Is prior laparoscopy experience required for adaptation to robotic rectal surgery? Feasibility of one-step transition from open to robotic surgery

Purpose: The objective of this study is to ascertain the impact of laparoscopic colorectal surgery (LCS) experience on the learning curve of robotic rectal cancer surgery (RRS). Whether LCS experience is mandatory on overcoming the learning curve of RRS or not remains undetermined. Methods: Before starting the robotic procedure, surgeon A had a limited experience of less than 30 LCS cases, whereas surgeon B had performed more than 300 cases of LCS. From the beginning, 100 consecutive, unselected RRS cases performed by each of the two surgeons were retrospectively analyzed (groups A and B). Perioperative surgical and oncologic outcomes were compared between the two groups. Results: Clinicopathological characteristics between the two groups were similar. One case in group A was converted to open surgery. Mean operation time was shorter in group A than that of group B (272 vs. 344 min, p<0.001). Overall perioperative morbidity rates were not different between the two groups (17.0 vs. 10.0%, p =0.214). There was no difference of circumferential resection margin positivity rate and retrieved lymph node numbers. In group A, the operation time decreased with a steep slope until 17 cases on the moving average curve. The slope in group B maintained a steady state and showed no remarkable changes throughout the study period. Conclusions: A one-step transition from open to robotic rectal cancer surgery can be achieved without having extensive prior laparoscopic experience.