Impact of cold and warm ischemia on postoperative recovery of affected renal function after partial nephrectomy

Purpose: To determine the influence of warm or cold ischemia on postoperative renal function, we conducted preoperative and postoperative analysis by renal scintigraphy of patients who were undergoing open partial nephrectomy (OPN) and laparoscopic partial nephrectomy (LPN). Patients and Methods: From May 2005 to February 2010, the preoperative and postoperative renal function was evaluated by 99mTc-mercaptoacetyltriglycine (MAG3) clearance in 37 patients who were treated with OPN (n=13) and LPN (n=24). LPN were achieved via retroperitoneal (RPLPN; n=12) or transperitoneal (TPLPN; n=12) routes. Renal cooling was performed after renal hilar clamping in OPN and RPLPN, but not TPLPN. Renal function was evaluated according to the ratio of affected to contralateral renal MAG3 clearance. Results: Mean ischemic time was 29.5 minutes in OPN, 25.5 minutes in TPLPN, and 50 minutes in RPLPN (P<0.01); median blood loss was 230 mL in OPN (P<0.05), 110 mL in TPLPN, and 53 mL in RPLPN. There was no significant difference in postoperative total renal function between the groups. Although ischemic time in RPLPN was longer than in TPLPN, the postoperative recovery of affected renal function from 1 week to 3 months for RPLPN and OPN (cold ischemia) was significantly better than for TPLPN (P<0.01). Conclusions: Cold ischemia has an advantage of postoperative recovery of affected renal function. If a patient has a risk of renal dysfunction, cold ischemia during renal hilar clamping is recommended to avoiding deterioration.