Pathological aspects of carotid plaques. Surgical and clinical significance.

We examined 134 carotid plaques microscopically in 125 consecutive patients, and found 21 (15.7%) had simple fibrous plaques versus 113 (84.3%) complicated plaques. The following plaque characteristics were present: intraplaque hemorrhage (73 plaques), ulceration (83 plaques), fresh thrombus (93 plaques), and recanalized thrombus (22 plaques). An average of 2.4 characteristics were observed in each complicated plaque. The only significant (p less than 0.05) clinico-pathologic correlation was the presence of fresh thrombi, found in 80% of the plaques from patients with a previous transient ischemic attack, in 93% of those with nonfocal neurologic symptoms, and in 80% of those with amaurosis fugax. Analysing the localization of the fresh thrombus (mural or intraluminal), we found that fresh thrombus in symptomatic plaques was most frequently (NS) (71 to 77%) exposed to the vessel lumen. Ulceration without fresh thrombus, plaque hemorrhage and recanalized thrombus were also found in a considerable number of asymptomatic patients, of whom 85% (33/41) presented a form of complicated plaque.