Bicuspid aortic valve aortopathies: An hemodynamics characterization in dilated aortas

Abstract

Bicuspid aortic valve (BAV) aortopathy remains of difficult clinical management due to its heterogeneity and further assessment of related aortic hemodynamics is necessary. The aim of this study was to assess systolic hemodynamic indexes and wall stresses in patients with diverse BAV phenotypes and dilated ascending aortas. The aortic geometry was reconstructed from patient-specific images while the aortic valve was generated based on patient-specific measurements. Physiologic material properties and boundary conditions were applied and fully coupled fluid-structure interaction (FSI) analysis were conducted. Our dilated aortic models were characterized by the presence of abnormal hemodynamics with elevated degrees of flow skewness and eccentricity, regardless of BAV morphotype. Retrograde flow was also present. Both features, predicted by flow angle and flow reversal ratios, were consistently higher than those reported for non-dilated aortas. Right-handed helical flow was present, as well as elevated wall shear stress (WSS) on the outer ascending aortic wall. Our results suggest that the abnormal flow associated with BAV may play a role in aortic enlargement and progress it further on already dilated aortas.

Keywords:

• aortic dilation
• aorthopathy
• bicuspid aortic valve
• fluid-structure interaction

Disclosure statement

No potential conflict of interest was reported by the authors.

Additional information

Funding

The partial financial support from the Portuguese FCT - Fundação para a Ciência e a Tecnologia through the grant SFRH/BPD/109574/2015, the project UID/Multi/04621/2013 of the CEMAT - Center for Computational and Stochastic Mathematics, Instituto Superior Técnico, University of Lisbon, Portugal and the UT Austin—Portugal Program (Advanced Computing) are deeply acknowledged.