Three-dimensional imaging anatomical research and clinical implications of V^{1   +2} d in the left upper lung

To investigate the distribution pattern of V¹⁺² d in the left superior pulmonary vein and its clinical significance.

A retrospective analysis was conducted using three-dimensional computed tomographic bronchography and angiography (3D-CTBA) data from 500 lung cancer patients. Statistical analyses were performed to evaluate the incidence and drainage patterns of the three sub-branches of V¹⁺² d, namely V¹⁺² d1, V¹⁺² d2 and V¹⁺² d3. Furthermore, clinical data from 10 patients' lesions involving V¹⁺² d were reviewed to illustrate the impact of adjacency to V¹⁺² d on the surgical approach.

The incidences of V¹⁺² d1, V¹⁺² d2 and V¹⁺² d3 were 100%, 76.4% and 100% respectively. The relative interlobar distribution sizes of B³ a and B¹⁺² c and the left upper division (LUD) vein type influenced the incidence of V¹⁺² d2 (p < 0.05; p < 0.001). V¹⁺² d2 predominantly occurred in B³ a = B¹⁺² c and B¹⁺² c > B³ a patterns. V¹⁺² d2 was entirely absent in the B³ a > B¹⁺² c pattern. V¹⁺² d2 exhibited a higher incidence in both the central vein (CV) type and the noncentral vein (NCV) type when compared to the semi-central vein (SCV) type (100% vs. 100% vs. 64.8%). The most prevalent venous drainage pattern was the three sub-branches of V¹⁺² d constituting a major trunk to drain (41.2%). All 10 cases with lesions involving V¹⁺² d successfully underwent sublobar resection with no complications, and the surgical margin was ≥2 cm.

The three sub-branches of V¹⁺² d exhibit a high incidence with diverse distribution patterns, yet a discernible pattern exists. For inter- or multi-intersegmental nodules involving V¹⁺² d, combined segmentectomy and subsegmentectomy or combined subsegmentectomy can ensure the safe margin.