Value of cerebral vasoreactivity testing in patients with carotid artery disease before and after carotid endarterectomy

In order to evaluate the outcome of endarterectomy, we estimated cerebral vasoreactive capacity (CVC) in 45 patients with carotid artery disease: A. 10 with occlusion, B. 15 with high-grade, and C. 20 with low-grade carotid stenosis. The main hypothesis of our study was that CVC is not equally preserved among patients with the similar carotid pathology. We found a good correlation between impaired CVC on the affected carotid side and the severity of carotid stenosis. After acetazolamine (AZT) stimulation, a significant difference in the AZT response curves was observed between patients with low and patients with high carotid stenosis. The differences were primarily observed in regard of maximum increase in mean blood flow velocities (MBFV), curve slopes, and the time necessary for reaching the plateau. The clinical implication of our study is that CVC assessment may help selecting patients for carotid endarterectomy and making a prognosis. Our results have shown that carotid stenosis impairs cerebral haemodynamics more often than expected. Reduced CVC may be an early indication of reduced collateral potential with a subsequent increased risk of ischaemic stroke.