ADOPTION, COST, AND THE ECONLY OF SCALE OF ROBOTIC VERSUS LAPAROSCOPIC RADICAL NEPHRECTOMY PROCEDURES.

Robotic-assisted laparoscopic surgery has become ubiquitous in most surgical disciplines. However, robotic surgery has seldom demonstrated a cost or outcome advantage versus pure laparoscopy over a diverse array of procedures. Robotic radical nephrectomy was previously shown to be more expensive than its laparoscopic counterpart, with similar complication rates and no clear oncologic advantage. Initial acquisition of robotic technology confers a significant fixed expense, and therefore, early proponents of robotic surgery posited that increased adoption should contribute to decreased marginal cost. While such economies of scale have been described in certain health services, no such effect has been demonstrated in robotic surgery. Here, we explore patterns of robotic adoption, and address whether increasing volume of robotic radical nephrectomy procedures provides a cost advantage relative to the laparoscopic approach. We analyzed patients (n=60,001) within the Premier Healthcare Database who underwent nephrectomy between 2010 and 2019. Patients who underwent partial nephrectomy, nephroureterectomy, or donor nephrectomy were excluded from the analysis. Robotic, laparoscopic, and open approaches to radical nephrectomy were identified from billing information. The primary outcome was total hospital costs of index admissions, adjusted to 2019 United States dollars using the consumer price index, amongst patients undergoing robotic versus laparoscopic radical nephrectomy. Patient and hospital characteristics were tabulated by surgical approach, and inverse probability treatment weighting was performed to compare costs between robotic and laparoscopic approaches. The mean annual change in total cost by surgical approach was estimated, and generalized linear regression models determined the difference in cost between robotic and laparoscopic procedures;as a function of treatment year or as a function of time since first adoption of robotic radical nephrectomy. 39,305 patients were included for analysis. Mean age was 62.2 years (SD;12.9), and 23,191 (59%) patients were men. 5,288, 11,908, and 22,109 patients underwent robotic, laparoscopic, and open radical nephrectomy, respectively. Proportional utilization of the robotic approach increased from 2.9% (111/3799 procedures) in 2010 to 31% (954/3072 procedures) in 2019 (Figure). Adjusted mean total costs were $18,922, $15,357, and $18,538;for the robotic, laparoscopic, and open approaches, respectively. Mean adjusted total costs of the robotic and laparoscopic approaches stratified by year of treatment or years since first robotic adoption are shown in the Table. The mean annual differences in adjusted total costs between robotic and laparoscopic approaches decreased over time based on year of treatment (-$1.26 [95% CI -408, 405], p=0.9) and years since robotic adoption (-$63 [95% CI -454, 328], p=0.8), but the differences were not statistically significant. Among patients undergoing radical nephrectomy between 2010 and 2019, the proportion of surgeries performed via the robotic approach increased relative to the proportion of laparoscopic or open procedures. While total costs decreased slightly over time for both robotic and laparoscopic techniques, there was no substantial decrease in the cost of robotic procedures relative to laparoscopic cases and suggests an "economy of scale" has yet to be achieved among hospitals performing robotic radical nephrectomies. More work is needed to validate the cost-effectiveness and long-term sustainability of performing robotic radical nephrectomies over purely laparoscopic techniques. [ABSTRACT FROM AUTHOR]