Alterations in wall shear stress predict sites of neointimal hyperplasia after stent implantation in rabbit iliac arteries
Alterations in wall shear stress predict sites of neointimal hyperplasia after stent implantation in rabbit iliac arteries
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DOI：
10.1152/ajpheart.01107.2004
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发表时间：
2005-05-01
影响因子：
4.8
通讯作者：
Pagel, PS
中科院分区：
文献类型：
--
作者：
LaDisa, JF;Olson, LE;Pagel, PS
新生内膜增生（NH）引起的再狭窄限制了血管内支架的有效性。再狭窄的发生率随支架的几何形状而变化，但支架是否影响体内壁面剪切应力（WSS）的时空分布尚不清楚。我们检验了支架植入后空间WSS的变化预测兔髂动脉NH位置的假设。在血管造影下行髂动脉顺行支架植入术，并于植入术后第14天、21天进行铸型前血流量测定。通过三维微焦X线计算机断层成像和动脉铸型重建获得髂动脉血流域。采用三维计算流体力学方法确定了WSS的各项指标。血管组织学在支架的近端和远端没有变化。时间相关的NH局限于支架区域，在暴露于低WSS和空间WSS梯度急性升高的区域最大。当NH发生在理论动脉的支架区域时，空间定位的WSS最低值在14天和21天后逐渐增加。这种NH消除了WSS分布的空间差异。结果表明，支架可能引入WSS的空间改变，从而调节体内的NH。
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.