Measuring the Impact of Medical Chronic Kidney Disease and Diabetes Mellitus on Renal Functional Decline Following Surgical Management of Renal Masses

OBJECTIVE: To identify risk factors for renal functional decline following extirpative renal surgery, and establish the relative impact of these factors on glomerular filtration rate (GFR). METHODS: We reviewed 224 consecutive patients with a normal contralateral kidney who underwent radical nephrectomy for a renal mass at a tertiary care center between 2002 and 2010. Multivariate linear regression was used to identify independent predictors of renal function. RESULTS: Mean patient age at time of surgery was 62.6 years and 58% of patients were male. On multivariate analysis, preoperative GFR and diabetes mellitus (DM) were independent predictors of 1-year postoperative renal function. Every 1.0 mL/min/1.73 m(2) of preoperative GFR corresponded to a loss of 0.50 mL/min/1.73 m(2) following extirpative renal surgery. Diabetic patients had a further decrease in GFR of 4.5 mL/min/1.73 m(2) (95% confidence interval 1.5-7.6) compared to patients without DM. CONCLUSION: Preoperative GFR and DM were independent predictors of postoperative renal function. This may represent a proportion of patients with medical renal disease that is not identified on the basis of preoperative GFR alone.