Prognostic Factors for Chronic Kidney Disease After Curative Surgery in Patients With Small Renal Tumors

OBJECTIVES To investigate the incidence and predictive factors associated with newly developed chronic kidney disease (CKD) after curative surgery in patients with small renal tumors. METHODS From 1998 to 2005, we retrospectively investigated 225 patients undergoing partial nephrectomy (PN) or radical nephrectomy (RN) for renal tumors, of size :!; 4 cm, with normal contralateral kidney. The glomerular filtration rate (GFR) was calculated using the four-variable modification of diet in renal disease formula. CKD was defined as GFR of < 60 mL/min per 1.73 m(2). Demographic and clinicopathologic parameters were evaluated using Cox proportional hazards model to determine the variables independently associated with the development of postoperative CKD. RESULTS A total of 129 (57.3%) and 96 (42.7%) patients were included in the RN and PN groups. A total of 97 patients (43.1%) developed CKD; 86 (66.7%) under-went an RN and 11 (11.5%) underwent a PN. The 2-year probability of absence of CKD with an RN and a PN was 58.3% and 95.7%, respectively (P < .001). Among 20 patients with diabetes, 12 (60.0%) developed CKD: 10 patients underwent an RN and 2, a PN. The 2-year probability of absence of CKD with and without diabetes was 46.5% and 76.4%, respectively (P = .006). The multivariate analysis showed that age (P = .001), type of operation (P < .001), preoperative GFR (P = .001), and diabetes (P = .042) were associated with the development of CKD. CONCLUSIONS The results of this study show that nephron-sparing surgery for small renal mass should be attempted to prevent CKD in all eligible patients, especially those with diabetes. UROLOGY 74: 1064-1069, 2009. (C) 2009 Elsevier Inc.