[Possibilities of instrumental methods of diagnosis of unstable atherosclerotic plaques of carotid arteries].

Today there exists a wide variety of laboratory and instrumental methods aimed at diagnosing an unstable carotid aortosclerotic plaque. Assessment of the laboratory indices is not sufficiently effective since it does not allow of revealing the fact of the formation of an unstable plague at early stages and to determine its localization. The instrumental methods employed (ultrasonographic study, magnetic resonance imaging, multiplanar computed tomography, positron emission tomography) were focussed on detecting pathomorphological markers of instability - thickness of the fibrous coating, structural plaques, the presence of erosions, ulcerations, haemorrhages, calcifications, lipid nucleus, activity of the cellular processes inside the plaque. The revealed signs promote early diagnosis of unstable atherosclerotic plaque with the determination of its localization. Nevertheless, they do not provide evidence about the danger of its rupture, whereas the overwhelming majority of acute vascular catastrophes including acute impairments of cerebral circulation is directly associated with arterial thrombosis resulting from rupture of the atherosclerotic plaque. Therefore, search for new methods aimed at prediction of complications of the atherosclerotic plaque which would be employed in routine clinical practice still remain urgently important today. The most promising is the study of the state of the atherosclerotic plaques of carotid arteries for prediction of acute impairment of cerebral circulation.

[Comparison of morphological features of carotid arteries atherosclerotic plaques with clinical-instrumental data in symptomatic and asymptomatic patients with severe carotid atherosclerosis].

A complex histomorphometric and clinical-instrumental analysis of atherosclerotic lesions of the carotid arteries obtained during carotid endarterectomies (CEE) of patients with hemodynamically significant stenoses was conducted. Two groups of patients were compared: symptomatic, which earlier underwent cerebral vascular accident (CVA) or transitory ischemic attacks (TIA), and asymptomatic ones with no complications of the disease. Statistical analysis of clinical and laboratory data showed no significant differences between two groups except for the level of lipoprotein(a) [Lp(a)] in the blood plasma, which was higher (p<0.05) in asymptomatic patients compared with symptomatic ones. Statistical analysis of carotid arteries ultrasound duplex scanning (USDS) in the preoperative period did not reveal significant differences in the degree of maximum vessels stenosis between the compared groups of patients. Surface defects of atherosclerotic plaques (ASP) were shown to be significantly more common (p<0.05) in the group of symptomatic patients compared with asymptomatic ones. According to histological analysis 88% of extracted ASP was unstable in symptomatic patients and 77% of ASP - in asymptomatic patients. This may indicate high risk of CVA/TIA in both groups of patients. Statistical evaluation of magnetic resonance tomography (MRT) and USDS techniques in comparison with abilities of the most reliable histological analysis showed that both non-invasive diagnostic methods are highly sensitive in detecting unstable ASP, though MRT showed higher level of specificity compared with USDS.