Hemodynamic studies of flow modulating stent designs for aortic aneurysms

Abstract

Aortic aneurysms are localized dilatation of 50% greater than normal diameter of the aorta. In United States alone, about 5% to 7% of people aged 60 and above have aortic aneurysm. Left untreated, the aneurysm will rupture and carries a risk of death up to 90%. Conventional treatment options available include surgical repair and graft replacement, resulted in frequent major morbidity and death. Over the years, surgical intervention has evolved with the introduction of minimally invasive endovascular repair with lower mortality and morbidity risks. Endovascular aortic repair device consists of stent graft composed of fabric or polymer material supported by a metal mesh stent. These covered stent grafts excludes the aneurysmal aorta from the blood flow thereby causing the aneurysm sac thrombosis. The shortcomings of current stent grafts of maintaining blood flow to branches and collateral vessels have lead to the development of flow modulating stent grafts. Flow modulating stent grafts preserved blood flow to the side vessels and thereby avoid risk of visceral ischemia. This study investigates the flow behavior of variety of flow modulating stent designs in treating aortic aneurysm. The study highlights the hemodynamics flow within the aneurysm as a result of the flow modulating stent designs. The hemodynamics flow study of the emerging flowmodulating stent technology in an aneurysm is analyzed using computational fluid dynamics simulation.