The learning curve of a bronchus-first method in bi-port video-assisted thoracoscopic surgery for left upper lobe lung cancer

Abstract

Video-assisted thoracic surgery (VATS) has been widely used in lung cancer treatment. However, VATS left upper lobectomy (LUL) is complex due to the intricate branching pattern of the left pulmonary artery (PA). Nevertheless, VATS right upper lobectomy can be simplified through a bronchus-first and simultaneous vessel stapling technique. In this study, the learning curve was obtained while ensuring favorable oncological outcomes using bronchus-first method for VATS LUL. First, retrospective data of 148 consecutive patients who underwent VATS LUL (bronchus-first method) for non-small cell lung cancer (NSCLC) from March 2018 to October 2020 were analyzed. The learning curve was then assessed via cumulative sum (CUSUM) analysis. Moreover, data at different stages of the learning curve, including operation time, blood loss, postoperative hospital stay, lymph node harvested, thoracotomy conversion, postoperative complications, endoscopic stapler consumptions, and 3 year overall survival, were recorded. The learning curve was best modeled as the equation: y = - 7.78 + 2.05x-2.23 × 10^-2x² + 6.43 × 10^-5x³, with a good-to-fit test R² = 0.97. The surgeon entered the proficient stage (59th case-148th case) after consecutive operations of 58 cases (learning stage, 1st case-58th case). Notably, more lymph nodes were harvested in the proficient stage than in the learning stage (17.69 ± 1.47 vs. 15.53 ± 1.43, P < 0.01). Compared with the learning stage, the proficient stage was associated with shorter operation time (114.28 ± 8.56 min vs. 126.81 ± 7.30 min, P < 0.01), fewer blood loss (44.22 ± 7.75 mL vs. 57.41 ± 22.98 mL, P < 0.01), shorter postoperative hospital stay (6.02 ± 0.99 d vs. 7.22 ± 1.34 d, P < 0.01), and fewer endoscopic stapler consumptions (5.89 ± 0.64 vs. 6.53 ± 0.50, P < 0.01). However, thoracotomy conversion (4/90 vs. 5/58, P = 0.32), postoperative complications (10/90 vs. 11/58, P = 0.23) and 3 year overall survival (62.2% vs. 50.8%, log-rank test, P = 0.11) showed no significant difference between the two stages. The surgeon with former single-direction VATS lobectomy experience can master bronchus-first VATS LUL after attending to 58 cases.

Keywords: Bi-port video-assisted thoracoscopic surgery; Bronchus-first method; Learning curve; Left upper lobectomy; Lung cancer.