Learning curve for double micro-portal video-assisted thoracoscopic lobectomy

Video-assisted thoracoscopic surgery (VATS) lobectomy serves as a standard surgical approach for the management of resectable lung cancer. The double micro-portal VATS lobectomy technique, a viable surgical procedure, has gained widespread acceptance in clinical settings within our center. In this study, we present a retrospective analysis of our institutional experience with the double micro-portal VATS lobectomy, including an assessment of the learning curve.

The cumulative sum (CUSUM) analysis method was used to analyze the learning curve of 106 cases of double micro-portal VATS lobectomy for resectable lung cancer, all belonging to the same treatment group within the Department of Thoracic Surgery, the 2nd Affiliated Hospital of Air Force Medical University of Chinese People's Liberation Army, from March 2015 to December 2016. The learning curve was derived through accumulating and fitting the operation time and intraoperative bleeding, enabling a comprehensive comparison and analysis of perioperative data across distinct learning phases.

With the gradual increase in the number of operations, the operation time gradually shortened. Through the application of CUSUM analysis, the goodness-of-fit coefficient peaked at R²=0.878, corresponding to the formula y=134.6 + 15.84×n - 0.1397×n² - 0.000215×n³. Notably, a vertex crossing occurred when the number of operations reached 51 cases. Similarly, intraoperative bleeding also exhibited a decreasing trend with the increasing number of operations. The goodness-of-fit coefficient attained its maximum value of R²=0.858 using CUSUM analysis, with the formula expressed as y=-238.89 + 81.87×x - 0.9912×x² + 0.002161×x³. A vertex crossing was achieved when the number of operations reached 49 cases. Based on these findings, 106 surgical patients were categorized into two distinct stages: the learning stage and the proficiency stage, with 51 cases serving as the dividing line. Statistically significant differences were observed in both operation time and intraoperative blood loss (IBL) between these two stages (P<0.05).

The learning curve of double micro-portal VATS lobectomy is fitted by CUSUM analysis. When the cumulative number of operation cases reaches 51 cases, the operation can achieve a relatively stable level.