Effect Of Angioplasty And Stenting On Cerebrovascular Reserve

Background and objectiveDuring the last 2 decades, percutaneous transluminal angioplasty and stent placement have become a therapeutic alternative to carotid endarterectomy (CEA) in the treatment of carotid stenosis. Although both the risk and benefit of carotid angioplasty stent(CAS) have been studied, little is known about hemodynamic changes after CAS. The hemodynamic changes in the middle cerebral artery (MCA) flow velocity after CAS have been less studied. Cerebral hemodynamics can be evaluated by transcranial Doppler (TCD). This simple noninvasive technique provides information on blood flow velocities in larger cerebral vessels and has proved to be reliable to evaluate the cerebrovascular reserve(CVR) which means the capability of cerebral blood flow increases after stimulus.The purpose of this study was to determine whether the Cerebrovascular Reserve in patients with severe Carotid stenosis impaired,Carotid angioplasty and stenting can benefit the impaired cerebrovascular reserve.MethodsThe study was divided into two parts:1. 60 patients with severe Carotid stenosis(stenosis≥70 % ) and 60 senile volunteers,who came from Xinqiao hospital,Third Military Medical University,in the same period,were enrolled in the study. Transcranial Doppler examination were used to evaluate their cerebrovascular reserve , and to estimate the effect of Carotid stenosis on Cerebrovascular Reserve.2. Sixty patients underwent carotid angioplasty and stenting for≥70% internal carotid artery stenosis. Transcranial Doppler was done before, and 30 days after. Cerebrovascular reserve to apnea was measured to estimate the Effect of Angioplasty and Stenting on Cerebrovascular Reserve.Results1. Evaluating the Cerebrovascular Reserve in patients with severe Carotid stenosis compared with the control: Comparing the severe Carotid stenosis group with the control group: the Cerebrovascular Reserve of stenotic side in severe Carotid stenosis patients is significant lower(P<0.05).However, the contralateral cerebrovascular reserve Carotid stenosis patients is lower,but without significant changes(P>0.05).2. Evaluating the Cerebrovascular Reserve of stenotic side in patients with severe Carotid stenosis compared with the contralateral side, Comparing the stenotic side with the contralateral side: the Cerebrovascular Reserve of stenotic side in severe Carotid stenosis patients is significant lower(P<0.05).3. 60 patients with a mean stenosis diameter of 85.2%±7.5%, including 20 patients with 70%-89% stenosis ,33 patients with 90%-95% stenosis,and 7 patients with 95%-99% stenosis.The Residual Stenosis After CAS is less than 30%.4. Evaluating the Cerebrovascular Reserve in diabetes mellitus group compared with the non-diabetes mellitus group: the Cerebrovascular Reserve of stenotic side in diabetes mellitus group is significant lower(P<0.05).5. Evaluating the Cerebrovascular Reserve in patients with severe Carotid stenosis after CAS 30 days compared with before operation , Basal ipsilateral and contralateral cerebrovascular reserve improved from 18.3% to 30.3% (P<0 .05), and from 28.6% to 31.6%(P>0.05), respectively, at 30 days.6. After CAS 30 days , evaluating the Cerebrovascular Reserve in diabetes mellitus group compared with the non-diabetes mellitus group: the Cerebrovascular Reserve of stenotic side in diabetes mellitus group is significant lower(P<0.05).Conclusion1. The Cerebrovascular Reserve of stenotic side in patients with severe Carotid stenosis decrease, Carotid artery stenosis is related to cerebrovascular reserve impairment.2. Carotid angioplasty and stenting results in an improvement of cerebrovascular reserve (30 days after CAS).3. The CVR in patients with severe Carotid stenosis and Diabetes decrease more significantly, the improvement of CVR in 30 days after CAS is less than non-Diabetes patients。4. Cerebrovascular reserve impairment is a possible indication of the CAS.5. Cerebrovascular reserve is a therapeutic effect index of the CAS...