Histologic characterization of carotid plaques

From January 1988 to December 1989, we performed a total of 278 carotid thromboendarterectomies. The plaque was systematically prepared for anatomicopathological analysis by standard light microscopic techniques. We sought to correlate 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 as 216 (86%) complicated plaques and 34 (14%) simple fibrous plaques. In the complicated plaques, one or more of the following pathologic characteristics were described: organized intraplaque hematoma (observed in 115 plaques), fresh thrombus (50), ulceration (92), and recent intraplaque hemorrhage (168). Fifty-three percent of these complicated plaques were symptomatic with corresponding neurologic deficit (amaurosis, transient ischemic attacks, reversible ischemic neurologic deficit, or stroke), compared with 21% of the simple plaques (p < 0.001). With regard (o plaque characteristics, the only significant clinicopathologic correlation was found for plaques with fresh thrombus, which were symptomatic in 70% of cases, and for ulcerated plaques (symptomatic in 66% of cases). This comparative study provides no significant evidence of increased predisposition to neurologic deficit for the other morphological aspects (intraplaque hemorrhage, healed ulceration, organized hematoma). We conclude that plaque morphology, rather than luminal narrowing, plays a primary role in cerebral ischemic disease.