The B1 defective type of bifurcated right upper lobe bronchus

Anatomy of the lung revisited by 3D-CT imaging

The anatomy of the lung was originally described based on data acquired from cadaveric studies and surgical findings. Over time, computed tomography (CT) and three-dimensional (3D) imaging techniques have been developed, allowing for reconstruction and understanding of lung anatomy in a more intuitive way. The wide adoption of 3D-CT imaging technology has led to a variety of anatomical studies performed not only by anatomists but also by surgeons and radiologists. Such studies have led to new or modified classification systems, shed light on lung anatomy from a useful surgical viewpoint, and enabled us to analyze lung anatomy with a focus on particular anatomical features. 3D images also allow for enhanced pre- and intra-operative simulation, improved surgical safety, enhanced educational utility, and the capacity to perform large-scale anatomical studies in shorter time frames. We will review here the key features of 3D-CT imaging of the lung, along with representative anatomical studies regarding (I) general lung anatomy, (II) anatomy of the right and left lobes, and (III) features of interlobar vessels. The current surge of 3D imaging analysis shows that the field is growing, with the technology continuing to improve. Future studies using these new and innovative methodologies will continue to refine our understanding of lung anatomy while enhancing our ability to perform safe and effective surgical resections.

The detailed classification of the interlobar artery and the artery crossing intersegmental planes in the right upper lobe

Background

With the prevalence of three-dimensional computed tomography bronchography and angiography (3D-CTBA) and the development of anatomical segmentectomy, several studies have analyzed the branching patterns of peripheral segmental arteries in the right upper lobe (RUL). Nevertheless, the detailed classification of the branching patterns of the interlobar artery and the artery crossing intersegmental planes remains unknown. Thus, we conducted a retrospective study to analyze the variations of the interlobar artery and the artery crossing intersegmental planes in the RUL using 3D-CTBA.

Materials and methods

A total of 600 patients with ground-glass opacity (GGO) who had undergone 3D-CTBA preoperatively at Hebei General Hospital between September 2020 and September 2022 were used for the retrospective study. We reviewed the anatomical variations of the RUL arteries in these patients using 3D-CTBA images.

Results

The branching patterns of the RUL artery were classified into the following four categories: trunk superior (Tr. sup), Tr. sup + interlobar artery, Tr. sup + trunk inferior (Tr. inf), and Tr. sup + Tr. inf + interlobar artery. The branching patterns of the interlobar artery were subclassified into four subtypes: posterior ascending artery (A. pos), anterior ascending artery (A. ant), A. pos + A. ant, and ascending artery (A. asc). The artery crossing intersegmental planes contains two types: type A, anterior subsegmental artery crossing intersegmental planes (AX¹b); type B, recurrent artery crossing intersegmental planes (AX. rec).

Conclusion

The variation types of blood vessels in the RUL are complex. This study explored the detailed classification of the interlobar artery and the artery crossing intersegmental planes. It can help thoracic surgeons understand the anatomy variations, accurately locate lesions before surgery, and effectively plan surgeries.

What is the correlation between the defective and splitting posterior segmental bronchus and recurrent artery crossing intersegmental planes in the right upper lobe?

Background

With the prevalence of three-dimensional computed tomography bronchography and angiography (3D-CTBA) and the development of anatomical segmentectomy, studies have confirmed the increased incidence of anomalous veins in patients with tracheobronchial abnormalities. Nevertheless, the characteristic anatomical correlation between bronchus and artery variation remains unknown. Thus, we conducted a retrospective study to investigate recurrent artery crossing intersegmental planes and their associated pulmonary anatomical features by analyzing the incidence and types of the right upper lobe (RUL) bronchus and the artery composition of the posterior segment.

Materials and Methods

A total of 600 patients with ground-glass opacity who had undergone 3D-CTBA preoperatively at Hebei General Hospital between September 2020 and September 2022 were included. We reviewed the anatomical variations of the RUL bronchus and artery in these patients using 3D-CTBA images.

Results

Among all 600 cases, the defective and splitting B2 contained four types of the RUL bronchial structure: B1 + BX2a, B2b, B3 (11/600, 1.8%); B1, B2a, BX2b + B3 (3/600, 0.5%); B1 + BX2a, B3 + BX2b (18/600, 3%); B1, B2a, B2b, B3 type (29/600, 4.8%). The incidence of recurrent artery crossing intersegmental planes was 12.7% (70/600). The incidence of recurrent artery crossing intersegmental planes with and without the defective and splitting B2 was 26.2% (16/61) and 10.0% (54/539), respectively (p < 0.005).

Conclusions

In patients with defective and splitting B2, the incidence of recurrent artery crossing intersegmental planes was increased. Our study provides certain references that surgeons can use to plan and perform RUL segmentectomy.

