Comparison of Measured Renal Tumor Size Versus R.E.N.A.L. Nephrometry Score in Predicting Patient Outcomes After Robot-Assisted Laparoscopic Partial Nephrectomy

Abstract

Partial nephrectomy (PN) is a technically challenging procedure, making selection of appropriate patients paramount to a successful operation. To identify patients at increased risk of an adverse outcome after PN, there are a number of scoring systems available. The nephrometry score was initially described in a series of laparoscopic and open partial and radical nephrectomies. We compare the association of the nephrometry score with perioperative outcomes in a population of robot-assisted partial nephrectomies. A total of 119 patients were retrospectively reviewed. Correlation and regressional analysis was performed. We identified the separate variables R, E, N, and L to have limited correlation and no predictive value to patient outcomes. Nephrometry score and grade were found to have stronger correlation and predictive value than the individual components of the R.E.N.A.L. nephrometry score. Size of tumor measured on a continuous scale was found to have the strongest correlation and predictive value to outcomes. Outcomes predicted included operative time, length of stay, warm ischemia time, and entry into the collecting system.