Anatomic segmentectomy for early lung cancer is one of the biggest hotspots in thoracic surgery in recent years. It can not only completely resect the tumor, but also preserve the normal lung tissue to the maximum extent. The distribution of bronchus, artery and vein in pulmonary segment exists variations in some patients. The key to the implementation of this operation is to accurately grasp the anatomical structure of the target segment. The 3D-CTBA can provide a precise anatomical structure, identify the intrasegmental and intersegmental veins from different views. Some complicated pulmonary segmentectomy should be performed under the guidance of 3D-CTBA[9, 10].
The efficacy of 3D reconstruction for thoracic surgery has been previously described, Kimihiroet al.  first reported the application of 3D-CTBA in VATS segmentectomy. At present, the main softwares for 3D reconstruction of segment include IQQA, DeepInsight, etc[13, 14]. All the reconstructive softwares can offer precise anatomical structure of pulmonary segments, but sometimes, it is difficult for surgeons to skillfully use them. In our institution, with the assistance of the radiologists, we adopt the computed tomography pulmonary angiography (CTPA)-based technology to reconstruct the anatomic structure for each patient who undergoing segmentectomy. It shows the precise structure of bronchi, arteries and veins in a natural surgical field view, and the results are also satisfactory.
RS2 segmentectomy is a common procedure in all kinds of segmental resection, but the anatomic variations may increase the difficulty and risk. Xinfeng et al. reported a tracheal bronchus and a variable central vein entering the left atrium dorsal to the right pulmonary artery trunk in a patient underwent VATS RS2 segmentectomy. Tadashi et al.  reported a patient with anatomic variations in bronchi and pulmonary vessels during thoracoscopic RS2 segmentectomy. However, to the best of our knowledge, bronchial variation associated with variant pulmonary vessels has rarely been reported. The normal anatomic structure of RS2 consists of B2, Asc.A2, the recurrent artery (Rec.A2), intrasegmental veins (V2tand V2b) and intersegmental veins (V2aand V2c), but in this case, the 3D-CTBA revealed multiple variations: (1) The bronchopulmonary trees of the right upper lobe were divided into (B2 + B1a)and (B3 + B1b ), the (B2 + B1a) variation might have been mistaken for B2 without the guidance of3D-CTBA; (2)There was only one intrasegmental vein (V2t) without another rintrasegmental vein (V2b), intersegmental veins might have been transected as intrasegmental veins without the preoperative 3D-CTBA; (3) The posterior segmental arteries originated from the superior trunk without Asc.A2, they were very difficult to expose, so we released the hilum of segment first to expose the arteries sufficiently, then the artery was ligated safely, this novel strategy has rarely been reported. In conclusion, we present a successful strategy for VATS RS2 segmentectomy with multiple anatomic variations.