Preservation of renal function following partial or radical nephrectomy using 24-hour creatinine clearance

OBJECTIVE: To compare the effect on renal function of partial and radical nephrectomy using creatinine clearance measurements from 24-hr urine collection. METHODS: All patients with a solid enhancing renal mass suspicious for renal cell carcinoma, a normal contralateral kidney, and not dialysis dependent were enrolled in this prospective cohort study. Patients were treated with partial or radical nephrectomy by one urologist. Creatinine clearance (CrCl) measurements were prospectively obtained by 24-hr urine collection preoperatively, and at 3, 6, and 12 mo postoperatively. Mean change in creatinine clearance from baseline was compared at 3, 6, and 12 mo. Serum creatinine and Cockcroft-Gault calculations were also performed for comparison. Mixed model analysis incorporating patient and tumor characteristics and the procedure type was performed in SAS Version 9.1. RESULTS: Sixty-three consecutive patients were enrolled in this study. The partial nephrectomy (n=26) and radical nephrectomy (n=37) groups were similar with respect to age, sex, presence of hypertension, vascular disease, diabetes mellitus, and angiotensin converting enzyme inhibitor or receptor blocker use. The postoperative change in creatinine clearance was significantly less (p-value < 0.0001) in the partial nephrectomy group (-0.09mL/s, -6.1%) compared to the radical nephrectomy group (-0.56mL/s, -31.6%). Linear regression analysis showed intervention type (partial vs. radical nephrectomy) was the most significant predictor of change in creatinine clearance (p-value < 0.0001). CONCLUSIONS: There is significantly less deterioration in the overall renal function of patients who are treated with partial nephrectomy compared to radical nephrectomy. This highlights the importance of performing nephron-sparing surgery on appropriate patients.