Recovery of renal function after complete renal hilar versus artery alone clamping during open and laparoscopic surgery

PURPOSE: It is generally accepted that simultaneous occlusion of the renal artery and vein during warm ischemia is more damaging than occlusion of the artery alone. Pneumoperitoneum during laparoscopy may impair venous backflow, negating the benefits of clamping the artery alone. We evaluated the effect of laparoscopic vs open surgery on the recovery of renal function after clamping of the renal artery and vein, and the artery alone in a solitary kidney porcine model. MATERIALS AND METHODS: Right laparoscopic nephrectomy was performed in 36 pigs. After a 12-day recovery period the animals were randomized into 3 groups, including 1) 120-minute warm ischemia with renal artery and vein occlusion, 2) 120-minute warm ischemia with artery alone occlusion and 3) control sham surgery. The groups were further subdivided into an open and a laparoscopic arm. Serum creatinine was assessed preoperatively, and on postoperative days 1, 3, 8 and 15. RESULTS: Artery alone clamping resulted in a significantly lower serum creatinine increase on postoperative days 1 and 3 in the open arm compared to the laparoscopic arm. Compared to open renal artery and vein clamping the increase in serum creatinine for open artery alone clamping was also significantly lower on postoperative days 1 and 3. No significant difference in postoperative serum creatinine was found between the laparoscopic artery alone, and the renal artery and vein arms at any time point. No significant serum creatinine changes were observed in the control sham surgery group compared to preoperative values at all followup time points. CONCLUSIONS: In this porcine model clamping of the artery alone during open surgery better protected the kidney from warm ischemia compared to renal artery and vein occlusion. This benefit was not observed during laparoscopic surgery. We speculated that the presence of pneumoperitoneum causes at least partial occlusion of the renal vein, thus, negating the benefit of renal artery clamping only.