Pathologic aspects of carotid plaques: surgical and clinical significance

Abstract

From January 1988 to December 1989, we performed a total of 278 carotid thromboendarterectomies. The endarterectomized plaque was systematically confined for anatomopathological analysis by standard light microscopic techniques. The authors looked for clinicopathologic correlation of the histology of the endarterectomy specimen with the clinical data. Twenty eight plaques were not suitable for analysis and classification. The remaining 250 plaques were subdivided in 216 (36%) complicated plaques and 34 (14%) simple fibrous plaques. In the complicated plaques, the pathologist described one or more of the following pathologic characteristics: organized intraplaque hematoma (observed in 115 plaques), fresh thrombus (50), ulceration (92), and recent intraplaque hemorrhage (168). More than one anatomopathologic aspect were observed in most of the complicated plaques. Fifty three percent of these complicated plaques were symptomatic with corresponding neurologic deficit (amaurosis, TIA, RIND or stroke), versus 21% of the simple plaques (p < 0.001). For plaque characteristics the only significant clinicopathologic correlation was found in plaques with fresh thrombus which were symptomatic in 70% of cases, and ulcerated plaques (symptomatic in 66% of cases). This comparative study yielded no significant evidence of increased predisposition to neurologic deficit for the other morphological aspects (intraplaque hemorrhage, healed ulceration, organized hematoma). The histology of the endarterectomy specimen was compared with the preoperative echopattern of 154 plaques. Thirty four ultrasound images were of poor quality. The 120 adequate echographies revealed 22 dense hyperechogenic homogenous plaques, 28 soft hypoechogenic homogenous plaques, 53 inhomogenous plaques, and 13 mixed plaques. According to the surface, lesions were subdivided as smooth (N. = 63) or irregular (N. = 57). Echography recognized fibrous plaques (dense homogenous hyperechogenous lesions), with a specificity of 87% and a sensitivity of 56%. Recent intraplaque hemorrhage is echographically apparent as a hypoechogenic area in 88% of cases, what corresponds to a specificity of 79% and a sensitivity of 75%. Echography proved to be more accurate than angiography in determining the presence or absence of ulceration. The study evidenced that plaque morphology rather than luminal narrowing plays a primary role in cerebral ischemic disease. The ability to characterize the pathology of carotid atheroma by duplex scan makes the clinicopathologic correlation of carotid plaques of practical importance.