Recent Patents of Stent Grafts for Intravascular Aortic Repair.

Abstract

Introduction: Endovascular aortic repair involves the placement of stents through minimally invasive methods to seal rupture sites near the aortic inflow tract, thereby preventing blood entry into the false lumen and promoting thrombosis, which reduces the risk of aortic rupture. Endovascular stents typically consist of a metal framework and a flexible membrane graft designed to reopen obstructed aortic segments and maintain blood flow through the true lumen. Consequently, stents are widely used to treat aortic expansion diseases and aortic occlusive stenosis. However, traditional stents have limitations in terms of adaptability to complex anatomical structures, long-term durability, biomechanical stability, and reliance on radial support force for fixation, lacking active fixation mechanisms. These shortcomings remain the primary causes of postoperative complications, significantly impacting the quality of life for patients with aortic dissection.

Methods: The research status of the endovascular stent was discussed in depth, and the main factors for the optimal design of the stent (geometry, pattern configuration, additional fixtures, and optimization methods) were analyzed and summarized according to the complications targeted by the repair device.

Results: The composition structure, working principle, and development status of the stent grafts under review are elaborated in detail. Stent grafts attempt to alleviate postoperative complications through three approaches: enhancing the flexibility of the stent framework, improving the fit between the vessel wall and the stent, and reducing vascular injury. Blood flow guiding channels are established to alleviate the obstruction of branch blood flow. Additional self-anchoring devices are added to adapt to the dynamic remodeling of blood vessels.

Discussion: The effects of various factors, including geometric parameters, structural design, and parameter optimization techniques, on the optimization of stent primary mechanical performance are discussed. The current research status of functional improvement methods for stents is also summarized.

Conclusion: Refining the quantitative relationship between stent structural parameters and mechanical performance, as well as exploring the balance criteria between flexibility and radial support force, represent promising directions for future development. These objectives necessitate further in-depth analysis and research.