Evolution of renal function in patients with cT1 renal tumors after laparoscopic partial and radical nephrectomy. Predictive factors for renal function impairment.

INTRODUCTION AND OBJECTIVES: To analyze the evolution of kidney function after laparoscopic partial nephrectomy (PN) and radical nephrectomy (RN) and to identify predictive factors for renal function impairment. MATERIALS AND METHOD: Retrospective study of patients with two kidneys, glomerular filtration rate (GFR) > 60 mL/min/1.73 m2 and single renal tumor cT1, treated in our center between 2005 and 2018. RESULTS: A total of 372 patients met the inclusion criteria for the study; 156 (41.9%) were treated with RN and 216 (58.1%) with PN. There was a difference of 26.75 mL/min/1.73 m2 in GFR between RN and PN at discharge. Age >60 years, postoperative complications (OR 2.97, p = 0.005) and RN (OR 10.03, p = 0.0001) were predictors of GFR <60 mL/min/1.73 m2 at discharge. Only RN (OR 7.69, p = 0.0001) behaved as an independent prognostic factor for GFR <45 mL/min/1.73 m2 at discharge. The median follow-up of the series was 57 (IQR 28-100) months. At the end of the follow-up period, nine (6%) patients treated with RN developed severe chronic kidney disease (CKD) and three (2%) developed end stage renal disease (ESRD). Age >70 years, diabetes mellitus (DM) (HR 2.12, p = 0.001), arterial hypertension (AHT) (HR 1.73, p = 0.01) and RN (HR 2.88, p = 0.0001) behaved as independent predictors of GFR <60 mL/min/1.73 m2. The independent predictors for GFR <45 mL/min/1.73 m2 were age >70 years, DM (HR 1.99 CI 95% 1.04-3.83, p = 0.04) and RN (HR 5.88 CI 95% 2.57-13.45, p = 0.0001). CONCLUSIONS: RN is a short- and long-term risk factor for CKD although with a low probability of severe CKD or ESRD in patients with preoperative GFR >60 mL/min/1.73 m2. Age, DM and AHT contribute to worsening renal function during follow-up.