An In Vitro Study of Embolus Migration in an Anatomical Cerebrovascular Model

Area of Science:

• Biomedical Engineering
• Fluid Dynamics
• Neurology

Background:

• Acute ischemic stroke (AIS) is a leading cause of death and disability.
• Embolus migration to the brain is critical in AIS, but mechanisms are poorly understood.
• Computational models for AIS lack validation due to limited experimental data.

Purpose of the Study:

• To gather experimental data on embolus migration in a realistic aortic and cerebrovascular model.
• To investigate the influence of embolus size, deformability, and fluid rheology on migration patterns.
• To provide benchmark data for validating computational models of AIS.

Main Methods:

• In vitro experiments using a pulsatile flow model of the aorta and cerebrovasculature.
• Testing of rigid spheres (1.58-4.76 mm) and deformable blood clots (2.53-3.95 mm).
• Use of Newtonian and non-Newtonian blood analogs to assess rheology effects.

Main Results:

• Smaller emboli showed a higher tendency to migrate into cerebrovasculature.
• Deformable blood clots migrated more readily to supra-aortic branches than rigid spheres of similar size.
• Fluid rheology had minimal impact on deformable emboli partitioning but slightly affected rigid sphere migration.

Conclusions:

• Embolus deformability is a more critical factor than rheology in determining cerebral circulation migration.
• Accurate prediction of AIS embolus trajectories requires models incorporating fluid-structure interactions and clot deformability.