Predicting Renal Parenchymal Loss after Nephron Sparing Surgery

Area of Science:

• Urology
• Nephrology
• Surgical Oncology

Background:

• Nephron sparing surgery (NSS) is a standard treatment for localized renal masses.
• Assessing post-operative renal parenchymal volume loss is crucial for understanding functional outcomes.
• Novel 3-dimensional (3D) volumetric assessment offers precise measurement of renal volume changes.

Purpose of the Study:

• To identify patient, operative, and tumor characteristics associated with renal parenchymal volume loss after NSS.
• To utilize 3D volumetric analysis for precise quantification of renal volume changes post-surgery.
• To determine key predictors of renal parenchymal volume loss following NSS.

Main Methods:

• Retrospective review of 158 patients undergoing NSS for localized renal masses (1992-2014).
• Tumor classification using the R.E.N.A.L. nephrometry system.
• Pre- and post-operative renal parenchymal volume calculated using 3D reconstruction imaging software.

Main Results:

• Mean renal parenchymal volume loss was -15.3% for the ipsilateral kidney and -6.8% for total kidney volume.
• Univariate analysis showed associations between volume loss and ischemia time, tumor size, R.E.N.A.L. score, and specific nephrometry components.
• Multivariate analysis identified ischemia time, tumor size, posterior location, and exophytic properties as independent predictors of greater volume loss.

Conclusions:

• Precise 3D volumetric analysis reveals significant renal parenchymal volume loss after NSS.
• Ischemia time, tumor size, and endophytic/exophytic properties are key determinants of renal parenchymal volume loss.
• These findings aid in predicting and potentially mitigating renal volume loss during NSS for localized renal masses.