The utility of using the bispectral index-Vista for detecting cross-clamping decline in cerebral blood flow velocity.

Background: Patients undergoing carotid endarterectomy for extracranial internal carotid artery stenosis are at risk of cerebral ischemia/hypoperfusion. Criterion recommended by European and American committees to determine whether to place a shunt consisted of a decline in transcranial Doppler ultrasonography-measured middle cerebral artery blood flow velocity (MCBFV) to < 30% to 40% of intraoperative preclamp value.

Objective: To assess the discriminative power of the bispectral index (BIS)-Vista monitor for detecting a 40% decline in MCBFV with cross-clamping.

Color Doppler imaging evaluation of proximal vertebral artery stenosis.

Objective: The sonographic diagnostic criteria for vertebral artery stenosis have not been fully investigated. The purpose of this study was to assess hemodynamic parameters at color Doppler imaging and to determine, with digital subtraction angiography as the reference standard, the optimal thresholds for evaluation of proximal vertebral artery stenosis.

Materials And Methods: Among 653 patients with symptoms of ischemia of the posterior circulation, 247 subjects with normal arteries or stenosis of the proximal vertebral artery confirmed with digital subtraction angiography were included in the study.