The Relationship of Carotid Artery Plaque and Stenosis with Microemboli

Abstract

Objective: Microembolic signals (MES) are markers that can be detected by Transcranial Doppler Ultrasonography (TCD) and are risk factors for stroke. The aim of our study is to explore the relationship between the number of MES and the extent of carotid stenosis as well as plaque morphology. Our goal is to provide a fresh perspective on the treatment of carotid stenosis. Materials and Methods: A total of 95 patients, who were admitted to the emergency department of Sultan 2.Abdülhamid Han Training and Research Hospital and were hospitalized with a diagnosis of stroke, were enrolled in the study. Patients with high-risk cardiac diseases were excluded from the study. Detailed medical histories, risk factors, and current medical treatments of the patients were documented, and microemboli detection was conducted using Transcranial Doppler (TCD). The number of microemboli in TCD was obtained by averaging the results of 2 consecutive half-hour follow-ups in a region. Carotid stenosis rates of the patients were determined by computed tomography angiography (CTA) according to the North American Symptomatic Endarterectomy Trial (NASCET) classification, and the plaque morphology was determined according to the Gray-Weale scale of carotid ultrasonography. Patients were categorized into symptomatic and asymptomatic carotid stenosis groups, and the number of microembolic signals (MES) was compared between these groups. Result: MES numbers of 95 patients with symptomatic carotid stenosis; while MES was not detected in 47.4% (n=45); 35.8% (n=34) had 1-2 MES, 8.4% (n=8) had 3-4 MES and 8.4% (n=8) 5 or more MES were detected. The relationship between the MES obtained and carotid stenosis was statistically significant (p<0.001). According to the type of plaque; while there is no MES in 68.2% (n=15) of Type-4 symptomatic stenosis, this rate is only 15% (n=3) in Type-1 stenosis. In addition, 20% (n=4) of Type-1 symptomatic stenosis had MES between 3-4 and 30% (n=6) of 5 or more MES. According to these results, the relationship between plaque type and the presence of MES is statistically significant. (p<0.001) Similar results were obtained in asymptomatic carotid stenosis. Conclusion: TCD is an easy-to-apply, non-invasive imaging technique, and MES detectable by TCD are risk factors for stroke. The relationship between MES and carotid stenosis rate and plaque type heterogeneity is statistically significant.