Morphometric profile of the localised renal tumors managed either by open or robot-assisted nephron-sparing surgery: the impact of scoring systems on the decision making process

Abstract

Background: Nephrometric scoring systems aim to improve the manner in which tumoral complexity is measured and reported. Each system provides a way to objectively measure specific tumor features that influence technical feasibility. In this study we aimed to determine how nephrometric scoring systems tailored our approach to the surgical treatment of localised renal masses. Methods: Charts of the patients with localised renal tumors, who were managed by either open or robot-assisted nephron-sparing surgery between May 2010 and June 2012, were retrospectively reviewed. Nephrometric scores [radius, exophytic/endophytic, nearness, anterior/posterior, location (R.E.N.A.L.) score, preoperative aspects and dimensions used for anatomic (P.A.D.U.A.) classification and centrality index (C-index)] were calculated based on preoperative imaging findings. Perioperative data were recorded. Morphometric characteristics of the renal masses were compared. Additionally, the difference between surgical alternative subgroups in terms of morphometric variables and the predictive power of each scoring system in determining the details of the surgical plan were investigated. Furthermore, surgical preferences in different nephrometric categories were compared. Results: Mean R.E.N.A.L. and P.A.D.U.A. scores of the tumors treated with robotic surgery were significantly lower than those managed by open surgery. R.E.N.A.L. nephrometry score showed significant differences between most of the surgical alternative subgroups. P.A.D.U.A. and C-index differences were significant only between robotic off-clamp and open clamped cases. Tumors that required open conversion had significantly higher mean R.E.N.A.L. and P.A.D.U.A. score. High R.E.N.A.L. score (cut-off: 6.5) and high P.A.D.U.A. score (cut-off: 7.5) were found to be significant predictors of the surgical route. Significantly more tumors with moderate R.E.N.A.L. score were managed through the open approach, while the significant majority of those with low R.E.N.A.L. and low P.A.D.U.A. score were operated by robotic assistance. Conclusions: R.E.N.A.L. and P.A.D.U.A. scores influenced our surgical treatment strategy for localized renal masses. High R.E.N.A.L. and P.A.D.U.A. scores increased the likelihood of an open NSS.