Title

Alterations in Wall Shear Stress Predict Sites of Neointimal Hyperplasia after Stent Implantation in Rabbit Iliac Arteries

Document Type

Article

Language

eng

Format of Original

11 p.

Publication Date

5-2005

Publisher

American Physiological Society

Source Publication

American Journal of Physiology - Heart and Circulatory Physiology

Source ISSN

0363-6135

Original Item ID

doi: 10.1152/ajpheart.01107.2004

Abstract

Restenosis resulting from neointimal hyperplasia (NH) limits the effectiveness of intravascular stents. Rates of restenosis vary with stent geometry, but whether stents affect spatial and temporal distributions of wall shear stress (WSS) in vivo is unknown. We tested the hypothesis that alterations in spatial WSS after stent implantation predict sites of NH in rabbit iliac arteries. Antegrade iliac artery stent implantation was performed under angiography, and blood flow was measured before casting 14 or 21 days after implantation. Iliac artery blood flow domains were obtained from three-dimensional microfocal X-ray computed tomography imaging and reconstruction of the arterial casts. Indexes of WSS were determined using three-dimensional computational fluid dynamics. Vascular histology was unchanged proximal and distal to the stent. Time-dependent NH was localized within the stented region and was greatest in regions exposed to low WSS and acute elevations in spatial WSS gradients. The lowest values of WSS spatially localized to the stented area of a theoretical artery progressively increased after 14 and 21 days as NH occurred within these regions. This NH abolished spatial disparity in distributions of WSS. The results suggest that stents may introduce spatial alterations in WSS that modulate NH in vivo.

Comments

American Journal of Physiology - Heart and Circulatory Physiology, Vol. 288, No. 5 (May 2005): H2465-H2475. DOI.