Abstract TP242: Internal Carotid Artery Angle and the Risk of Floating Mural Thrombosis in Acute Cerebral Infarction Patients

Abstract

Background and Purpose: Floating mural thrombosis in an internal carotid artery (ICA) is a rare and uncommon pathology with a high risk of embolism. Carotid anatomy and geometry may play a role in the pathogenesis of internal carotid artery stenosis. However, their effects to the formation of thrombus are unknown. Therefore, we sought to find whether the ICA angle affected the formation of thrombus or not. Method: We retrospectively analyzed 603 consecutive patients with a diagnosis of acute cerebral stroke from April 2015 to June 2017. We conducted brain MRI/MRA scans and carotid ultrasonography to assess the atherosclerotic change and the prevalence of mural thrombosis. We found four patients (0.6%) with a mobile mural thrombus in the ICA without a significant stenosis. As a control group, we also chose 24 patients who had atherothrombotic infarctions with 50% or less ICA stenosis. We measured the ICA angle which is the angle of deviation of the ICA from a vertical line drawn through the center of the common carotid artery. We investigated the degree of ICA angle as well as traditional vascular risk factors and coagulation factors. Results: The mural thrombosis group was younger than the control group (60.5±14.7 vs. 76.5±8.7 years, p<0.01). The ICA angle was significantly wider in patients with floating mural thrombosis (56.0°:IQR 33.3 to 69.6° vs. 24.5°:IQR 19.9 to 34.6°, p=0.009). There were no significant differences in coagulation factors, vascular risk factors, and comorbidities between the mural thrombosis group and the control group. Conclusion: Our study implies that wide ICA angle is an important factor for the formation of the floating mural thrombosis as well as developing carotid artery atherosclerosis.