Anatomic and clinical implications of venous drainage variations in superior segment resections for clinical T1N0 non-small cell lung cancer.

Background: Superior segmentectomies for clinical T1N0 non-small cell lung cancer (NSCLC) often suffer from inadequate surgical margins. Our study aimed to enhance the precision of superior segmentectomies by focusing on the anatomical features of the superior segmental vein (V) branches, and assess the relevant outcomes.

Methods: The clinical data of 646 patients with cT1N0 NSCLC who underwent video-assisted thoracic surgery (VATS) from August 2020 to August 2021 were retrospectively analyzed. A total of 521 patients were enrolled for analyzing the prevalence and drainage patterns of Vb utilizing three-dimensional reconstruction images. Then, 162 patients who underwent segmentectomy were included to analyze the outcomes of superior segmentectomy. Disease-free survival (DFS) was estimated using the Kaplan-Meier method and compared across groups with the log-rank test.

Results: The prevalence of Vb2 (a type of intersegmental vein between S and S) and Vb3 (between S and S) were 91.2% (475/521) and 66.2% (345/521), respectively, both primarily converging with other branches of V. The segmentectomy groups showed no significant differences in surgical margins, tumor size, or other malignancy-related factors, such as TNM stage. Correspondingly, during a median follow-up of 3.23 years [interquartile range (IQR), 2.99-3.61 years], the patients who underwent superior segment (S) resection achieved an overall survival (OS) rate of 100% (68/68) and a DFS rate of 97.1% (66/68), demonstrating outcomes comparable to other segmentectomies (P>0.05).

Conclusions: High prevalence of Vb2 and Vb3 was observed with minimal variation in drainage patterns. Emphasizing these veins to ensure sufficient margins and potentially reducing aggressiveness through early detection, the outcomes of superior segmentectomies in this study are comparable to other segmentectomies and superior to those reported in previous studies.