Wall Shear Stress Predicts Venous Tissue Growth in Endovascular Neural Interfaces

Area of Science:

• Biomedical Engineering
• Neurotechnology
• Vascular Biology

Background:

• Venous stents are used for obstruction and increasingly for endovascular neural interfaces in cerebral veins.
• Neointimal hyperplasia, thrombosis, and inflammation are challenges for long-term neural interface use in venous sinuses.

Purpose of the Study:

• To investigate the impact of venous stenting on blood flow and tissue growth in large venous sinuses.
• To understand the biomechanical environment influencing stent performance in cerebral veins.

Main Methods:

• Computational Fluid Dynamics (CFD) modeling.
• Animal experiments assessing blood flow and tissue responses over 28 days.

Main Results:

• A negative power law correlation was found between low wall shear stress (WSS) and accelerated tissue growth.
• Venous tissue growth after stenting showed greater variability compared to arteries.
• The threshold for low WSS triggering growth was lower in veins than previously reported for arteries.

Conclusions:

• Venous-specific responses, particularly neointimal hyperplasia driven by low WSS, must be considered in stent-electrode design for neural interfaces.
• Further investigation into thrombosis and inflammation is needed for long-term device viability.
• Understanding the biomechanics of venous stenting can guide the development of next-generation neural interfaces.