Are warm ischemia and ischemia time still predictive factors of poor renal function after partial nephrectomy in the setting of elective indication?

To evaluate renal function and to identify factors associated with renal dysfunction in the elective indications setting of nephron-sparing surgery (NSS). We retrospectively reviewed operative data and glomerular filtration rate (GFR) of 519 patients treated by NSS in an elective indications setting between 1984 and 2006 in eight academic institutions. A GFR decrease under the thresholds of 60 or 45 ml/min at last follow-up was considered a significant renal dysfunction. Univariate and multivariate regression models were used to assess multiple factors of renal function. Median age, tumor size, preoperative, and final GFR were 59.5 years (27-84), 2.7 cm (0.9-11), 79 (45-137), and 69 ml/min (p < 0.0001), respectively, with a median follow-up of 23 months (1-416). Hilar clamping was performed in 375 procedures (72.3 %). Significant GFR decrease was observed in 89 patients (17.1 %). Median operating time, hilar clamping duration, and blood loss were 137 min (55-350), 22 min (0-90), and 150 ml (0-4150), respectively. At univariate analysis, age (p = 0.002), preoperative GFR (p = 0.001), pedicular clamping (p = 0.01), and ischemia time (p = 0.0001) were associated with renal dysfunction. Age (p = 0.004; HR 1.2), pedicular clamping (p = 0.04; HR 1.3), and ischemia time (p = 0.0001; HR 1.8) remained independent risk factors for renal function deterioration in multivariate analysis. Non- or time-limited clamping techniques are associated with preservation of renal function in the elective indications setting of NSS.