Fig. 2

a Intraoperative image showing V^1–3 on the ventral side of the mediastinum. b Intraoperative image showing the branches of A3, A^1 + 2_a, A^1 + 2_b + c, and A^4 + 5. c Intraoperative image showing V^1 + 2_b joining the IPV. (D) Intraoperative image showing B^1 + 2 + B³ on the dorsal side of the left main pulmonary artery. e Intraoperative image after left upper division segmentectomy. IPV, inferior pulmonary vein