Comparison of Renal Function between Robot-Assisted and Open Partial Nephrectomy as Determined by Tc 99m-DTPA Renal Scintigraphy

We compared postoperative renal function impairment between patients undergoing robot-assisted partial nephrectomy (RAPN) and those undergoing open partial nephrectomy (OPN) by using Tc-99m diethylenetriaminepentaacetic acid (DTPA) renal scintigraphy. Patients who underwent partial nephrectomy by a single surgeon between 2007 and 2013 were eligible and were matched by propensity score, based on age, tumor size, exophytic properties of tumor, and location relative to the polar lines. Of the 403 patients who underwent partial nephrectomy, 114 (28%) underwent RAPN and 289 (72%) underwent OPN. Mean follow-up duration was 35.2 months. Following propensity matching, there were no significant differences between the two groups in tumor exophytic properties (P = 0.818) or nephrometry score (P = 0.527). Renal ischemic time (24.4 minutes vs. 17.8 minutes, P < 0.001) was significantly longer in the RAPN group than in the OPN group, while the other characteristics were similar. Multivariate analysis showed that greater preoperative renal unit function (P = 0.011) and nephrometry score (P = 0.041) were independently correlated with a reduction in glomerular filtration rate. The operative method did not correlate with renal function impairment (P = 0.704). Postoperative renal function impairment was similar between patients who underwent OPN and those who underwent RAPN, despite RAPN having a longer ischemic time.