Abstract 2009: Computational Modeling Of Long-term Aortic Root Dilatation Following TEVAR Of Type B Aortic Dissection

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Objectives: The long-term sequalae of thoracic endovascular aortic repair (TEVAR) are poorly understood. While several failure modes have been identified, the hemodynamic impact of TEVAR in the proximal native ascending aorta has yet to be fully appreciated. This study applies computational modeling tools to investigate a case of long-term aortic root dilatation following TEVAR for acute type B aortic dissection (TBAD). Methods: We investigate a patient who presented with heart failure 4.5 years after initially successful TEVAR. Cross-sectional aortic root diameter was measured in a pre-operative scan and 57 months post-TEVAR. Three-dimensional localized surface dilatation was calculated using pre-operative and post-operative segmentations, followed by a non-rigid surface mapping method of calculating area change in corresponding regions. The hemodynamic impact of TEVAR on the proximal aorta was analyzed with a computational fluid dynamics (CFD) simulation of the post-operative patient geometry. Results: Aortic root diameter increased from 39.2 mm pre-op to 47.1 mm (+ 20.1%) postop and 34.9 mm preop to 40.8 mm (+ 16.9%) postop on axial and coronal images respectively. The three-dimensional area mapping between pre and post-op scans demonstrates a maximum 14% area increase near the aortic root. The CFD simulations show increased velocity and static pressure in the ascending aorta near the aortic root region. Conclusions: Three different computational approaches demonstrate long-term changes in ascending aortic morphology following TEVAR. Computed tomography measurements demonstrate significant aortic root dilatation, and three-dimensional surface mapping shows increasing area in the proximal ascending aorta. The CFD results emphasize localization of increased velocity and stress in the same region. These observations point to potential avenues for further mechanistic investigation.