Dynamic cerebral autoregulation in carotid stenosis before and after carotid stenting

BackgroundImpaired dynamic cerebral autoregulation (DCA) has been shown in patients with severe (≥70%) internal carotid artery (ICA) stenosis, but DCA in moderate (50% to 69%) ICA stenosis, especially its response to carotid revascularization, has rarely been reported. Our study aimed to characterize DCA in severe and moderate ICA stenosis before and after carotid stenting.MethodsThis study included 21 patients with ICA stenosis ≥50% who received carotid stenting. Data of arterial blood pressure and cerebral blood flow velocity of the middle cerebral artery, measured by transcranial Doppler, were collected for 10 minutes ≤24 hours before and after stenting. The DCA index, represented as aMx, was assessed by calculating the Pearson product-moment correlation coefficient of spontaneous arterial blood pressure and cerebral blood flow velocity fluctuations. The relationship between aMx and stenotic severity and also alternations of aMx before and after stenting were assessed.ResultsCarotid stenting was effective to improve the DCA in the stenting side but not in the contralateral nonstenting side. In considering individual ICAs, the average aMx (mean ± SD) increased significantly from ICA stenosis