Computed tomography based renal parenchyma volume measurements prior to renal tumor surgery are predictive of postoperative renal function.

ABSTRACT

INTRODUCTION: To determine whether preoperative computed tomography (CT) based renal parenchymal volume (RPV) measurements would be predictive of postoperative chronic kidney disease (CKD). MATERIALS AND METHODS: From 2005 to 2010, 189 patients with preoperative CT imaging performed at Emory University Hospital underwent renal tumor surgery. Preoperative and postoperative renal function was determined by estimating glomerular filtration rate (GFR) using standard Cockcroft-Gault (CG) and Modification of Diet in Renal Disease (MDRD) equations. Preoperative CT measured RPV was calculated to determine association of predicted preserved renal parenchyma with postoperative renal function and the development of CKD (GFR < 60 mL/min/1.73 m2). RESULTS: For the entire cohort, radical nephrectomy (RN), lower preoperative GFR, and volume of kidney without tumor were associated with the development of CKD (p = < 0.05). If the non-tumor bearing kidney constituted ≥ 50% of the total bilateral preoperative RPV, then risks of developing CKD were decreased. In patients treated with partial nephrectomy (PN) or ablation, total bilateral preoperative RPV measurements predicted postoperative renal function (CKD ≥ 3 versus CKD < 3) to a significant degree (p < 0.001). CONCLUSIONS: Preoperative CT based RPV measurements are independently associated with the development of CKD in patients undergoing renal tumor surgery. This provides urologists with another tool in the assessment of patients with renal tumors.