A Study about the changs of cerebral hemodynamics in carotid endarterectomy

Abstract

Objective To study how to prevent cerebral ischemia and hyperperfusion syndrome during carotid endarterectomy (CEA).Methods Twenty-ninth cases of patients undergoing CEA (35 procedures in total) with carotid artery stenosis were divided into bilateral (group A) and unilateral (group B) stenosis groups.During CEA,the regulation of blood pressure was according to the changes of the ipsilateral middle cerebral artery mean flow velocity (MCA Vm) detected by transcranial Doppler (TCD):if the MCA Vm after carotid artery occlusion was lower than 70％ of that before occlusion,the blood pressure should be increased; and if the MCA Vm after release cross was higher than 100％ of that before carotid artery occlusion,the blood pressure should be decreased.All cases in the study were underwent transcranial Doppler,color Doppler flow imaging,CT angiography,CT perfusion imaging,Magnetic resonance imaging,and/or digital subtraction angiography before and after surgery.Results (1) In the two groups:the MCA Vm of the intraoperation side before carotid artery occlusion was decreased as compared with that before anesthesia (P =0.000).After carotid artery occlusion,the MCA Vm was decreased slightly as compared with that before occlusion (P ＞ 0.05),and the blood pressure was increased (23.76 ±9.15)％ (P =0.000) ; The MCA Vm after release cross was higher than that before occlusion(P =0.000),the blood pressure was decreased (6.70 ±6.89)％ (P =0.000).(2) Between the two groups:After carotid artery occlusion,the MCA Vm of the intraoperation side in group B was decreased than that in group A (P ＜ 0.05).The enhance rate of the blood pressure was higher than that in group A(P ＜0.01).After release cross,the reduce rate of the blood pressure in group B was lower than that group A (P ＜ 0.05).The MCA Vm between the two groups had no statistic difference (P ＞ 0.05).(3) After surgery,the cerebral perfusion of all patients of the intraoperation side was improved versus that before surgery.Conclusion During CEA,TCD could real-time monitor the changes of cerebral hemodynamics,evaluate the cerebral perfusion,guide the to regulate the blood pressure timely,so as to improve the success rate of surgery significantly. Key words: Ultrasonography, Doppler, transcranial ; Carotid stenosis ; Carotid endarterectomy; Cerebral hemodynamics