Elevated Blood Viscosity and Microrecirculation Resulting From Coronary Stent Malapposition

Area of Science:

• Cardiovascular Research
• Biomedical Engineering
• Computational Fluid Dynamics

Background:

• Coronary arteries naturally taper, leading to incomplete stent apposition (ISA).
• ISA can alter blood flow dynamics, increasing risks of in-stent restenosis and stent thrombosis.
• Understanding these hemodynamic changes is crucial for improving stent design and patient outcomes.

Purpose of the Study:

• To investigate the impact of natural coronary artery tapering on stent malapposition and hemodynamics.
• To analyze the development of microrecirculation environments and their effect on wall shear stress (WSS) and blood viscosity.
• To provide a deeper physical explanation for tissue accumulation near malapposed stent struts.

Main Methods:

• Utilizing computer-aided design (CAD) to model stent deployment in a tapered coronary artery.
• Performing pulsatile blood flow simulations using computational fluid dynamics (CFD).
• Analyzing spatial and temporal changes in microrecirculation, WSS, and blood viscosity.

Main Results:

• CFD simulations revealed detailed spatial and temporal development of microrecirculation due to tapering and ISA.
• Arterial tapering induced secondary microrecirculation, causing significant fluctuations in WSS.
• Microrecirculations influenced local blood viscosity near malapposed stent struts, potentially explaining tissue accumulation.

Conclusions:

• Natural coronary artery tapering significantly impacts stent deployment and hemodynamics, creating complex microrecirculation patterns.
• Fluctuations in WSS and altered blood rheology in microrecirculation zones are linked to ISA complications.
• These findings offer new insights into the mechanisms underlying stent-related issues and tissue accumulation.