Aneurysm Wall Stress and Tendency to Rupture are Features of Physical Wall Properties: An Experimental Study
Aneurysm Wall Stress and Tendency to Rupture are Features of Physical Wall Properties: An Experimental Study
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动脉瘤壁应力和破裂倾向是物理壁特性的特征：实验研究
DOI：
10.1177/152660280200900518
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发表时间：
2002
期刊：
影响因子：
--
通讯作者：
M. Adiseshiah
中科院分区：
文献类型：
--
作者：
H. S. Flora;B. Talei;L. Ansdell;E. Chaloner;A. Sweeny;A. Grass;M. Adiseshiah
目的：使用台式技术检查影响腹主动脉瘤 (AAA) 破裂风险（相对于动脉瘤囊物理特性）的生物物理现象。方法：在经过验证的脉动流模型 (PFM) 中测试了三种具有不同壁弹性的乳胶 AAA。将应变仪连接到每个 AAA 模型的颈部、拐点和最大直径处。在最初的研究中，评估了加压的影响和 AAA 壁应力的机械性能。在随后的研究中，使用管移植物排除乳胶 AAA，并在 PFM 中重新测试。创建已知尺寸和压力的 I 型或 II 型内漏后，测量全身/囊内压力和 AAA 壁应力。结果：每个模型都有一个复杂的壁应力模式，包括径向、纵向和剪切分量。在存在系统加压或内漏压力的情况下，任何点的峰值壁应力仅达到破坏强度的 1%。在具有加固墙的 AAA 中，峰值应力明显更大。统计分析表明，与增加 AAA 囊内的压力相比，壁强度对壁应力的影响更为显着。结论：AAA 壁力学对峰值壁应力的影响比系统内的压力变化更重要。特别是，刚度的增加（类似于胶原沉积）显着增加了峰值壁应力，该应力位于拐点而不是最大直径处。测量 AAA 壁力学和恶化速度的技术可以预测未治疗状态下或血管内修复后存在内漏的 AAA 破裂。
Purpose: To use bench top techniques to examine the biophysical phenomena affecting the risk of abdominal aortic aneurysm (AAA) rupture relative to the physical properties of the aneurysm sac. Methods: Three latex AAAs with different wall elasticities were tested in a validated pulsatile flow model (PFM). Strain gauges were wired to each AAA model at the neck, inflection point, and at the maximum diameter. In initial studies, the influence of pressurization and the mechanical properties of AAA wall stress were evaluated. In subsequent studies, the latex AAAs were excluded with a tube graft and retested in the PFM. After creation of either a type I or II endoleak of known size and pressure, the systemic/intrasac pressure and the AAA wall stress were measured. Results: Each model had a complex wall-stress pattern comprising radial, longitudinal, and shear components. The peak wall stress at any point, in the presence of systemic pressurization or endoleak pressure, only reached 1% of the failure strength. In an AAA with a reinforced wall, the peak stress was significantly greater. Statistical analysis showed that wall strength contributed more significantly to wall stress than increasing pressurization within the AAA sac. Conclusions: AAA wall mechanics contribute more significantly to peak wall stress than pressure variations within the system. In particular, increased stiffness (analogous to collagen deposition) significantly increased peak wall stress, which was located at the inflection point rather than at the maximum diameter. Techniques to measure the AAA wall mechanics and the rate of deterioration may predict AAA rupture in the untreated state or in the presence of an endoleak following endovascular repair.