Numerical Simulations of In-Plane and Transmural Tear Propagations in Aortic Dissection: Possible Mechanisms Behind...

Area of Science:

• Biomedical Engineering
• Computational Mechanics
• Cardiovascular Research

Background:

• Aortic dissection (AD) progression involves tear propagation, crucial for surgical planning.
• Mechanisms of early tear propagation in AD remain poorly understood.
• Understanding tear dynamics is key to predicting AD outcomes.

Purpose of the Study:

• To model and analyze the mechanisms of early tear propagation in aortic dissections.
• To investigate the interplay between in-plane and transmural tear propagation.
• To identify factors influencing dissection progression.

Main Methods:

• Utilized the cohesive zone method for interface damage (in-plane propagation).
• Employed a strain-energy-based criterion for bulk material damage (transmural propagation).
• Developed a 3D finite-element model of an idealized aorta with geometrical parameter analysis.

Main Results:

• Critical pressures for in-plane propagation are within physiological blood pressure ranges.
• In-plane propagation is initially favored but transmural propagation dominates at higher pressures.
• Geometrical thresholds and tear size significantly influence critical pressures for both propagation modes.

Conclusions:

• Successfully integrated interface and bulk damage models to simulate AD tear propagation.
• Identified key mechanisms driving dissection progression.
• Findings offer insights for predicting AD development and guiding treatment strategies.