PD37-10: Comparative Analysis of Functional Outcomes of Open, Laparoscopic and Robotic Partial Nephrectomy Stratified by Tumor Complexity: A Multi-Center Study

Ava Saidian*, Arman Walia, Juan Javier-Desloges, Ithaar Derweesh, La Jolla, CA

Introduction: Partial nephrectomy (PN) for localized renal masses has become standard of care, though impact of surgical approach [open (OPN) vs. laparoscopic (LPN) vs. robotic (RPN)] as it relates to tumor complexity remains controversial. We sought to evaluate the impact of RENAL score and surgical approach on functional outcomes.

Methods: Multi-institutional retrospective analysis of PN performed between 2000-2016. The cohort was divided into OPN vs. LPN vs. RPN approach, and descriptive analyses were conducted. Primary outcome was developed of new onset CKD (defined as eGFR <45 mL/min/1.73m2). multivariable binary logistic regression (MVA) was performed to identify predictors of de novo CKD. Multivariable linear regression was conducted for delta eGFR (?eGFR ) comparing OPN vs. LPN vs. RPN approaches based on RENAL score category.

Results: 3,525 patients were included: 1,465 (41.56%) underwent OPN, 536 (15.21%) had LPN, and 1524 (43.23%) underwent RPN. Multivariable binary logistic regression assessing predictors of de novo CDK <45 stratified by RENAL score group found that in the low complexity group: increasing age (OR 1.059, p=0.013) was positively associated, while increasing preoperative eGFR (OR 0.932, p<0.001), and RPN (OR 0.36, p=0.032) were negatively associated. In the intermediate complexity group: increasing BMI (OR 1.079, p=0.053) was positively associated, while increasing preoperative eGFR (OR 0.881, p<0.001) was negatively associated with de novo CKD. For the high complexity group: only increasing preoperative eGFR was negatively associated (OR 0.866, p=0.022). Multivariable linear regression assessing predictors of ?eGFR by RENAL score category found for low complexity tumors: age (B -0.124, p<.001), preoperative eGFR (B -0.386, p<0.001), diabetes (DM, B -4.681, p<0.001) were associated with a larger decrease in ?eGFR. In intermediate complexity tumors: age (B -0.114, p=0.004), preoperative eGFR (B -0.398, p<0.001), DM (B -5.783, p<0.001), BMI (B -0.238, p=0.013) are associated with larger  ?eGFR, while robotic approach (B 2.391, p=0.013) is associated with smaller ?eGFR. In high complexity tumors: age (B -0.296, p=0.17) and preoperative eGFR (B -0.433, p<0.001) were associated with larger ?eGFR.

Conclusions: RPN is not associated with worsened renal functional outcomes, even amongst high RENAL score complexity tumors. In experienced hands, RPN may be considered as a viable option in patients with increasingly complex masses in whom preservation of renal function is imperative and where functional reserve may be limited.

Source of Funding: N/A