Acceleration of cerebrovascular reactivity as a new supplemental TCD index in patients with severe carotid stenosis before and after carotid endarterectomy

Abstract

Background and purpose: Cerebrovascular reactivity (CVR) examined by transcranial Doppler (TCD) is a useful tool for investigation of cerebrovascular reserve capacity of the normal and compromised brain. The aim of this study was to learn the acceleration of CVR as a possible additional index characterizing the process of cerebrovascular reserve recruitment and the application of this index in symptomatic and asymptomatic patients with severe unilateral carotid stenosis.Methods: Twenty-seven patients with severe unilateral internal carotid artery (ICA) stenosis were included in the study. TCD examination with acetazolamide test was used for the measurement of cerebrovascular reactivity before and after CEA. The acceleration (cm/s2) of CVR was calculated as ratio of ΔV before and after acetazolamide injection related to time of the velocity change.Results: The acceleration of CVR in patients with severe unilateral ICA stenosis before CEA was 0.03 ± 0.03 cm/s2 and after the operation was 0.07 ± 0.03 cm/s2 (p=0.001). CVR was 24.2 ± 20.4 and 42.9 ± 26% correspondently (p=0.01). The correlation index between CVR and acceleration was 0.86 and 0.5 before and after the surgery (p=0.009).Conclusions: The CVR acceleration may be used as a supplemental TCD index in evaluation of cerebrovascular reserve capacity.