The association between the anatomical features of renal tumours and the functional outcomes of robot-assisted partial nephrectomy

Abstract

Introduction: We evaluated the the association between PADUA scores and postoperative renal function (after robot-assisted partial nephrectomy [RAPN]) and between PADUA scores and warm ischemic time (during RAPN). Methods: We reviewed the clinical records of 106 patients who underwent RAPN for a single localized renal tumour between April 2009 and June 2012. Postoperative renal function was evaluated using estimated glomerular filtration rate (EGFR) in 85 patients who were followed for at least 6 months. PADUA scores for renal tumours were calculated using contrast-enhanced computed tomography images, if needed, along with magnetic resonance images in some cases. Results: A PADUA score .10 and WIT .30 minutes were observed in 18 (17.0%) and 51 (48.1%) cases, respectively. PADUA scores were significantly correlated with WIT (p = 0.019) and percent change in EGFR at 6 months postoperatively (p = 0.005). PADUA score (continuous variable, odds ratio [OR] 1.694, p = 0.007) and the high-risk group (PADUA score .10) (OR 5.429; p = 0.020) were significantly associated with a WIT of .30 minutes by multivariate analysis. A 1-point increase in the PADUA score was associated with an EGFR decrease of >20% at 6 months after RAPN (OR 1.799; p = 0.076). In addition, a PADUA score .10, or high risk, (OR 13.965; p = 0.003) was an independent predictor of an EGFR decrease of >20% at 6 months after RAPN. Conclusions: The PADUA classification can reliably predict WIT and postoperative renal functional outcome after RAPN. Furthermore, the study suggests that anatomical aspects of renal tumours are associated with functional outcome after RAPN.