[Ultrasonographic control of cerebral blood flow in patients with stenosis of brachiocephalic arteries before and after carotid endarterectomy].

The authors studied the parameters of arterial and venous blood flow in patients presenting with haemodynamically significant atherosclerosis of the carotid arteries before and after carotid endarterectomy, as well as while carrying out functional tests. Comparing the indices of arterial blood flow in the Study Group consisting of 52 patients and the Control Group comprising 15 apparently healthy volunteers at rest prior to the operation revealed statistically significant differences of volumetric parameters of blood flow in the internal carotid artery. The obtained results showed that the breath-holding test was accompanied and followed by increased velocity of blood flow in the middle cerebral artery (MCA) on the side contralateral to stenosis, with the reactivity index (RI) amounting to 0.98±0.20, which statistically significantly differed from the RI in the Control Group patients (1.28±0.13). The forced respiration test demonstrated a decrease in the volumetric indices of blood flow in the MCA on the side of stenosis, as well as an increase of the maximum end-diastolic velocity of blood flow on the side contralateral to stenosis. The test with sublingual administration of nitroglycerin appeared to result in reduced blood flow in the MCA. The supratrochlear test demonstrated decreased velocity of blood flow in the supratrochlear artery. Studying the venous link of cerebral vessels after the operation showed that statistically significant differences were revealed only on the side contralateral to stenosis as compared with the values prior to revascularization. An increase of blood flow in the internal jugular veins after the operation on the side contralateral to the operation was apparently suggestive of an adequate distribution of blood flow through the main vessels of the brain.