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

PURPOSE: To evaluate renal function and to identify factors associated with renal dysfunction in the elective indications setting of nephron-sparing surgery (NSS).
METHODS: 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.
RESULTS: 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.
CONCLUSION: Non- or time-limited clamping techniques are associated with preservation of renal function in the elective indications setting of NSS.