Association Of Robotic Partial Nephrectomy For Clinical T2a Renal Mass With Improved Trifecta Outcome Compared To Open Partial Nephrectomy: A Single Surgeon Comparative Analysis

653 Background: We compared surgical quality and functional outcomes of robotic partial nephrectomy (RPN) and open PN (OPN) for cT2a renal masses (cT2aRM). Methods: Retrospective analysis of 150 consecutive patients [RPN 59/OPN 91] from 6/2008 to 6/2016. Main outcome was achievement of Trifecta [negative surgical margin, no major urologic complications, and ≥90% preservation of estimated glomerular filtration rate (eGFR)]. Multivariable analysis was performed to identify factors of Trifecta attainment. Results: Mean tumor size (RPN 7.9 vs. OPN 8.4 cm, p=0.139) and median RENAL score (p=0.361) were similar. No difference was noted for positive margins (RPN 3.4% vs. OPN 1.1%, p=0.561), DeGFR (RPN -6.2 vs. OPN -7.8, p=0.543), and ≥90% eGFR recovery (RPN 54.1% vs. OPN 47.2%, p=0.504). RPN had lower blood loss (p=0.015), hospital stay (p=0.013), and Clavien ≥3 complications (RPN 5.1% vs. OPN 16.5%, p=0.041). Trifecta rate was significantly higher in RPN (47.5% vs. 34.0%, p=0.041). Multivariable analysis demonstrated decreasing RENAL score (OR 1.11, p<0.001), RPN (OR 1.2, p=0.013), and decreasing EBL (OR 1.02, p=0.016) to be associated with Trifecta attainment. Conclusions: RPN provided similar functional and oncologic precision to OPN, while being associated with improvements in major complications, the latter of which was reflected in a higher rate of Trifecta achievement for RPN. RPN may be considered to be a first-line option for select patients with cT2aRM when feasible and safe.