Elucidating the anatomy of the quadrivial pattern of the right upper lobe bronchus using 3D-CT images

Background

A preoperative understanding of the thoracic anatomy of the patients with the quadrivial pattern of branching of the right upper lobe is key to successful surgery. We analyzed the quadrivial pattern of division of the right upper lobe bronchus of patients using three-dimensional (3D) computed tomography (CT) angiography and bronchography.

Methods

A total of 212 consecutive adult patients who had undergone thoracic CT scans before surgery at the Zhujiang Hospital of the Southern Medical University from August 2020 to August 2021 was used for retrospective study. The 3D-CT images were taken using Mimics software. Radiology technicians processed all the 3D images, and thoracic surgeons confirmed the validity of all the reconstructions.

Results

Six (2.83%) were identified as having a quadrivial pattern of division of the right upper lobe bronchus with 1 female, and 5 males. Based on the number of pulmonary artery branches, 5 (83.3%) and 1 (16.7%) were classified as “trunk superior (Tr.sup) + ascending artery (A.asc) and Tr.sup + trunk inferior (Tr.inf) + ascending artery (A.asc) (1/6, 16.7%). Based on the number of ascending artery branches, the patients were also divided into type A (3/6, 50%) and type B (3/6, 50%). The patients were also divided into 1 of the following three types based on the origins of the A2: (I) A2 originates from A6 (1/6, 16.7%); (II) A2 originates from the pulmonary trunk (4/6, 66.7%); and (III) A2a originates from A3, and A2b originates from the pulmonary artery stem (1/6, 16.7%). According to the number of A1b branches, patients were divided into two types: (I) 1 branch (4/6, 66.7 %); and (II) 2 branches (2/6, 33.3 %). In the present study, anterior + central type was observed which classified into two types: (I) type Iab, the anterior vein ran from V1a to V1b (4/6, 66.7%); and (II) type Ib, the anterior vein ran from V1b only (2/6, 33.3%).

Conclusions

3D-CT was successfully used for analyzing the quadrivial bronchovascular patterns of the right upper lobe bronchus. Our study provides certain references to perform anatomical pulmonary segmentectomy, which should improve the success rate of operations.

Analysis of bronchial and vascular patterns in left upper lobes to explore the genesis of mediastinal lingular artery and its influence on pulmonary anatomical variation

BACKGROUND

For thoracic surgeons, three-dimensional computed tomography bronchography and angiography (3-DCTBA) is a convenient way to analyze pulmonary variations before segmentectomy. Mediastinal lingular artery (MLA) is one of the representative variations.

METHODS

The 3-DCTBA data of left upper lobe (LUL) were collected from patients who underwent pulmonary surgery from January 2018 to December 2019. We reviewed the patterns of bronchi and pulmonary vessels and grouped them according to different classifications.

RESULTS

Among all the 404 cases of 3-DCTBA, mediastinal lingular artery (MLA) was found in 107 cases (26.49%). The patterns of B³ and the vein in left upper division (LUD) are distinct between mediastinal (M-type) group and interlobar (IL-type) group. The patterns of bronchi and veins in lingular division, as well as the pattern of pulmonary artery in LUD, have no differences between M-type and IL-type groups.

CONCLUSIONS

Mediastinal lingular artery is speculated to originate from the variation of B³, and the MLA independently influences the venous pattern in LUD in turn.

Analysis of the variation pattern in left upper division veins and establishment of simplified vein models for anatomical segmentectomy

Background

Three-dimensional computed tomography bronchography and angiography (3D-CTBA) is a powerful tool to analyze pulmonary anatomy. We used 3D-CTBA to analyze variations of the pulmonary veins of the left upper division (LUD) and created a simplified LUD vein model.

Methods

Between January 2019 and October 2019, 124 patients with left-sided pulmonary lesions were admitted and underwent 3D-CTBA prior to surgery. We reviewed the anatomical variations of the LUD veins in these patients using 3D-CTBA images and classified them according to their position in relation to the bronchus. To facilitate this process, the same nomenclature as that used to describe the veins of the right upper lobe (RUL) is used for the LUD.

Results

The pattern of LUD veins could be classified into three forms: an anterior + central form, an anterior form and a central form. For the central form, V ¹⁺² a, V ¹⁺² b, V ¹⁺² c and V ¹⁺² d drained into V. cent. For the anterior form, V ¹⁺² d drained into V. ant. The anterior + central form could be further classified into three subtypes (V abc, V ab and V a).

Conclusions

This is the first report to categorize the pattern of veins in the LUD. This may facilitate the creation of simplified models for use in pre-operative planning for segmentectomy.