Functional outcomes following robotic-assisted versus laparoscopic partial nephrectomy: The role of ischemia, tumor complexity, and surgical technique in renal function preservation

This study evaluated renal function variation over 12 months after partial nephrectomy (PN), assessing the influence of ischemia strategy, nephrometry scores, surgical technique, and baseline patient characteristics. From January 2020 to December 2024, 62 patients underwent video-laparoscopic PN and 46 underwent robot-assisted PN (RaPN). Serum creatinine and estimated glomerular filtration rate (eGFR) were measured at baseline, immediately and at 1, 3, 6, and 12 months after surgery. Tumor complexity was evaluated using PADUA (preoperative aspects and dimensions used for an anatomical classification) and RENAL (radius, exophytic/endophytic preoperaties nearness to copllecting system or sinus, anterior/posterior location and location) scores. Analyses compared on-clamp and off-clamp procedures and the two surgical approaches. Pure enucleation procedures without renorrhaphy were quantified. Hypertension was recorded as a binary variable and analyzed as a predictor of renal function decline. Statistical methods included t -test, Wilcoxon and Mann–Whitney U tests, Fisher's exact test, Spearman's correlation, and multivariable linear regression. Renal function showed an initial postoperative decline with gradual recovery and stabilization within 12 months. RaPN was associated with significantly better eGFR preservation than video-laparoscopic PN ( p =0.001). Off-clamp procedures showed better functional outcomes, particularly in RaPN. A significant inverse correlation between nephrometry scores and eGFR variation was seen only in the robotic group. Absence of renorrhaphy was more frequent in robotic off-clamp procedures ( p <0.01) and in laparoscopic on-clamp surgeries ( p =0.001). No significant difference was observed in renorrhaphy absence in the off-clamp subgroup ( p= 0.4, odds ratio 0.72). Hypertension was the only patient factor significantly associated with long-term eGFR decline ( p =0.035). Robot-assisted and off-clamp PN showed superior functional preservation, especially in complex tumors. Absence of renorrhaphy was more frequent in robotic off-clamp cases, suggesting a possible link to better renal outcomes. Future studies should explore the role of residual vascularized renal parenchyma to identify ideal candidates for off-clamp surgery.