Cardiovascular Biomechanics Group, Department of Biomedical Engineering, Eindhoven University of Technology, P.O. Box 513, MB Eindhoven, The Netherlands.
Department of Surgery, Catharina Hospital Eindhoven, ZA Eindhoven, The Netherlands.
Eur Heart J Cardiovasc Imaging. 2019 Feb 1;20(2):185-191. doi: 10.1093/ehjci/jey051.
Using non-invasive 3D ultrasound, peak wall stress (PWS) and aortic stiffness can be evaluated, which may provide additional criteria in abdominal aortic aneurysm (AAA) risk assessment. In this study, these measures were determined in both young and age-matched individuals, and AAA patients while its relation to age, maximum diameter, and growth was assessed statistically.
Time-resolved 3D-US data were acquired for 30 volunteers and 65 AAA patients. The aortic geometry was segmented, and tracked over the cardiac cycle using 3D speckle tracking to characterize the wall motion. Wall stress analysis was performed using finite element analysis. Model parameters were optimized until the model output matched the measured 3D displacements. A significant increase in aortic stiffness was measured between the age-matched volunteers [median 0.58, interquartile range (IQR) 0.48-0.71 kPa⋅m] and the small AAA patients (median 1.84, IQR 1.38-2.46 kPa⋅m; P < 0.001). In addition, an increase in aortic stiffness was evaluated between the small (30-39 mm) and large (≥50 mm) AAAs (median 2.72, IQR 1.99-3.14 kPa⋅m; P = 0.01). The 99th percentile wall stress showed a positive correlation with diameter (ρ = 0.73, P < 0.001), and significant differences between age-matched volunteers and AAA patients.
The AAA pathology causes an early and significant increase in aortic stiffness of the abdominal aorta, even after correcting for the expected effect of ageing and differences in arterial pressure. Moreover, some AAAs revealed relatively high PWS, although the maximum diameter was below the threshold for surgical repair. Using the current method, these measures become available during follow-up, which could improve AAA rupture risk assessment.
使用非侵入性的 3D 超声，可以评估峰值壁应力（PWS）和主动脉僵硬度，这可能为腹主动脉瘤（AAA）风险评估提供额外标准。在这项研究中，我们在年轻和年龄匹配的个体以及 AAA 患者中确定了这些指标，并评估了它们与年龄、最大直径和生长的关系。
为 30 名志愿者和 65 名 AAA 患者采集了时分辨 3D-US 数据。使用 3D 斑点追踪技术对主动脉几何形状进行分割，并在心脏周期内进行跟踪，以对壁运动进行特征描述。使用有限元分析进行壁应力分析。优化模型参数，直到模型输出与测量的 3D 位移匹配。在年龄匹配的志愿者（中位数 0.58，四分位距（IQR）0.48-0.71 kPa·m）和小 AAA 患者（中位数 1.84，IQR 1.38-2.46 kPa·m；P < 0.001）之间，主动脉僵硬度显著增加。此外，在小（30-39mm）和大（≥50mm）AAA 之间评估了主动脉僵硬度的增加（中位数 2.72，IQR 1.99-3.14 kPa·m；P = 0.01）。第 99 百分位壁应力与直径呈正相关（ρ=0.73，P < 0.001），并且与年龄匹配的志愿者和 AAA 患者之间存在显著差异。
AAA 病理导致腹主动脉的主动脉僵硬度早期且显著增加，即使校正了预期的老化和动脉压差异的影响也是如此。此外，尽管最大直径低于手术修复的阈值，但一些 AAA 显示出相对较高的 PWS。使用当前方法，这些指标可在随访期间获得，这可能会改善 AAA 破裂风险评估。
