Figure 2.

Illustration of the surgical procedure with the assistance of 3D image navigation. The sequence of the surgical procedure was from (A-D,F). The dissection begun at the central vein, and all following dissections were kept going along it. (E) 3D image from the right superior view revealed the anatomic structures of the right upper lobe. The targeted subsegments were S²b and S³a, the targeted arteries were A²bi, A²bii, A³ai and A³aii, the targeted bronchi were B²b and B³a, and the targeted veins were inferior V²c and superior V²c. The veins marked with blue triangles were the intersubsegmental veins, which were the marks of intersubsegmental demarcation and should be preserved. All solid lines reflected the one-to-one correspondence between the actual and virtual anatomic structures.