Renal function outcomes in patients treated with partial nephrectomy versus percutaneous ablation for renal tumors in a solitary kidney

Purpose: Partial nephrectomy is the recommended management for small renal masses. Percutaneous ablation is safe and effective with comparable short-term cancer specific survival. Currently to our knowledge data are lacking on the impact of thermal ablation on renal function preservation. We examined the impact on renal function of partial nephrectomy vs percutaneous ablation in patients with a solitary kidney. Materials and Methods: We performed a retrospective review to identify patients with a solitary kidney who underwent partial nephrectomy or percutaneous ablation at Mayo Clinic Rochester between 2003 and 2009. Preoperative characteristics and 3-month posttreatment renal function were compared using the Wilcoxon rank sum, chi-square and Fisher exact tests. Results: During the study period 50 patients underwent percutaneous ablation and 62 underwent partial nephrectomy. At partial nephrectomy no ischemia was used in 30 cases (48%), a median of 28 minutes of cold ischemia was used in 26 (42%) and a median of 18 minutes of warm ischemia was used in 6 (10%). Patients who underwent partial nephrectomy were younger (median age 62.5 vs 68.5 years, p = 0.01) and harbored larger tumors (median 3.5 vs 2.5 cm, p = 0.005) with higher nephrometry scores (median 9 vs 7, p = 0.03). At 3-month posttreatment followup no differences were noted between the 2 groups in glomerular filtration rate (p = 0.91), change in glomerular filtration rate (p = 0.77) or change in chronic kidney disease stage (p = 0.87). Similar results were observed when adjusting for age, tumor size and nephrometry score on multivariate analysis. Conclusions: With judicious use of ischemia partial nephrectomy, even for more complex tumors, has short-term renal function outcomes similar to those of percutaneous ablation.