Assessment of Aortic Dissection Remodeling With Patient-Specific Fluid-Structure Interaction Models

Area of Science:

• Cardiovascular research
• Biomedical engineering
• Medical imaging analysis

Background:

• Aortic dissection can cause chronic degeneration and dilatation of the false lumen, leading to late complications.
• Understanding the interplay between hemodynamics and aortic remodeling is crucial for managing aortic dissection.

Purpose of the Study:

• To investigate the relationship between hemodynamics and long-term aortic dissection remodeling.
• To analyze the progression of aortic dilatation and morphological changes from pre-dissection to the chronic phase.

Main Methods:

• Utilized CT angiography for tracking patient's aortic dissection over time.
• Employed fluid-structure interaction models incorporating tissue prestress, external support, and anisotropic properties.
• Defined boundary conditions using in vitro 4D-flow MRI and patient's blood pressure data.

Main Results:

• Aortic dilatation was most pronounced distal to the left subclavian artery, reaching 6 cm in the chronic phase.
• Flow jet velocity through the entry tear decreased from 185 cm/s (subacute) to 123-133 cm/s (chronic), correlating with increased tear size.
• Localized pressure increases and wall shear stress were observed due to flow jet impingement, indicating hemodynamic drivers of aortic growth.

Conclusions:

• Hemodynamic changes are identified as primary drivers of aortic growth and morphological alterations in dissection.
• Increased in-plane flap displacement correlated with overall aortic diameter increase.
• While based on a single patient, findings suggest a strong link between hemodynamics and aortic remodeling in dissection.