Ning Hongxia, Liu Xiaozheng, Ma Chunyan, Yang Jun, Li Tan
Department of Cardiovascular Ultrasound, The First Hospital of China Medical University, Shenyang, Liaoning Province, China.
J Ultrasound Med. 2022 May;41(5):1085-1093. doi: 10.1002/jum.15792. Epub 2021 Jul 23.
Abdominal aortic aneurysm (AAA) is a dangerous and lethal vascular disease. Non-invasive two-dimensional speckle-tracking imaging (2D STI) plays an important role in assessing aortic biomechanical properties. Our study aimed to evaluate the alterations of biomechanical characteristics using 2D STI in 91 AAA patients with different size.
Aneurysm strain, elastic modulus, stiffness index β, and aortic distensibility determined by M-Mode ultrasound (US), and longitudinal strain (LS) derived from 2D STI were compared in 40 large AAA patients (diameter ≥ 55 mm) and 51 small AAA patients (diameter < 55 mm).
Compared with small AAA group, anterior wall longitudinal strain (ALS) and posterior wall longitudinal strain (PLS) were significantly decreased in large AAA group (all P < .05) and not affected by age, symptom, hypertension, and thrombus. Meanwhile, ALS and PLS correlated negatively with maximal aneurysm diameters (r = -0.628 and -0.469, respectively, all P < .001). And only ALS was associated with M-Mode US parameters (all P < .05). Based on receiver operating characteristic (ROC) analysis, ALS and PLS had strong diagnostic values for large AAA with the area under the curve (AUC) of 0.82 and 0.72, and cut-off points of 1.71 and 1.64% with a sensitivity of 78 and 72%, and a specificity of 75 and 70%, respectively.
LS measured by 2D STI could evaluate the biomechanical properties of aneurysm wall with different size, and add additional diagnostic value in distinguishing between small and large AAA.
腹主动脉瘤（AAA）是一种危险且致命的血管疾病。非侵入性二维斑点追踪成像（2D STI）在评估主动脉生物力学特性方面发挥着重要作用。我们的研究旨在使用2D STI评估91例不同大小的AAA患者的生物力学特征变化。
比较了40例大AAA患者（直径≥55 mm）和51例小AAA患者（直径<55 mm）的动脉瘤应变、弹性模量、硬度指数β以及通过M型超声（US）测定的主动脉扩张性，以及从2D STI得出的纵向应变（LS）。
与小AAA组相比，大AAA组的前壁纵向应变（ALS）和后壁纵向应变（PLS）显著降低（均P<0.05），且不受年龄、症状、高血压和血栓的影响。同时，ALS和PLS与最大动脉瘤直径呈负相关（r分别为-0.628和-0.469，均P<0.001）。并且只有ALS与M型超声参数相关（均P<0.05）。基于受试者工作特征（ROC）分析，ALS和PLS对大AAA具有较强的诊断价值，曲线下面积（AUC）分别为0.82和0.72，截断点分别为1.71%和1.64%，灵敏度分别为78%和72%，特异性分别为75%和70%。
通过2D STI测量的LS可以评估不同大小动脉瘤壁的生物力学特性，并在区分小AAA和大AAA方面增加额外的诊断价值。
