VARIATIONS IN THE BRONCHOVASCULAR PATTERNS OF THE RIGHT LOWER LOBE OF FIFTY LUNGS

Prevalence and anatomical characteristics of subsuperior segment in lung lower lobe

OBJECTIVE

The subsuperior segment is an atypical pulmonary segment of the lung lower lobe. With the increased application of segmentectomy, it has received increased attention from thoracic surgeons. Studies of the subsuperior segment are scarce and mostly on the basis of small-sample autopsy studies, whose described characteristics are inconsistent with intraoperative observations. Our objective was to accurately define the subsuperior segment and elucidate its prevalence and anatomical characteristics in detail.

METHODS

A total of 2194 chest computed tomography images were obtained using separate random sampling on the basis of the amount of data available to each of the 6 thoracic surgery institutions in different provinces covering various regions of China. All of the images were reconstructed in 3 dimensions. Subsuperior segments were screened according to their new definition and statistically analyzed for their prevalence and anatomical characteristics.

RESULTS

The prevalence of subsuperior segments was 32.04%, with 413 on the right (18.79%); the value was higher than that on the left (347; 15.81%). The average volume of the subsuperior segment was 52.81 ± 21.96 cm3. Only 1 bronchus was detected in the unilateral subsuperior segment, with an average diameter of 2.53 ± 0.61 mm. Only 1 pulmonary artery was observed in most of the subsuperior segments (89.34%), but 81 cases (10.66%) had 2 in our study. One intersegmental vein of the subsuperior segment was the most common situation on both sides.

CONCLUSIONS

Using a multicenter large-sample study, we calculated a 32.04% prevalence and systematically detailed the anatomical characteristics of the subsuperior segment in the lung lower lobe, corrected previous reports, and supplemented pulmonary anatomical studies.

Application of three-dimensional reconstruction of left upper lung lobes in anatomical segmental resection

BACKGROUND

The lobar and segmental anatomy are the basis for anatomical pulmonary segmentectomy.

METHODS

From October 2017 to June 2021, 136 patients with small pulmonary nodules scheduled for anatomical pulmonary segmentectomy at our institution underwent three-dimensional (3D) lung reconstruction. The anatomy of the left upper lobe (LUL) was statistically analyzed and graphically mapped using the reconstructed models, and the role of this reconstruction method in performing pulmonary segmentectomy was explored.

RESULTS

Through the analysis of the reconstructed models, the upper stem (S1 + 2 + 3) bronchus was classified as having two (94/136 cases) or three branches (42/136 cases). The upper stem artery had two branches in 24/136 patients, three in 60/136 cases, four in 44/136 cases, and five in 8/136 cases. A total of 103/136 upper stem veins had two branches, 26/136 had three branches, and 7/136 had four branches. The lingual stem (S4 + 5) bronchus was two-branched in 116/136 cases and three-branched in 20/136 cases, while the lingual artery was single-branched in 61/136 cases, two-branched in 70/136 cases, and three-branched in rare cases (5/136 cases). The lingual stem vein was unbranched in 119/136 cases and two-branched in 17/136 cases. Additionally, six unusual variants (<5%) were identified: one in the bronchus, with four cases; three in the pulmonary artery, with six cases; and two in the pulmonary vein, with two cases.

CONCLUSIONS

3D reconstruction can yield results similar to specimens for lung segment studies. The reconstruction strategy and the data presented in this article will be valuable references for thoracic surgeons performing anatomic resections.

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 S⁶ 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 S⁶ and S¹⁰, were observed in 20.4% of cases. The branching pattern of A⁷ (B⁷) was classified into four types. The A⁷a (B⁷a) type was observed in 74.8% of cases, and was the most common. The branching pattern of the artery and bronchus of S⁸⁻¹⁰ was classified into five and three types, respectively. The A⁸ and A⁹ + A¹⁰ type, and the B⁸ and B⁹ + B¹⁰ type, were observed in 68.1 and 80.4% of cases, respectively, and were the most common types. The branching pattern of V⁸⁻¹⁰ was more complex than that of A⁸⁻¹⁰ and B⁸⁻¹⁰.

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.

Electronic supplementary material

The online version of this article (doi:10.1007/s11748-017-0754-4) contains supplementary material, which is available to authorized users.