[Evaluation of cerebral hemodynamics by transcranial Doppler ultrasonography in carotid endarterectomy].

The authors studied the linear blood flow rate (LBFR) in the middle cerebral artery (MCA) which was measured by means of transcranial dopplerography during carotid endarterectomy in 25 patients. Analysis of the results showed that the changes of LBFR in the MCA correlate with alterations in blood pressure: LBFR in the MCA reduced most during compression of the common carotid artery in patients with considerable affection of the contralateral carotid artery. The maximal increase of the blood flow during compression of the common carotid artery occurred when the initial LBFR in the MCA was lowest. After the blood flow in the common carotid artery is restored the LBFR in the MCA is determined by the degree of stenosis of the artery which is operated on and the degree of collateral circulation. The method makes it possible to determine in time the need for additional measures of protection of the brain from ischemia.