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.

Acute kidney injury after nephron sparing surgery and microwave ablation: focus on incidence, survival impact and prediction

“…Bertolo et al confirmed worse probability of maintaining !90% baseline renal function was found more in patients with CCI ! 3 (p ¼ 0.004) and patients with PADUA score !8 (p ¼ 0.023) [40]. Casey and Inderbir et al indicated that, for medially based hilar tumors which are higher RENAL nephrometry scores, robotassisted and laparoscopic partial nephrectomies are virtually impossible if the hilum remains unclamped, because one or more distinct, higher-order arteries immediately supply the tumor or tumor-bearing segment of the kidney [41].…”

Partial laparoscopic nephrectomy: what really matters?

“…Although the reported significantly higher ΔeGFR (mL/min/1.73m2) in the transperitoneal access (10) should be analyzed with care and further explored in future studies, >90% of baseline function maintenance was the rule as expected, considering the off-clamp tactic (12). On the other hand, data is limited to serum creatinine levels and subject to variations on estimated glomerular filtration rate (eGFR) in a low volume surgeon scenario (13).…”

Editorial Comment: Role of preoperative MR volumetry in patients with renal cell carcinoma for prediction of postoperative renal function after radical nephrectomy and nephron sparing surgery

“…The MRI volumetry was used to estimate the renal parenchymal volume and shows that preoperative residual parenchymal volume on MRI renal volumetry correlates well with postoperative GFR in patients with RCC undergoing radical nephrectomy or nephron sparing surgery. Partial nephrectomy (open, laparoscopic or robotic) is considered the gold standard for treating localized renal tumors ( 2 - 6 ). Renal parenchymal preservation is the great objective of the partial nephrectomy.…”