Coupling poroelasticity and CFD for cerebrospinal fluid hydrodynamics

Area of Science:

• Biomedical Engineering
• Computational Science
• Fluid Dynamics

Background:

• Hydrocephalus is a condition characterized by the abnormal accumulation of cerebrospinal fluid (CSF) within the brain's ventricles.
• Stenosis of the cerebral aqueduct is a common cause of obstructive hydrocephalus, leading to increased intracranial pressure.
• Previous models often simplify the complex biomechanical interactions within the ventricular system.

Purpose of the Study:

• To investigate the impact of cerebral aqueduct stenosis on acute hydrocephalus.
• To explore the role of fluidic-poroelastic coupling in ventricular enlargement.
• To analyze the influence of stenosis patterns on cerebrospinal fluid dynamics and pressure gradients.

Main Methods:

• Coupling poroelastic theory with multidimensional computational fluid dynamics (CFD) simulations.
• Developing a computational model of the cerebral aqueduct and ventricular system.
• Simulating various physically relevant stenosis patterns.

Main Results:

• Ventricular enlargement is significantly reduced with localized stenosis patterns.
• The fluidic-poroelastic coupling plays a critical role in determining the extent of ventricular enlargement.
• The majority of the pressure drop occurs across the stenosis, highlighting its localized impact.
• Short-timescale effects, such as those related to heartbeat, were explored in relation to long-term responses.

Conclusions:

• The interplay between fluid flow and tissue mechanics (poroelasticity) is essential for accurately modeling hydrocephalus.
• Localized stenosis patterns have a less severe impact on ventricular enlargement compared to diffuse patterns.
• Computational modeling provides novel insights into the complex dynamics of cerebrospinal fluid regulation in hydrocephalus.