Baseline renal function, ischaemia time and blood loss predict the rate of renal failure after partial nephrectomy

OBJECTIVE To identify independent predictors of renal failure after partial nephrectomy (PN) in patients with renal cell carcinoma (RCC). PATIENTS AND METHODS Data were available for 166 patients with pathological T1-3 N0M0 RCC treated with PN. Renal failure after PN was defined as a decrease in glomerular filtration rate (GFR) of >25% (RIFLE criteria). The GFR before and after PN was estimated using the Modification of Diet in Renal Disease study group equation. Univariable and multivariable logistic regression models were used to assess a decrease of >25% in GFR from the preoperative level. Candidate predictor variables were age, gender, PN indication (absolute vs relative), preoperative GFR, tumour size, perioperative blood loss, surgery duration and clamping time. RESULTS After PN, 22 (13.3%) patients had a decrease in GFR of >25%. The perioperative blood loss (P = 0.02), clamping time (P = 0.04) and preoperative GFR (P = 0.002) were independent predictors of a decrease in GFR of >25%. CONCLUSIONS We identified two important potentially modifiable variables that should be considered in the planning of PN, i.e. the clamping time and blood loss. It is possible that selective referral to experienced surgeons who can perform PN within short surgical and clamping times, and with minimal blood loss, could minimize the rate of renal failure, especially in patients with an underlying renal function impairment.