Li Z, Kleinstreuer C
Department of Mechanical and Aerospace Engineering, North Carolina State University, Raleigh 27695-7910, USA.
J Med Eng Technol. 2006 Sep-Oct;30(5):283-97. doi: 10.1080/03091900500217406.
Sudden rupture of abdominal aortic aneurysm (AAA), often without prior medical warning, is the 13th leading cause of mortality in the US. The local rupture is triggered when the elusive maximum local wall stress exceeds the patient's yield stress. Employing a validated fluid-structure interaction code, the coupled blood flow and AAA wall dynamics were simulated and analysed for two representative asymmetric AAAs with different neck angles and iliac bifurcations. It turned out that the AAA morphology plays an important role in wall deformation and stress distribution, and hence possible rupture. The neck angle substantially impacts flow fields. A large neck angle may cause strong irregular vortices in the AAA cavity and may influence the wall stress distribution remarkably. The rupture risk of lateral asymmetric AAAs is higher than for the anterior-posterior asymmetric types. The most likely rupture site is located near the anterior distal side for the anterior-posterior asymmetric AAA and the left distal side in the lateral asymmetric AAA.
腹主动脉瘤（AAA）突然破裂，通常没有先前的医学预警，是美国第13大致死原因。当难以捉摸的最大局部壁面应力超过患者的屈服应力时，就会引发局部破裂。采用经过验证的流固耦合代码，对具有不同颈部角度和髂动脉分叉的两个代表性不对称腹主动脉瘤的血流与腹主动脉瘤壁动力学进行了模拟和分析。结果表明，腹主动脉瘤形态在壁变形和应力分布以及因此可能发生的破裂中起着重要作用。颈部角度对流场有显著影响。大的颈部角度可能会在腹主动脉瘤腔内引起强烈的不规则涡流，并可能显著影响壁应力分布。横向不对称腹主动脉瘤的破裂风险高于前后不对称类型。前后不对称腹主动脉瘤最可能的破裂部位位于前远端附近，而横向不对称腹主动脉瘤的最可能破裂部位位于左远端。
