[Ischemia is not an independent predictive factor of chronic renal failure after partial nephrectomy in a solitary kidney in patients without pre-operative renal insufficiency]. / L'ischémie a un impact limité sur la fonction rénale après néphrectomie partielle sur rein unique chez les patients sans insuffisance rénale préopératoire.

OBJECTIVE: To assess the influence of vascular clamping and ischemia time on long-term post-operative renal function following partial nephrectomy (PN) for cancer in a solitary kidney. PATIENTS AND METHODS: This is a retrospective study including 259 patients managed by PN between 1979 and 2010 in 13 centers. Clamping use, technique choice (pedicular or parenchymal clamping), ischemia time, and peri-operative data were collected. Pre-operative and last follow-up glomerular filtration rates were compared. A multivariate analysis using a Cox model was performed to assess the impact of ischemia on post-operative chronic renal failure risk. RESULTS: Mean tumor size was 4.0±2.3cm and mean pre-operative glomerular filtration rate was 60.8±18.9mL/min. One hundred and six patients were managed with warm ischemia (40.9%) and 53 patients with cold ischemia (20.5%). Thirty patients (11.6%) have had a chronic kidney disease. In multivariate analysis, neither vascular clamping (P=0.44) nor warm ischemia time (P=0.1) were associated with a pejorative evolution of renal function. Pre-operative glomerular filtration rate (P<0.0001) and blood loss volume (P=0.02) were significant independent predictive factors of long-term renal failure. CONCLUSION: Renal function following PN in a solitary kidney seems to depend on non-reversible factors such as pre-operative glomerular filtration rate. Our findings minimize the role of vascular clamping and ischemia time, which were not significantly associated with chronic renal failure risk in our study. LEVEL OF EVIDENCE: 5.

Predictive factors of chronic kidney disease stage V after partial nephrectomy in a solitary kidney: a multi-institutional study.

OBJECTIVE: Partial Nephrectomy (PN) in a solitary kidney is at risk of chronic kidney disease (CKD) stage V and/or haemodialysis (HD). Our objective was to determine predictive factors of CKD stage V in this population. MATERIAL & METHODS: Data from 300 patients were retrospectively collected from 16 tertiary centres. Clinical and operative parameters, tumor characteristics and renal function before surgery were analyzed. Patients with and without CKD stage V (defined as MDRD<1 5 ml/min) were compared using χ2 and Student-t tests for qualitative and quantitative variables, respectively. Predictive factors of CKD stage V were evaluated with a multivariable analysis using a Cox regression model. RESULTS: Median age and BMI were 63 years old and 26 kg/m², respectively. Most of the patients (65%) were male with an anatomic solitary kidney (88.3%). Median tumor size was 4 cm and 98% were malignant tumors. Median operative time, blood loss and clamping time were 180 min, 350 ml and 20 min respectively. Renal cooling was used in 19.3% and clamping of the pedicle was performed in 61.6%. Twenty five patients (8.5%) presented post operative CKD stage V at last follow-up and 18 underwent HD (6%) post-operatively because of acute renal insufficiency. There was no difference between CKD stage V and non CKD stage V patients concerning Charlson index, operative time (180 min vs 179 min, p = 0.39), blood loss (475 ml vs 350 ml, p = 0.51), use of renal cooling and type of clamping. Patients with CKD stage V were older (70 vs 63 years old, p = 0.005), had a lower baseline renal function (clearance MDRD 41 vs. 62 ml/min, p<0.0001) and an increased tumor size (p = 0.02). Complications occurred in 91 patients (30%) with 16% of minor (Clavien 1-2) and 14% of major (Clavien > 2) complications, respectively. In multivariable analysis, baseline MDRD, BMI, and the occurrence of a minor complication were independent predictive factors of post operative CKD stage V. CONCLUSION: PN in a solitary kidney is at risk of post-operative CKD stage V and HD. Pre-operative altered renal function and post operative complications are the main predictive factors of permanent CKD stage V.