STENT-INDUCED ARTERIAL FLOW DISTURBANCE - WHOLE VESSEL AND CELLULAR CONSIDERATIONS

摘要

Although the use of endovascular stents has significantly reduced the incidence of restenosis following balloon angioplasty, restenosis rates remain unacceptably high (20-35% of all angioplasty procedures) Placement of a stent within an arterial segment locally injures vascular endothelium thereby stimulating thrombotic responses that contribute to the development of in-stent restenosis. Recent research suggests that the local fluid mechanical environment in the vicinity of a stent impacts the rate of vessel re-endothelialization following stent-induced injury. This is supported by in vitro data demonstrating that endothelial repair after injury is sensitive to fluid mechanical forces. Recent in vivo data suggest that in-stent restenosis preferentially develops in arterial regions exposed to low and/or oscillatory shear stress. Therefore, it is essential to establish the detailed flow environment in the vicinity of a stent and to investigate the impact of this environment on EC function. The present study uses computational fluid dynamics (CFD) to probe the occurrence of stent-induced arterial flow disturbance under both steady and pulsatile flow conditions. Whole-cell patch-clamp recordings on cultured ECs are used to investigate the impact of disturbed flow on cell membrane potential. Cell membrane potential, through its effect on intracellular Ca~(2+) levels, regulates various processes essential for EC healing following injury including cell spreading, migration, and proliferation.