Background Robotic surgery for gastric cancer patients has been increasing because of its many advantages over conventional laparoscopic surgery. Despite the suggestion that robotic surgery may lessen the learning curve for complex laparoscopic procedures, little is known about the learning curve for robotic gastrectomy. This study aimed to assess the learning curve of robotic gastrectomy for patients with cancer by analyzing the operation time. Methods The first 20 consecutive cases of robot-assisted distal gastrectomy with lymphadenectomy for gastric cancer performed by three experienced laparoscopic surgeons' using the da Vinci system were collected and reviewed. A nonlinear least-squares method was developed and used to analyze the learning curves. Results Overall, the mean operation time was 247.3 ± 45.7 min, depending on each surgeon's laparoscopic experience and the patient's characteristics. After control was used for confounding factors, the stabilized operation time decreased to 211.8 min. The operation time stabilized at 8.2 cases and was reduced 111.4 min from the first case. A stable operation time was reached in 9.6 cases by surgeon A, in 18.1 cases by surgeon B, and in 6 cases by surgeon C. The stable operation time was 149.2 min for surgeon A, 127.1 min for surgeon B, and 236.8 min for surgeon C, and the reduction in operation time from the first case to stabilization was 233 min for surgeon A, 76.7 min for surgeon B, and 154.6 min for surgeon C. Conclusions Surgeons with sufficient experience in laparoscopic gastrectomy can rapidly overcome the learning curve for robotic gastrectomy. In addition, the surgeon's experience with laparoscopic gastrectomy affects the operation time after stabilization and the reduction in operation time.
All Science Journal Classification (ASJC) codes