Trends in the surgical management of localized renal masses: thermal ablation, partial and radical nephrectomy in the USA, 1998-2008

What's known on the subject? and What does the study add? Treatment options for small renal masses include radical nephrectomy (RN), and nephron sparing modalities (NSM) such as partial nephrectomy (PN), and thermal ablation (Cryo- and radiofrequency ablation, C/RFA). Prior studies had demonstrated gross underutilization of PN; however overall treatment trends for C/RFA had not been well studied using a population-based cohort. In this study, which examined management trends of localized renal masses in the USA, we identified an increased prevalence of RN, PN and C/RFA over the study period, with PN increasing the most rapidly, and with RN continuing to account for the vast majority of procedures. This is the first study to examine surgical management of renal masses in patients with non-dialysis dependent chronic renal insufficiency. Although nephron sparing modalities were increasingly utilized over the study period, it is particularly concerning that patients with pre-existing non-dialysis dependent chronic renal insufficiency are receiving less nephron sparing approaches. Further investigations are required to confirm these findings and to identify impediments to the dissemination of nephron sparing modalities. Objective To evaluate the diffusion of nephron-sparing modalities (NSM) for the treatment of renal neoplasms in the USA over the last decade and to identify the factors associated with renal procedure selection. Patients and Methods The Nationwide Inpatient Sample was utlized to identify patients undergoing cryo/radiofrequency ablation (C/RFA), radical nephrectomy (RN) and partial nephrectomy (PN) from 1998 to 2008. Annual trends in procedure prevalence were determined. Multivariate analyses were performed to query the influence of age, race, sex and comorbid disease on surgery selection. Results We identified 443853 procedures performed during the study period: 25599 C/RFA, 79568PN and 338687 RN. The prevalence per 100000 hospital admissions in 1998 was 3.7 for C/RFA, nine for PN and 87.1 for RN. All procedures increased over the study period, by 1.05, 3.1 and 2.2/100000 admissions per year, respectively (all P < 0.001). Diabetes, urban, teaching and large capacity hospitals were associated with NSM (either C/RFA or PN) compared to RN (all P 0.011). Age 70 years, female, hypertension, diabetes, chronic kidney disease (CKD) and region outside the Northeast favoured C/RFA over PN (all P 0.026). Compared to those without CKD, patients with CKD had an almost twofold higher probability of undergoing RN than NSM (odds ratio, 1.88; 95% confidence interval, 1.7-2.1). Despite increasing NSM utilization over the study period, most patients with CKD still received RN. Conclusions Although the prevalence of NSM is increasing, RN is more common. The low utilization of NSM in patients with pre-existing CKD warrants further investigation.