Preoperative Age and Its Impact on Long-Term Renal Functional Decline after Robotic-Assisted Partial Nephrectomy: Insights from a Tertiary Referral Center

Abstract

Background and Objectives: to investigate the impact of age on renal function deterioration after robotic-assisted partial nephrectomy (RAPN) focusing on a decline to moderate and severe forms of chronic kidney disease (CKD). Materials and Methods: This is a single center prospective analysis of patients who underwent RAPN. The outcomes include the development of de novo CKD-S 3a [estimated glomerular filtration rate (eGFR) < 60 mL/min/1.73 m²)] and de novo CKD-S 3b (eGFR < 45 mL/min/1.73/m²). Multivariable analysis (MVA) via Cox regression identified predictors for CKD-S 3a/b. Kaplan -Meier Analyses (KMA) were fitted for survival assessment. Multivariable linear regression was utilized to identify the predictors of last-eGFR. Results: Overall, 258 patients were analyzed [low age (<50) n = 40 (15.5%); intermediate age (50-70) n = 164 (63.5%); high age (>70) n = 54 (20.9%)] with a median follow-up of 31 (IQR 20-42) months. MVA revealed an increasing RENAL score [Hazard Ratio (HR) 1.32, p = 0.009], age 50-70 (HR 6.21, p = 0.01), age ≥ 70 (HR 10.81, p = 0.001), increasing BMI (HR 1.11, p < 0.001) and preoperative CKD 2 (HR 2.43, p = 0.014) are independent risk factors associated with an increased risk of CKD-S 3a; conversely, post-surgical acute kidney injury was not (p = 0.83). MVA for CKD-S 3b revealed an increasing RENAL score (HR 1.51, p = 0.013) and age ≥ 70 (HR 2.73, p = 0.046) are associated with an increased risk of CKD-S 3b. Linear regression analysis revealed increasing age (Coeff. -0.76, p < 0.001), increasing tumor size (Coeff. -0.31, p = 0.03), and increasing BMI (Coeff. -0.64, p = 0.004) are associated with decreasing eGFR at last follow-up. We compare the survival distribution of our cohort stratified by age elderly patients experienced worsened CKD-S 3a/b disease-free survival (p < 0.001; p < 0.001, respectively). Conclusions: Age is independently associated with a greater risk of significant and ongoing decline in kidney function following RAPN. Recognizing the impact of aging on renal function post-surgery can guide better management practices. Further investigations are required.

Keywords: CKD-S; age; estimated glomerular filtration rate; functional decline; nephrectomy; renal cell carcinoma; robotic surgery; survival analysis.