颈动脉支架置入后的血流动力学改变

Changes in hemodynamics following carotid stent implantation

颈动脉支架置入可有效改善脑血流灌注,改善狭窄段血流速度,被认为是治疗颈动脉狭窄的有效方法之一。但由于球囊扩张、支架置入机械扩张和牵拉,颈动脉窦引起内膜和动脉粥样硬化斑块的表面撕裂,调整了颈动脉壁顺应性,改变了颈动脉受体的敏感性,引起血液动力学不稳定和斑块碎片脱落,引起低血压、心动过缓、高血压及血管栓塞等并发症,如何控制和减少上述并发症的发生是目前研究的主要问题。选择相对柔软的,侧弯性能较好,且直径应比狭窄处实测直径大1.0～2.0mm的支架,提高置入操作技术,可以减轻支架置入过程中球囊扩张及支架膨胀时对粥样斑块的挤压与切割作用,防止斑块脱落,同时使用滤器脑保护装置以过滤较大组织碎片,阻止较大微栓子进入脑循环,提高颈动脉支架置入的安全性。

Carotid stent implantation effectively improves cerebral blood flow perfusion and blood flow rate of stenotic segment. This method has been considered one of effective methods for treating carotid artery stenosis. Surface tear of the endomembrane and atherosclerotic plaque induced by balloon dilatation, mechanical expansion and carotid sinus draw-off can adjust compliance of the carotid wall, change sensitiveness of carotid artery receptor, cause instability of hemadynamics and defluxion of plaque fragments, lead to hypotension, bradycardia, hypertension and vascular embolism. How to control and reduce occurrence of above-mentioned complications is a main problem in present studies. Stent should be soft, with good lateral bending property, and diameter of the stent should be 1.0-2.0 mm longer than the actual stenosis. Implantation technique should be improved. These can reduce extrusion and cutting action of the atheromatous plaque due to balloon dilatation and stent expansion, and prevent plaque defluxion during implantation. Filter protection device is used to filter tissue debris and to prevent microemboli entering cerebral circulation, which can elevate safety of carotid stent implantation.