Preoperative evaluation of the segmental artery of left upper lobe by thin-section CT and 3d-CTA

Understanding pulmonary artery (PA) branches and their variations is crucial for successful lung resection. We aimed to evaluate the segmental PA branching pattern of the left upper lobe (LUL) using thin-section computed tomography (TSCT) images and 3D-CT angiography (3D-CTA).

This study included 108 patients who underwent CTA and left upper lobectomy. The segmental PA branching pattern of the LUL was meticulously identified by two thoracic radiologists using 3D-CTA and TSCT images. The lingular artery branches from the left PA (LPA) were classified into mediastinal type (pars mediastinalis: PM), interlobar type (pars interlobaris: PI), and PI originating from the lower portion (PI'), specifically from A8. The intraoperative findings of the PA branches of the LUL were compared with the preoperatively obtained 3D-CTA and TSCT images in each patient's case.

The median (range) number of LPA branches of the LUL was 4.36 (3-8). The most common number of A1 + 2 branches was two, seen in 34 cases (31.5%). One or more branches of A1 + 2c directly originating from the LPA were found in 63 cases (58.3%). The number of branches of A3 was single in 85 cases and the most frequent (78.7%). Instances where one or more branches of A3a directly originated from the LPA were found in seven cases (6.5%). A1 + 2 and A3 origins were separate and independent in 40 cases (37.0%). As the branching pattern of the lingular artery, PI/PI' was most frequent (61.1%). PI´ was observed in 26 cases (24.1%). Inter-observer agreement for A1 + 2, A1 + 2c, A3, A3a, and lingular artery branching patterns was moderate to substantial (κ = 0.53-0.72). Preoperative 3D-CTA and TSCT images identified 99.8% of LPA branches compared to intraoperative findings, except one.

The segmental PA branching pattern of the LUL can be evaluated using TSCT and 3D-CTA images, providing precise preoperative information.