A Model Of Aortic Arch Stenting For Dissection Repair Using Finite Element Analysis And Computational Fluid Dynamics

Introduction: Treatment of residual aortic dissection following ascending arch repair remains clinically challenging. We propose a novel technique to stabilize the aortic arch and create a proximal seal zone by placement of a bare metal stent into the arch prior to thoracic endovascular aortic repair (TEVAR). Using finite element analysis and computational fluid dynamics, we assess if this technique achieves the desired technical result. Methods: We analyzed two patients at our institution, both of whom presented with residual arch and descending aortic dissection after ascending aortic repair. Pre-operative CT angiograms were segmented to create patient-specific 3D geometrical models of the dissected aorta. A tetrahedral mesh was derived from this model and subsequently used in a computational simulation of stent deployment in the aortic arch using finite element analysis. We then evaluated computational fluid dynamics of the stented aorta. Results: In silico deployment of an uncovered stent in the dissected aortic arch along the centerline of the true lumen was successfully achieved using our computational model of stent crimping and expansion. The model produced realistic results when compared to intra-operative fluoroscopic imaging. Minimal arterial damage was observed based on the stress and strain of the aortic wall. Computational fluid analysis demonstrated the presence of flow to the carotid and subclavian arteries, with areas of increased turbulence at the ostia as expected (Figure 1). Figure 1. Velocity streamlines representing blood flow following uncovered stent deployment in the aortic arch. Conclusions: Our in silico model shows feasibility of aortic arch stabilization using an uncovered stent to create a proximal seal zone for TEVAR while maintaining blood flow to branch vessels. Expected surgical outcomes can be computationally modeled using patient-specific geometries to allow for pre-operative planning and surgical risk assessment.