Initial Learning Curve and Stereotypical Use of Extra Arm During da Vinci Chest Procedures of McKeown Esophagectomy

Objective: McKeown esophagectomy facilitates extensive lymphadenectomy for the optimal management of esophageal cancer. Robot-assisted esophagectomy (RAE) was introduced in an attempt to reduce the incidence of postoperative complications. The da Vinci System has 3 active robotic arms in addition to the camera scope, and an extra robotic arm (ERA) is generally used to maintain a fine and stable operative field. However, the optimal use of an ERA has not been documented. In addition, the learning curve of the RAE using the da Vinci System remains controversial. In this study, we aimed to determine the optimal use of an ERA in association with the initial learning curve of robotic McKeown esophagectomy with extremely extensive lymphadenectomy. Methods: We reviewed 81 consecutive patients who underwent RAE. To determine whether stereotypical use of an ERA after establishment of its optimal use accounted for the learning curve, we measured the duration of 14 steps and the duration when performed with optimal use of an ERA in the corresponding step by reviewing video-recorded procedures. We then calculated the ratio as the degree of stereotypical use of the ERA during the da Vinci chest procedures. Results: The cumulative sum method showed that the learning curve required 27 cases of RAE. In addition, stereotypical use of the ERA was significantly associated with the learning curve of RAE. Conclusions: Establishment of optimal use of an ERA could help to accelerate the learning curve in da Vinci chest procedures during McKeown esophagectomy with extensive lymphadenectomy.