Warm ischemia time length during on-clamp partial nephrectomy: does it really matter?

Area of Science:

• Nephrology
• Urology
• Surgical Oncology

Background:

• The effect of warm ischemia time (WIT) on kidney function after partial nephrectomy (PN) is debated.
• This study investigates the long-term renal functional outcomes associated with WIT exceeding 30 minutes during on-clamp PN.

Purpose of the Study:

• To evaluate the impact of prolonged warm ischemia time (WIT > 30 min) on long-term renal function.
• To compare renal functional recovery and chronic kidney disease (CKD) progression in patients undergoing on-clamp partial nephrectomy (PN) with varying WIT durations.

Main Methods:

• A multicenter, retrospective analysis of 3526 patients undergoing on-clamp PN (2000-2018).
• Patients with two kidneys, single cT1 tumor, and preoperative eGFR ≥60 mL/min/1.73m² were stratified by WIT ≤30 min or >30 min.
• Propensity-score matched analysis (1:1) compared eGFR, eGFR preservation, CKD upgrading, and CKD-free progression rates.

Main Results:

• After propensity-score matching, no significant differences in median eGFR values at 1, 3, 5, and 10 years were observed between WIT groups.
• eGFR preservation, absolute eGFR change, and 5-year CKD-free progression rates were comparable between groups.
• WIT > 30 min was not a predictor of overall CKD upgrading or progression to stage ≥III CKD.

Conclusions:

• Warm ischemia time duration during on-clamp partial nephrectomy does not affect long-term renal function outcomes.
• This finding applies to patients with two kidneys and adequate preoperative renal function (eGFR ≥60 mL/min/1.73m²).