Early ligation of the pulmonary vein can reduce the dissemination of shed tumor cells during thoracoscopic lobectomy

Objective: The sequence of vessel ligation in lobectomy can significantly affect the hematogenous spread of circulating tumor cells (CTCs). Vein-first ligation substantially reduces CTC dissemination and achieves favorable survival compared with artery-first ligation. In this study, we further explored whether the timing of pulmonary vein (PV) ligation determined according to the early and late PV ligation technique is associated with CTC dissemination.

Methods: A total of 44 patients who underwent uniform 2-port video-assisted thoracoscopic surgery lobectomy were enrolled; the subjects were divided into the early ligation group (n = 18) and late ligation group (n = 26) according to whether PV ligation was prioritized during surgery. PV blood was obtained before PV ligation and after lobe resection. CTCs were detected using telomerase reverse transcriptase-based CTC detection and validated using FlowSight and fluorescence in situ hybridization.

Results: The median postoperative PV CTC (Post-PVCTC) count was 9 (interquartile range [IQR], 6-18), which was higher than the median preoperative PV CTC (Pre-PVCTC) count of 1 (IQR, 0-3; P < .001). Clinicopathologic correlation analysis showed that the Pre-PVCTC count correlated positively with TNM stage (P = .002) and lymph node metastasis (P = .002) and that the Post-PVCTC count correlated positively with tumor density (P = .043) and vessel/lymphatic invasion (P < .030). Interestingly, although no statistical difference in the median Pre-PVCTC count was observed, the median Post-PVCTC count in the early ligation group was 16 (IQR, 9.5-36.75), whereas that in the late ligation group it was 8 (IQR, 4.75-12.25), showing a significant difference (P = .004).

Conclusions: We provide the first evidence to show that early PV ligation can prevent PVCTCs from spreading into the circulation, offering an innovative surgical concept for the principle sequence of pulmonary vessel management.