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Opis: Minimally invasive endovascular procedures are becoming a preferred approach to treat aortic dissection compared to traditional open surgery. Despite their advantages, endovascular options are currently limited to less complex geometries and are not without challenges. Endoleak, caused by the geometric mismatch between the straight cylindrical endograft and the curved aorta, remain a significant concern and lead to reinterventions. Understanding the underlying physical mechanisms governing the interfacial behavior of the seal zone is crucial to establishing guidelines for optimal stent sizing and developing more reliable endografts. Computational simulations are an essential tool in that regard, offering insights into the mechanical behavior of stents and aiding in their development. A computational study is performed to analyze the effects of endograft oversizing and artery curvature on potential endoleak. Based on identified mechanisms of endoleak creation, an optimal oversizing that minimizes potential endoleak is determined as a function of curvature. The findings will help develop new generations of endografts and define new standards. The Dissertation also involves computational modeling of a novel method to treat aortic arch dissection, where a bare metal stent is employed to expand the true lumen and displace the dissection flap. The simulation is compared to images from surgery, which shows a good agreement of the deformation patterns. An analysis of different dissection flap stiffnesses underscores the potential for this type of endovascular treatment if higher radial force can be provided by the stent. A methodology for lumen characterization is presented, based on which a personalized bare metal stent can be constructed for the aortic arch. Initial tailored stent designs indicate increased flap displacement compared to the original stent but encounter local instabilities at one of the support rings, which poses certain risks. Rectifying this design flaw is essential for advancing patient-specific bare metal stents, which hold the potential to revolutionize aortic arch dissection repair.
Ključne besede: endovascular aortic repair, TEVAR, vascular stent, endograft, aortic dissection, finite element analysis (FEA)
Objavljeno v DKUM: 17.10.2024; Ogledov: 0; Prenosov: 111
Celotno besedilo (73,27 MB)