Anatomical characteristics of superior and pulmonary subsuperior segment in right lower lobe based on...

Segmentectomy has been widely performed in clinical practice, which required a comprehensive understanding of anatomical structure. In right lower lobe, studies of superior segment (S⁶) were relatively small-sized. And only one study focusing on subsuperior segment (S∗) was published, which showed different results with previous ones. As the close relationship between S⁶ and S∗, variation types and their prevalence rate were reported, aiming to providing larger-size study of S⁶ and showing new evidence on anatomical structure of S∗.

800 CT imaging data were collected from patients in our hospital. Three-dimensional reconstruction was performed after quality check. All images were screened according to the definition of corresponding segment and anatomical variations were analyzed.

The proportion of S⁶ variation types in the largest scale (718 patients) was reported with no significant difference compared to previous studies and newly classified subtypes of two-stem V⁶. The prevalence rate for S∗ in right lower lobe reached 28.3 % (203/718) with similar proportion of three types. Variation types and origins of pulmonary artery were analyzed in detail, finding two-stem A∗ only be observed in type III B∗.

Through this study, the variation types and incidence rate of S⁶ were confirmed, and a different result of S∗ has been provided as well. The feasibility of the current classification standards and proposed new subclassifications were verified. The results would be a supplement to lung segmental anatomy and could advance researches in the future.