Karlsson Jerker, Stålhand Jonas, Carlhäll Carl-Johan, Länne Toste, Engvall Jan
Department of Clinical Physiology in Linköping, Department of Health, Medicine and Caring Sciences, Linköping University, Linköping, Sweden.
Solid Mechanics, Department of Management and Engineering, Linköping University, Linköping, Sweden.
Front Physiol. 2023 Mar 13;14:1128131. doi: 10.3389/fphys.2023.1128131. eCollection 2023.
Wall stress of the abdominal aorta (AA) appears to be an important factor in the assessment of risk for rupture based on the relationship between blood pressure and aortic diameter. We therefore investigated peak wall stress as well as isotropic and anisotropic wall stress of AA. Thirty healthy adults (male = 15) were included. Pulsatile diameter changes were determined non-invasively by an echo-tracking system, and intra-aortic pressure was measured simultaneously. A computer based mechanical model was used to compute the isotropic and anisotropic components of circumferential and longitudinal stresses. Elderly males had higher total wall stress and a higher isotropic stress component in the circumferential direction and higher total longitudinal wall stress than elderly females. The isotropic component increased with age in males but not in females, whereas the anisotropic component decreased with age in both sexes. We found that isotropic and anisotropic properties of the abdominal aortic wall differ between young and elderly participants and between the sexes. A possible explanation could relate to chemical alterations (e.g., due to sex hormones) and changes over time in the physical distribution of fibers. Modeling of wall stress components of the human AA may contribute to a better understanding of elastin-collagen interactions during remodeling of the aortic wall.
基于血压与主动脉直径之间的关系，腹主动脉（AA）的壁应力似乎是评估破裂风险的一个重要因素。因此，我们研究了腹主动脉的峰值壁应力以及各向同性和各向异性壁应力。纳入了30名健康成年人（男性15名）。通过回声跟踪系统非侵入性地测定搏动性直径变化，并同时测量主动脉内压力。使用基于计算机的力学模型来计算周向和纵向应力的各向同性和各向异性分量。老年男性的总壁应力较高，周向方向的各向同性应力分量较高，总纵向壁应力也高于老年女性。男性的各向同性分量随年龄增加，而女性则不然，而各向异性分量在两性中均随年龄下降。我们发现，年轻和老年参与者之间以及男性和女性之间腹主动脉壁的各向同性和各向异性特性存在差异。一个可能的解释可能与化学改变（例如，由于性激素）以及纤维物理分布随时间的变化有关。对人体腹主动脉壁应力分量进行建模可能有助于更好地理解主动脉壁重塑过程中弹性蛋白 - 胶原蛋白的相互作用。
