AUA 2018: Renal Function Variability Can Identify Subclinical Kidney Disease Before Nephrectomy

San Francisco, CA USA ( Andrew Sun, MD and his team at Stanford University sought to determine the relationship between the variability in preoperative kidney function and the onset of chronic kidney disease (CKD) and survival rate after partial and radical nephrectomies. As past studies have shown, variability within kidney function has shown to be correlated with more detrimental renal outcomes for patients with CKD. This study further observed the relationship between preoperative variability and overall survival following partial and radical nephrectomies.

To determine the link between the various factors, patients who underwent partial (n=4,082) or radical (n=8,189) nephrectomies from 2002 to 2014 at the Veterans Health Administration (n=18,617) were identified and their clinical and demographic data from electronic medical records was analyzed. Kidney function measurements, such as estimated glomerular filtration rate, were evaluated along all available outpatient kidney function measurements within 12 months prior to their surgery until the end of the study course. Variability was measured by a coefficient of variation.

Patients with more than three preoperative kidney function measurements and an eGFR greater than 30mL/min/1.73 m2 were used in the study with a median number of 5 (IQR 4 to 6) measurements and a median eGFR of 68.8 (IQR 54.2 to 84.6). The mean CV for radical nephrectomy was 0.13 (SD 0.08), while the mean CV for partial nephrectomy was 0.11 (SD 0.07) for partial nephrectomies. Results indicated that the CV was correlated with time to eGFR (HR 1.05, 95%CI + 0.06 after radical; HR 1.24, 95%CI + 0.12 after partial) and overall survival (HR 1.28, 95%CI + 0.13 after radical; HR 1.12, 95%CI + 0.05 after partial).

Dr. Sun concluded that variability within preoperative function may help identify both the onset of CKD and can be associated survival following partial and radical nephrectomies. This study could hopefully present a method to accurately prognose CKD in patients.

Presented by: Andrew Sun, MD

Written by: Sherry Lu, Department of Urology, University of California-Irvine at the 2018 AUA Annual Meeting - May 18 - 21, 2018 – San Francisco, CA USA