Comparison of Robot-Assisted and Laparoscopic Partial Nephrectomy for Completely Endophytic Renal Tumors: A High-Volume Center Experience

Objectives: To compare the perioperative, functional, and oncologic outcomes of robot-assisted partial nephrectomy (RAPN) and laparoscopic partial nephrectomy (LPN) for completely endophytic renal tumors (three points for the "E" element of the R.E.N.A.L. scoring system). Materials and Methods: We retrospectively reviewed patients who underwent either RAPN or LPN between 2013 and 2016. Baseline characteristics, perioperative, functional, and oncologic outcomes were compared. Univariable and multivariable logistic analyses were performed to determine factors associated with pentafecta achievement (ischemia time ≤25 minutes, negative margin, no perioperative complication, return of estimated glomerular filtration rate [eGFR] to >90% from baseline, and no chronic kidney disease upstaging). Results: No significant differences between RAPN vs LPN were noted for operating time (105 minutes vs 108 minutes, p = 0.916), estimated blood loss (50 mL vs 50 mL, p = 0.130), renal artery clamping time (20 minutes vs 20 minutes, p = 0.695), rate of positive margins (3.3% vs 2.0%, p = 1.000), and postoperative complication rates (18.0% vs 21.6%, p = 0.639). RAPN was associated with a higher direct cost ($11240 vs $5053, p < 0.001). There were no significant differences in pathology variables, rate of eGFR decline for postoperative 12-month (9.8% vs 10.6%, p = 0.901) functional follow-up. Multivariate analysis identified that only RENAL score was independently associated with the pentafecta achievement. Conclusions: For completely endophytic renal tumors, both RAPN and LPN have excellent and similar results. Both operation techniques remain viable options in the management of these cases.