Analysis of variation in bronchovascular pattern of the right middle and lower lobes of the lung using three-dimensional CT angiography and bronchography

Objectives General thoracic surgeons must be familiar with anatomical variation in the pulmonary vessels and bronchi. Here, we analyzed the bronchovascular pattern of the right middle lobe (RML) and right lower lobe (RLL) of the lung using three-dimensional CT angiography and bronchography (3DCTAB). Methods We reviewed the anatomical patterns of the pulmonary vessels and bronchi in 270 patients using 3DCTAB images. Results The branching patterns of vessels and bronchi of RML and S 6 were classified according to the number of stems. The single-stem type was the most common, except in the artery of the RML, for which the two-stem type was the most common. The artery and bronchus of S*, which is an independent segment between S 6 and S 10 , were observed in 20.4% of cases. The branching pattern of A 7 (B 7 ) was classified into four types. The A 7 a (B 7 a) type was observed in 74.8% of cases, and was the most common. The branching pattern of the artery and bronchus of S 8−10 was classified into five and three types, respectively. The A 8 and A 9 + A 10 type, and the B 8 and B 9 + B 10 type, were observed in 68.1 and 80.4% of cases, respectively, and were the most common types. The branching pattern of V 8−10 was more complex than that of A 8−10 and B 8−10 . Conclusion We explored the bronchovascular patterns of RML and RLL and their frequencies using a large number of 3DCTAB images. Our data can be used by thoracic surgeons to perform safe and precise lung resections.