farm pigs underwent unilateral laparoscopic right nephrectomy. Two weeks later, the pigs underwent complete laparoscopic mobilization of the remaining left kidney and were randomized to complete hilar clamp times of 0, 30, 60, or 90 minutes. Serum creatinine was evaluated before right nephrectomy and at days 0, 2, 4, 7, 14, and 30 after renal ischemia during laparoscopy. All renal specimens were evaluated by an experienced nephropathologist in a blinded fashion.
RESULTS: The serum creatinine remained stable at all points in the control and 30-minute ischemia groups. The serum creatinine level rose initially on days 2 and 4 in the 60-minute and 90-minute ischemia groups but returned to baseline by day 7. At harvest, no statistically significant difference was found among the groups in serum creatinine or histologic features.
CONCLUSIONS: Renal ischemic times up to 90 minutes during laparoscopy were well tolerated by the solitary porcine kidney. Possible explanations for this finding include the protective effect of a solitary kidney and the potential protective effect of relative ischemic preconditioning provided by the pneumoperitoneum.