Macro- and microscale variables regulate stent haemodynamics, fibrin deposition and thrombomodulin expression

Area of Science:

• Biomedical Engineering
• Cardiovascular Research
• Fluid Dynamics

Background:

• Drug-eluting stents (DES) are linked to late stent thrombosis (LST) and delayed healing.
• Stent strut exposure to blood flow can initiate prothrombotic conditions.

Purpose of the Study:

• To investigate how microscale stent strut geometry affects prothrombotic conditions under various fluid flow conditions.
• To determine the impact of strut design on fibrin deposition and endothelial thrombomodulin (TM) expression.

Main Methods:

• Numerical simulations of fluid flow dynamics around different stent strut geometries.
• Experimental particle flow visualization to observe recirculation zones and fibrin deposition.
• Assessment of endothelial thrombomodulin (TM) expression in relation to strut design.

Main Results:

• Stent strut geometry and bulk fluid flow interact to regulate peristrut flow recirculation zones.
• Thinner and streamlined strut designs significantly reduced recirculation zones and fibrin deposition.
• Reduced recirculation correlated with increased endothelial anticoagulant TM expression.

Conclusions:

• Microscale strut geometry is a critical factor in stent thrombogenicity.
• Optimizing stent strut design (thinner, streamlined) can mitigate LST risk and improve healing.
• Findings provide insights into physical and functional consequences influencing current stent designs and LST.