Analytical estimation of flow-induced forces in endovascular grafts and design methodology for a tissue-engineered endovascular attachment mechanism

摘要

Endovascular repair has emerged as an alternative, less-invasive surgical technique for the treatment of patients diagnosed with abdominal aortic aneurysms (AAAs). The anatomical pathway of blood flow in the abdominal aorta is restored by the implantation of an endovascular graft (EVG), depressurizing the aneurysm and initiating a remodeling process of the diseased aortic tissue. The short-term results of endovascular grafting are promising, but its long-term success has been compromised by the occurrence of graft migration or detachment, which induce endoleaks or incomplete occlusion of the aneurysm from the blood circulation. The forces induced by the blood as it flows through the graft are believed to be a factor of probable cause in the migration of the graft downstream and the partial detachment of its proximal and distal anchoring points. The purpose of this study is to utilize analytical tools to provide an estimation of the forces required to secure the graft proximally when relying on flow-induced stresses alone, and to describe the design methodology of a tissue-engineered proximal attachment mechanism that is capable of withstanding these forces. Composites of synthetic and native biodegradable polymers are examined as biomaterials for the attachment mechanism of the graft.