Thoracoscopic segmentectomy and lobectomy assisted by three-dimensional computed-tomography bronchography and angiography for the treatment of primary lung cancer

Figure 1 Preoperative flow diagram of three-dimensional reconstruction technique using Mimics software. The pulmonary bronchus, artery and vein were distinguished from one another and marked out with different colors: white, bronchus; red, pulmonary artery; purple, pulmonary vein. 3D: 3-dimensional; CT: Computed-tomography.

Figure 2 Presurgical confirmation of anatomical variations. Preoperative three-dimensional (3D) computed-tomography bronchography and angiography images can clearly and vividly display the targeted segmental structure and variations of vessels and bronchi. A: The bronchus of the right upper lobe is divided into the apical segmental bronchus (B¹), posterior segmental bronchus (B²), and anterior segmental bronchus (B³). The distance between the B³a and B³b of the anterior segmental bronchus is very great; B: The 3D image reveals the variations of the right upper-lobe artery: the A³a originates from the distal end of the A¹, while the enlarged A³b coexists with the proximal end of the A¹. Care should be taken to protect A¹ when dealing with the A³b during the surgery; C: The segmental and sub-segmental veins of the right upper lobe are labeled successively in the 3D image. There was no central vein, and the V² a flowed into the apex vein (V¹) through the upper pulmonary hilum; D: The 3D image reveals the variations of the B² and V² in the right upper lobe. The B² branched out separately, but the B¹ and B³ arose from a common stem. When the B¹ is resected, the surgeon often accidentally resects the B³ as well. Additionally, the right upper posterior pulmonary vein (V²) merged into the right inferior pulmonary vein (RIPV). When the surgeon deals with the right lower pulmonary vein, the V² could be mistakenly cut off altogether, leading to postoperative hemoptysis; E: The 3D image demonstrates the variation of the mediastinal lingual-segment artery (Med A⁴⁺⁵) in the left upper lobe. The A⁴b and A⁵ of the left upper lingual-segment artery originated from the upper pulmonary trunk, while the A⁴a originated from the interlobar-fissure artery separately. When left superior segmentectomy is performed, it is possible to cut off the A⁴b and A5 at the same time, resulting in decreased pulmonary blood flow to lingular-segment lung tissue and an imbalanced ventilation: Blood flow ratio.

Figure 3 Identification of sufficient surgical margin and preoperative surgery simulation. A: Chest computed tomography (CT) scan showed pure ground-glass opacity in the right upper lobe; B: We simulated surgery preoperatively, guided by a three-dimensional computed-tomography bronchography and angiography (3D-CTBA) images. The image showed that the targeted segmental structures needing to be successively resected were the V³c, A³b, B³b, and V³b; C: We precisely identified sufficient surgical margin after calculating the distance from the lesion to the predetermined cutting margin on the 3D-CTBA image. The safety margin was defined as a sphere extending at least 2 cm outside the lesion or 2 cm greater than the tumor size; D: The yellow area denotes the extent of targeted lung parenchyma RS³b. Afterward, we meticulously performed segmentectomy of the RS³b, as illustrated in Figure 4.

Figure 4 Illustration of the precise surgical procedure navigated by three-dimensional computed-tomography bronchography and angiography. With the assistance of three-dimensional computed-tomography bronchography and angiography (3D-CTBA), we meticulously performed thoracoscopic segmentectomy of the RS³b. A series of techniques were involved in this procedure, including location of the pulmonary nodules, resection of targeted vessels and bronchi, preservation of intersegmental veins, and identification of the intersegmental demarcation. A–D: Images showing the resection sequence for the targeted vessels and bronchi, including the V³c, A³b, B³b, and V³b, respectively. The intersegmental demarcation (yellow dotted line) was defined by the improved inflation–deflation method, assisted by 3D-CTBA. The intersegmental veins V¹b and V³a were carefully preserved. The surgeons precisely identified, separated, and dissected the targeted segment based on the cone-shaped principle; E, F: View of the hilum after RS³b removal reveals stumps of targeted vessels and bronchi, which was completely consistent with the preoperative 3D-CTBA images.