Usefulness of R.E.N.A.L Nephrometry Scoring System and Centrality Index Score for Predicting Outcome of Laparoscopic Partial Nephrectomy.

OBJECTIVES: The aim of this study was to investigate the clinical usefulness for prediction of outcome of laparoscopic partial nephrectomy (LPN) using the R.E.N.A.L nephrometry scoring system (RNS) and centrality index score (C-index).

MATERIALS AND METHODS: We retrospectively reviewed 64 patients who underwent LPN from 2010 to 2014 in our institution. The RNS and C-index scores were assigned according to the described protocols for their systems. The relationships between the patients' scores before surgery and the outcomes of LPN, warm ischemia time (WIT), operative time (ORT), estimated blood loss (EBL), and percent change in estimated glomerular filtration rate (eGFR) were analyzed retrospectively.

RESULTS: Mean tumor size was 3.1 cm, mean WIT was 27.6 minutes, mean ORT was 189.0 minutes, and mean EBL was 187 mL. Although the RNS had statistically significant correlations with WIT, ORT, and percent change in eGFR, these correlations were not score-dependent. For WIT, a statistically significant difference was observed between the low-risk group and the middle-risk group. For percent change in eGFR, a statistically significant difference was observed between the low-risk group and the high-risk group only. For the C-index, statistically significant correlations between complexity categories and WIT, ORT, EBL, and percent change in eGFR were observed. Regarding the raw C-index scores, linear correlations were observed between the scores and each outcome of LPN.

CONCLUSIONS: The RNS and C-index are useful for predicting the complexity of LPN. The C-index may be more suitable than the RNS for predicting postoperative renal function.