Modeling the Mechanical Microenvironment of Coiled Cerebral Aneurysms

Area of Science:

• Biomedical Engineering
• Fluid Dynamics
• Neurosurgery

Background:

• Successful cerebral aneurysm treatment via coil embolization relies on stable thrombus formation.
• The biomechanical environment within the aneurysm critically influences thrombus quality.

Purpose of the Study:

• To investigate how coil embolization modifies the mechanical micro-environment within the aneurysm dome.
• To understand the impact of altered biomechanics on thrombus formation.

Main Methods:

• Utilized 3D computational simulations of blood flow in patient-specific aneurysms.
• Simulated coil embolization as a porous medium with defined permeability and inertial constant.
• Employed Lagrangian particle tracking to analyze particle residence time and shear stress history pre- and post-treatment.

Main Results:

• A decrease in particles entering the aneurysm dome post-treatment correlated with neck surface area and coil packing density.
• Particles with longer residence times accumulated lower shear stress within the dome.
• A significant correlation was found between changes in residence time and the neck surface area to porosity ratio.

Conclusions:

• Coil embolization induces clot formation within the aneurysm dome through a low shear stress pathway.
• This finding provides a mechanistic link between computational fluid dynamics and clinical observations in aneurysm treatment.
• The study enhances understanding of the biomechanical factors governing successful coil embolization outcomes.