Comparison of Differential Functional Outcomes After Partial Nephrectomy Between Moderate and High Complex Renal Tumor Evaluated with Diethylenetriamine Pentaacetic Acid Scan: A Propensity Score Matched Analysis

Objective The aim of this study was to compare functional outcomes after partial nephrectomy (PN) between moderate and high complex renal tumors evaluated with a diethylenetriamine pentaacetic acid (DTPA) scan [moderate vs. high: RENAL nephrometry score (RNS) 7-9 vs. 10-12]. Methods From January 2004 to December 2019, 471 patients with an RNS of 7-9 (moderate) and 164 patients with an RNS of 10-12 (high) who underwent PN were analyzed for renal function outcomes. The glomerular filtration rate (GFR) was measured using a DTPA scan and calculated the GFR using the Modification of Diet in Renal Disease (MDRD) formula, respectively. Trifecta/pentafecta outcome, recurrence-free survival, and overall survival were compared after propensity score matched analysis (PSMA). Results After PSMA, 156 cases in each group were matched without significant difference in the preoperative factor. At the postoperative first year, there was no significant difference in the trifecta (p = 0.320), MDRD-based (p = 0.729), or DTPA-based pentafecta achievement rate (p = 0.964) between groups. At postoperative 5 years, DTPA-based total GFR (93.6% vs. 93.8%) and the operated kidney GFR preservation rate (89.9% vs. 81.7%) did not differ significantly (p > 0.05). Kaplan-Meier survival analysis showed no significant differences in survival outcomes (p > 0.05). Significant predictors of de novo chronic kidney disease (CKD) stage 3 or higher at the postoperative first year were age [hazard ratio (HR) 1.10, 95% confidence interval (CI) 1.03-1.17, p = 0.005] and preoperative DTPA-based total GFR (HR 0.94, 95% CI 0.91-0.98, p = 0.001). Conclusion High complex tumors can be treated with PN without significant deterioration in renal function. The postoperative function of the operated kidney was preserved by up to 80% in the long term compared with the preoperative period. However, PN should be selectively performed with caution to avoid the occurrence of postoperative CKD.