Contemporary Analysis of Calculous Nephrectomy Utilization and Outcomes in the United States

Abstract

Introduction: Calculous nephrectomy was a mainstay of treatment of complex upper tract stone disease up until the 1970s, but data on its contemporary utilization in the current era of rising rates of stone disease are lacking. We characterized the nationwide utilization and outcomes for calculous nephrectomy in the United States. Patients and Methods: The National/Nationwide Inpatient Sample databases for 2001 to 2014 were queried for adults with a principal diagnosis of upper urinary tract calculi (UUTCs), who underwent nephrectomy as well as other inpatient surgeries for UUTCs. Per-population trend in utilization of calculous nephrectomy was analyzed using negative binomial regression. The proportion of calculous nephrectomy as a fraction of all inpatient surgical procedures for UUTCs was analyzed using the Cochran-Armitage test. Patient demographics, hospital characteristics, perioperative outcomes, and complications were analyzed using appropriate statistical tests. Results: Of almost 1.42 million inpatient UUTC procedures performed over the study period, 9232 (0.65%) were calculous nephrectomies. Per-population utilization rate for calculous nephrectomy decreased significantly over time (incidence rate ratio = 0.82; 95% confidence interval = 0.73-0.91, p < 0.001). The proportion of calculous nephrectomy as a fraction of all inpatient surgical procedures for UUTC also decreased significantly over time (p < 0.0001). Majority of the procedures were performed in females, in urban teaching hospitals, and in the Southern United States. The overall complication rate was 38.3%, most commonly hemorrhage requiring transfusion (15.6%). Older age, female gender, and nonprivate insurance or lack of insurance were significant predictors of increased risk of complications, whereas hospitalization in urban hospitals was a predictor of lower risk. Conclusions: Despite increasing prevalence of stone disease in the United States in the contemporary era, utilization of calculous nephrectomy is low and is declining. Inpatient complication rates are moderately high and influenced by patient sociodemographic and hospital characteristics.

Keywords: kidney calculi; nephrectomy; treatment outcome.