Clinical Evaluation Of Atherosclerotic Plaque Vulnerability With Carotid Doppler Ultrasonography

Atherosclerosis is important pathological and clinical basis of the stroke occurrence and development, carotid stenosis is a vicious long-term outcome of severe atherosclerosis, about a quarter of the ischemic stroke is associated with carotid artery stenosis, especially closely related to the vulnerable plaques. According to this, our prospective topic aimed to study the feasibility of the carotid Doppler ultrasonography assessment of plaque vulnerability, analysis correlation between plaque vulnerability and ischemic stroke.Part I:Evaluation of the feasibility of carotid atherosclerotic plaque vulnerability with carotid Doppler ultrasonographyObjective Prospectively investigate the feasibility of carotid Doppler ultrasonography(CDU) in evaluating the vulnerability of carotid atherosclerosis plaques.Methods 33 patients(36 plaques) performed carotid endarterectomy were scheduled for CDU and HRMRI examinations pre-operation to evaluate the vulnerability of carotid atherosclerosis plaques. Then the general appearance and internal composition were observed post-operation according to the Pathological standards, remove the plaque along the abscissa direction for different levels of Pathological specimens. Compare the corresponding level of CDU with that of HRMRI and Pathological results respectively in reference to the bulb to estimate the vulnerability of the plaque. Calculate the sensitivity, specificity, positive predictive value, negative predictive value of the CDU and HRMRI in evaluating the vulnerability of the plaque. The standard of CDU setting vulnerable plaques: hypoechoic plaques inside the plaques with or without irregular shape, fibrous cap rupture, blood flow filling(ulcer plaques), intraplaque hemorrhage. The standard of CDU setting stable plaques: homogeneous plaques characterized by medium echo with smooth surface and integrated fibrous cap or homogeneous strong plaques.Results 1. CDU assess vulnerable plaques accounted for 80.6%(29/36), stable plaques accounted for 19.4%(7/36); HRMRI assess vulnerable plaques accounted for 83.3%(30/36), stable plaques accounted for 16.7%(6/36); Pathology assess vulnerable plaques accounted for 77.8%(28/36), stable plaques accounted for 22.2%(8/36). 2. The sensitivity and specificity of CDU evaluating vulnerable plaques were respectively 93.3% and 83.3%,positive predictive value and negative predictive value were respectively 96.6% and 71.4%. The sensitivity and specificity of HRMRI evaluating vulnerable plaques were respectively 90% and 83.3%, and positive predictive value and negative predictive value were respectively 96.4% and 62.5%. 3. The results of CDU were well accordant to that of Pathology results(Kappa=0.916,P<0.01). The results of CDU were well accordant to that of high resolution magnetic resonance(HRMRI) results(Kappa=0.832,P <0.01).Conclusion CDU can real-time identify the vulnerable plaques accurately and provide a reliable basis for individual clinical treatment.Part II:Correlation Study Between carotid artery plaque vulnerability and ischemic strokeObjective Correlation study between carotid artery plaque vulnerability and ischemic stroke.Methods 43 patients(48 plaques) performed carotid endarterectomy were scheduled for carotid Doppler ultrasonography(CDU) pre-operation. The standard of vulnerable plaques: hypoechoic plaques inside the plaques with or without irregular shape, fibrous cap rupture, blood flow filling(ulcer plaques), intraplaque hemorrhage. The standard of stable plaques: homogeneous plaques characterized by medium echo with smooth surface and integrated fibrous cap or homogeneous strong plaques. Patients were classified into ischemic stroke group(ischemic group) and non ischemic stroke group(non ischemic group) according to whether ischemic stroke symptoms occurred during the last 6 months in reference to the fourth national conference on cerebrovascular disease; then further analysis the correlation of the ultrasonic characteristics of vulnerable plaques between ischemic stroke.Results CDU assess vulnerable plaques in ischemia group account for 78.1%(25/32), stable plaques accounted for 21.9%(7/32); vulnerable plaques in non ischemia group account for 31.2%(5/16), stable plaques account for 68.8%(11/16) vulnerable plaques in ischemia group were obviously much more than that of non ischemia group(P<0.01).Conclusion The vulnerability of plaques were closely related to that of ischemic stroke. The accurate assessment of vulnerability of plaques can provide reliable basis for analyses the pathogenesis of the ischemic stroke and prevent it happens.