Zeng Wen, Wang Jiarong, Weng Chengxin, Peng Wanlin, Wang Tiehao, Yuan Ding, Huang Bin, Zhao Jichun, Xia Chunchao, Li Zhenlin, Guo Yingkun
Department of Radiology, West China Hospital, Sichuan University, Chengdu, China.
Division of Vascular Surgery, Department of General Surgery, West China Hospital, Sichuan University, Chengdu, China.
Quant Imaging Med Surg. 2024 Apr 3;14(4):2800-2815. doi: 10.21037/qims-23-1321. Epub 2024 Mar 28.
Thoracoabdominal aortic aneurysms (TAAAs) are rare but complicated aortic pathologies that can result in high morbidity and mortality. The whole-aorta hemodynamic characteristics of TAAA survivors remains unknown. This study sought to obtain a comprehensive view of flow hemodynamics of the whole aorta in patients with TAAA using four-dimensional flow (4D flow) magnetic resonance imaging (MRI).
This study included patients who had experienced TAAA or abdominal aortic aneurysm (AAA) and age- and sex-matched volunteers who had attended China Hospital from December 2021 to December 2022 in West. Patients with unstable ruptured aneurysm or other cardiovascular diseases were excluded. 4D-flow MRI that covered the whole aorta was acquired. Both planar parameters [(regurgitation fraction (RF), peak systolic velocity (V), overall wall shear stress (WSS)] and segmental parameters [pulse wave velocity (PWV) and viscous energy loss (VEL)] were generated during postprocessing. The Student's -test or Mann-Whitney test was used to compare flow dynamics among the three groups.
A total of 11 patients with TAAA (mean age 53.2±11.9 years; 10 males), 19 patients with AAA (mean age 58.0±11.7 years; 16 males), and 21 controls (mean age 55.4±15.0 years; 19 males) were analyzed. The patients with TAAA demonstrated a significantly higher RF and lower Vmax in the aortic arch compared to healthy controls. The whole length of the aorta in patients with TAAA was characterized by lower WSS, predominantly in the planes of pulmonary artery bifurcation and the middle infrarenal planes (all P values <0.001). As for segmental hemodynamics, compared to controls, patients with TAAA had a significantly higher PWV in the thoracic aorta (TAAA: median 11.41 m/s, IQR 9.56-14.32 m/s; control: median 7.21 m/s, IQR 5.57-7.79 m/s; P<0.001) as did those with AAA (AAA: median 8.75 m/s, IQR 7.35-10.75 m/s; control: median 7.21 m/s, IQR 5.57-7.79 m/s; P=0.024). Moreover, a greater VEL was observed in the whole aorta and abdominal aorta in patients with TAAA.
Patients with TAAA exhibited a stiffer aortic wall with a lower WSS and a greater VEL for the whole aorta, which was accompanied by a higher RF and lower peak velocity in the dilated portion of the aorta.
胸腹主动脉瘤（TAAA）是一种罕见但复杂的主动脉病变，可导致高发病率和死亡率。TAAA幸存者的全主动脉血流动力学特征尚不清楚。本研究旨在利用四维血流（4D流）磁共振成像（MRI）全面了解TAAA患者全主动脉的血流动力学情况。
本研究纳入了2021年12月至2022年12月在西部中国医院就诊的TAAA或腹主动脉瘤（AAA）患者以及年龄和性别匹配的志愿者。排除不稳定破裂动脉瘤或其他心血管疾病患者。采集覆盖全主动脉的4D流MRI。在后期处理过程中生成平面参数[反流分数（RF）、收缩期峰值速度（V）、总壁面切应力（WSS）]和节段参数[脉搏波速度（PWV）和粘性能量损失（VEL）]。采用Student's检验或Mann-Whitney检验比较三组之间的血流动力学。
共分析了11例TAAA患者（平均年龄53.2±11.9岁；10例男性）、19例AAA患者（平均年龄58.0±11.7岁；16例男性）和21例对照者（平均年龄55.4±15.0岁；19例男性）。与健康对照相比，TAAA患者主动脉弓处的RF显著更高，Vmax更低。TAAA患者的主动脉全长WSS较低，主要在肺动脉分叉平面和肾下中平面（所有P值<0.001）。至于节段血流动力学，与对照相比，TAAA患者胸主动脉的PWV显著更高（TAAA：中位数11.41 m/s，IQR 9.56 - 14.32 m/s；对照：中位数7.21 m/s，IQR 5.57 - 7.79 m/s；P<0.001），AAA患者也是如此（AAA：中位数8.75 m/s，IQR 7.35 - 10.75 m/s；对照：中位数7.21 m/s，IQR 5.57 - 7.79 m/s；P = 0.024）。此外，TAAA患者的全主动脉和腹主动脉观察到更大的VEL。
TAAA患者的主动脉壁更僵硬，全主动脉的WSS更低，VEL更大，同时主动脉扩张部分的RF更高，峰值速度更低。
