Hemodynamics Simulation of Aortic Arch Aneurysm with Partly Bridged Endovascular Stent

Abstract

Endovascular stents are one of the minimally invasive modern techniques for the treatment of aortic arch aneurysms. With the implantation of stent bridging the aneurysmal orifice, the side branches at the aortic arch may be covered by the stent filaments, which will influence the blood perfusion to these branches. We propose a novel approach to stenting treatment for aortic arch aneurysms with partly bridged endovascular stent to avoid the abovementioned situation. The objectives of the study were to construct a nonstented, a fully stented and a partly stented aortic arch aneurysm models harboring blebs on their domes, demonstrate the detailed flow patterns, pressure and wall shear stress distributions around the aneurysm, and examine whether partly stented aneurysms have preferable intra-aneurysmal hemodynamics for thrombus and occlusion. The physiologic blood flows around the aortic arch aneurysms were simulated using the method of computational fluid dynamics. The hemodynamics in the three designed models were analyzed and compared. The simulation results showed substantial differences in flow patterns between the stented and nonstented models inside the aneurysmal sacs. However, the fully stented and the partly stented models feature similar hemodynamics. Flow activities inside the partly stented aneurysm model were also significantly diminished, specifically the pressures and wall shear stresses in the bleb were decreased, thus promoting intra-aneurysmal thrombus development and attenuating aneurysm rupture risk. The present simulation study indicated that partly bridged endovascular stents seem to offer a feasible technique in the effective treatment of aortic arch aneurysms.