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

ABSTRACT

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.