The preoperative stratification of patients based on renal scan data is unable to predict the functional outcome after partial nephrectomy

ABSTRACT Introduction: eGFR-categories are used to predict functional outcome after partial nephrectomy (PN); no study categorized patients according to preoperative renal scan (RS) data. Aim of the study was to evaluate if stratification of patients according to RS is a reliable method to predict minor/major loss of renal function after PN. Materials and Methods: We considered patients who underwent PN and RS pre-/post-PN for T1 tumor in our Institution (2007-2017). Demographics, perioperative and specifically functional data were analysed. On the basis of the baseline Split Renal Function (SRF), patients were stratified into risk-categories: 1) baseline operated-kidney SRF range 45-55%; 2) baseline operated-kidney SRF <45%. Risk categories were analysed with postoperative functional outcome: postoperative operated-kidney SRF decrease below 90% of baseline was considered significant loss of function. Contingency tables and univariate/multivariate regression were analysed looking for independent factors of postoperative functional impairment. Results: 224 patients were analysed, 125 (55.8%) maintained >90% of their baseline function. Worse probability of maintaining ≥90 baseline renal function was found in patients with Charlson's Comorbidity Index (CCI≥3) (p=0.004) and patients with PADUA score ≥8 (p=0.023). After stratification by baseline renal function, ischemia was the only independent factor: no effect on patients with poorer baseline renal function. Patients with baseline SRF 45-55% who did not experience ischemia had the highest probability to maintain ≥90% baseline SRF (p=0.028). Ischemia >25 minutes was detrimental (p=0.017). Conclusions: Stratification of patients by SRF before PN is not a reliable predictor of renal functional outcome. Ischemia seems to scarcely influence patients with poorer renal function.

Clampless laparoscopic partial nephrectomy: a step towards a harmless nephron-sparing surgery?

PURPOSE: To evaluate the results of our technique of clampless laparoscopic partial nephrectomy (LPN) and its impact as an emerging treatment for small renal masses (SMRs). MATERIALS AND METHODS: We reviewed our prospectively maintained database: data of 117 patients who consecutively underwent LPN at our Institution from January 2009 to December 2011 were studied. Patients were divided into 2 Groups based on operative technique: Group A: clampless-LPN (cl-LPN); Group B: conventional LPN (clamping of renal artery). Demographic and peri-operative data, complications, pre- and post-operative serum creatinine and estimated glomerular filtration rate (eGFR) were registered and compared by Student’s t- and Chi-square-tests (p-values < 0.05 considered statistically significant). RESULTS: 41 patients were in Group A and 76 in Group B. Groups were comparable in terms of preoperative data except for tumour’s size (2.35 ± 1.10 vs. 3.19 ± 1.57, Group A vs. B, respectively, p = 0.0029). Concerning perioperative data, warm ischemia time (WIT) was 0 min. in all Group A cases; mean WIT in Group B was 20.90 ± 9.27 min. One case (2.4%) in Group A (central tumour) was converted to conventional LPN. Mean eGFR postoperative decrease was higher in Group B (0.17 ± 9.30 vs. 4.38 ± 11.37 mL/min., A vs B, respectively, p = 0.0445). CONCLUSIONS: Notwithstanding the limits of the study, our results suggest that cl-LPN is a safe and effective technique, which allows surgeon to surgically treat SRMs even in case of complex location, without injuring kidney by ischemia.