The incidence of unsuccessful partial nephrectomy within the United States: A nationwide population-based analysis from 2003 to 2015.

Purpose: Partial nephrectomy (PN) remains underutilized within the United States and few reports have attempted to explain this trend. The aim of this study is to evaluate the nationwide incidence of unsuccessful PN and factors that predict its occurrence.

Methods: Using the Premier Healthcare Database, we retrospectively analyzed a weighted sample of 66,432 patients undergoing curative surgery for renal mass between 2003 and 2015. PN intent was denoted by presence of insurance claims for the administration of mannitol. Unsuccessful PN was defined as an event in which patients were administered mannitol but received radical nephrectomy. A multivariate logistic regression model was generated to identify factors predicting unsuccessful PN.

Results: Overall rates of unsuccessful PN declined from 33.5% to 14.5% since 2003. Conversion to radical nephrectomy occurred most frequently during laparoscopic (34.7%) and least frequently during robotic approach (13.6%). There was significant difference in the rate of unsuccessful PN between very high and very low volume surgeons (open: 39.4% vs. 13.3%, laparoscopic: 51.2% vs. 32.2%, and robot assisted: 27.1% vs. 9.4%, all P<0.001). After adjustment for patient- and hospital-related factors, surgical approach (laparoscopic vs. open, odds ratio = 1.74, 95% CI: 1.31-2.30, P<0.001) and annual surgeon volume (very high vs. very low, odds ratio = 0.27, 95% CI: 0.21-0.34 P<0.001) were associated with unsuccessful PN.

Conclusions: Although the rate of unsuccessful PN appears to be declining, it still remains common for low volume surgeons and with the laparoscopic surgical approach. Further evaluation of its effect on health care outcomes is necessary.