Association of tumor size, location, R.E.N.A.L., PADUA and centrality index score with perioperative outcomes and postoperative renal function

Purpose: Multiple scoring systems have been proposed to standardize the description of anatomical features of renal tumors. However, it remains unclear which of these systems, if any, is most useful, or whether any performs better than simply reporting tumor size or location in patients undergoing partial nephrectomy. To clarify these issues we evaluated the association of tumor size, location, R.E.N.A.L. (Radius/Exophytic/Nearness to collecting system/Anterior/Location), PADUA (Preoperative Aspects and Dimensions Used for an Anatomical classification) and centrality index scores with perioperative outcomes. Materials and Methods: Patients undergoing partial nephrectomy with available preoperative imaging were identified from 2005 to 2011. R.E.N.A.L., PADUA and centrality index scores were assigned according to the described protocols for those systems. Associations between each variable and ischemia time, estimated blood loss, total operative time and change in estimated glomerular filtration rate were examined. Results: A total of 162 patients were identified with a median tumor size of 3.1 cm (IQR 2.2 to 4.6). Median estimated blood loss, ischemia time and total operative time were 200 ml (IQR 100 to 300), 24 minutes (IQR 20 to 30) and 211 minutes (IQR 179 to 249), respectively. Each scoring system was found to have a statistically significant (p <0.001) correlation with ischemia time, with the centrality index system showing the strongest correlation. Furthermore, each of the scoring systems showed a stronger correlation with ischemia time than tumor size or tumor location. Conclusions: Each scoring system outperformed tumor size and location, and may be useful when describing the surgical complexity of renal tumors treated with partial nephrectomy.