The branching patterns of bronchi and pulmonary arteries are associated with lingula division volume

Three-dimensional (3D) computed tomography (CT) bronchography and angiography is a powerful tool for analyzing pulmonary anatomy. We conducted a large-sample, single-center study using 3D CT to systematically and comprehensively describe the bronchial and vascular anatomical features of the lingula.

After applying the study exclusion and inclusion criteria, a total of 4,862 participants who underwent thin-slice CT scans from January 2019 to June 2024 at the Department of Thoracic Surgery, Yichang Central People's Hospital were enrolled in this retrospective study. Data such as the clinical characteristics of blood vessels and bronchi were reviewed in this study.

The B4-B5 type was the most common anatomical pattern (4,692 cases, 96.5%, P<0.001). The B4-B5 type can be classified based on its position as follows: vertical (Type I) and horizontal (Type II). The incidence of Type I (91.13%) was significantly higher than that of Type II (8.87%) (P<0.001). The B4 diameter was significantly larger in Type I than Type II (4.39±0.81 vs. 3.31±0.37 mm, P<0.001), but there was no significant difference in either B4+5 or B5 diameter between the two types. The lingula volume was significantly larger in Type I than Type II (330.48±84.17 vs. 280.76±56.22 mL, P=0.01). Compared to Type II, Type I had a significantly larger lingula volume/total lung volume (8.25%±0.93% vs. 7.30%±1.41%, P<0.001), lingula volume/left lung volume (17.82%±2.19% vs. 14.23%±2.05%, P<0.001), and lingula volume/left upper lung volume (34.93%±2.07% vs. 27.59%±2.22%, P<0.001). Compared with the interlobar type group, the mediastinal type group had a significantly larger lingula volume/total lung volume (8.96%±1.33% vs. 7.93%±1.07%, P<0.001), lingula volume/left lung volume (19.73%±1.57% vs. 16.96%±2.39%, P<0.001), and lingula volume/left upper lung volume (37.33%±2.65% vs. 31.86%±3.87%, P<0.001).

This study systematic classification of lingular bronchial and arterial branching patterns into eight subtypes, and explored the relationship between these subtypes and lung segment volume. This was also the first study to report a positive correlation between pulmonary artery branching patterns, bronchi branching patterns, and lung volume. Our findings may facilitate the creation of simplified models for use in preoperative planning for segmentectomy.