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

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/s(2)) of CVR was calculated as ratio of DV 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/s(2) and after the operation was 0.07 +/- 0.03 cm/s(2) ( 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.