Single-port video-assisted thoracoscopic surgery subsegmentectomy: The learning curve and initial outcome

Background: We report initial surgical results and learning process of single-port video-assisted thoracoscopic surgery (VATS) subsegmentectomy in comparison with segmentectomy in our institution as the presentative of minimal invasiveness and precise resection for early stage lung cancer. Methods: All patients undergoing single-port VATS sublobar anatomic resection between January 2014 and December 2018 for clinical diagnosis of lung cancer were included. The learning curve was analyzed using the cumulative summation (CUSUM) method. Comparisons were done between those who underwent single-port VATS subsegmentectomy and segmentectomy. Results: A total of 364 patients underwent single-port VATS segmentectomy and 91 patients underwent single-port VATS subsegmentectomy were included. Lung adenocarcinoma was the most common (61.1%) diagnosis. The operative time and blood loss in the subsegmentectomy group were less than the segmentectomy group. The incidence of intraoperative complication was also lower in the subsegmentectomy group. The surgical proficiency was reached at 28 cases in single-port VATS subsegmentectomy. For primary lung cancer, the tumor size in subsegmentectomy group was smaller than segmentectomy group (1.1 cm versus 1.4 cm, p = 0.026). The resection margin was smaller in subsegmentectomy group, and both groups reached adequate margin without significant difference (94.7% versus 95.5%, p = 0.737). During the follow-up period, 2 (3.5%) patients in subsegmentectomy group and 9 (4.1%) patients in segmentectomy group developed distant metastasis. Conclusion: Single-port VATS subsegmentectomy is safe and feasible for small-sized lung lesion, providing the benefit of minimal invasiveness, preservation of pulmonary function, and clearance of lymphatic drainage at the intersegmental plane. The surgical proficiency could be achieved based on the experiences in single-port VATS segmentectomy.