Unplanned Conversion from Minimally Invasive to Open Kidney Surgery: The Impact of Robotics.

Unplanned conversion from minimally invasive surgery (MIS) to open surgery is a significant challenge, although the frequency of conversion for robotic and laparoscopic kidney surgery is not well described. We aimed to compare rates of conversion for robotic versus laparoscopic kidney surgery. The National Cancer Database was used to identify patients who underwent robotic or laparoscopic partial nephrectomy (PN), radical nephrectomy (RN), or nephroureterectomy (NU) from 2010 to 2014. Multivariate logistic regression was used to identify factors associated with conversion to open. Length of stay and 30-day mortality rate were compared between groups using Kruskal-Wallis and Fisher's exact tests. Propensity score matching was performed to confirm study results. A total of 61,191 patients underwent MIS PN, RN, or NU. Conversion rates were lower for robotics than for laparoscopy (PN: 2.1% 6.4%; RN: 4.9% 6.0%; NU: 3.8% 9.2%;  < 0.001). Median length of stay was longer for patients who underwent conversion than for those who did not (PN: 4.0 2.0 days; RN: 4.0 3.0; NU: 5.0 4.0;  < 0.0001). Thirty-day mortality rate was higher for patients who underwent conversion (PN: 0.24% 1.42%; RN: 0.73% 2.71%; NU: 1.0% 3.0%,  < 0.001). Results were confirmed in propensity score-matched cohorts. Among patients undergoing minimally invasive kidney surgery, robotics is associated with a lower rate of unplanned open conversion than laparoscopy. This relative advantage has implications on length of stay and short-term mortality rate and should be considered when weighing the costs and benefits of robotic kidney surgery.