Robot-assisted versus laparoscopic rectal resection for cancer in a single surgeon's experience: a cost analysis covering the initial 50 robotic cases with the da Vinci Si

Background Since the introduction of the da Vinci® Surgical System, several studies have been published regarding the clinical and surgical benefits of robot-assisted colorectal surgery, but few have reported a cost analysis. The aim of this study is to compare surgical parameters and the costs of robotic surgery with those of laparoscopic approach in rectal cancer based on a single surgeon’s early robotic experience. Methods Data from 25 laparoscopic (LapTME) and the first 50 robotic (RobTME) rectal resections performed at our institution by an experienced laparoscopic surgeon (> 100 procedures) between 2009 and 2014 were retrospectively analyzed and compared. Patient demographic, procedure and outcome data were gathered. Costs of the two procedures were collected, differentiated into fixed and variable costs and analyzed against the robotic learning curve according to the cumulative sum (CUSUM) method. Results Based on CUSUM analysis, RobTME group was divided into three phases (Rob1: 1–19; Rob2: 20–40; Rob3: 41–50). Overall median operative time (OT) was significantly lower in LapTME than in RobTME (270 min vs. 312.5 min, p = 0.006). A statistically significant change in OT by phase of robotic experience was detected in the RobTME group (p = 0.010). Overall mean costs associated with LapTME procedures were significantly lower than with RobTME (p < 0.001). Statistically significant reductions in variable and overall costs were found between robotic phases (p < 0.009 for both). With fixed costs excluded, the difference between laparoscopic and Rob3 was no longer statistically significant. Conclusions Our results suggest a significant optimization of robotic rectal surgery’s costs with experience. Efforts to reduce the dominant fixed cost are recommended to maintain the sustainability of the system and benefit from the technical advantages offered by the robot.