Patterns of Fibrin Deposits in Carotid Artery Plaques

Abstract
We evaluated 40 consecutive carotid endarterectomy specimens for the presence of fibrin. Intraplaque hemorrhage was noted in 93% of specimens. At the plaque surface, there were two patterns of fibrin distribution. Type I, suggesting a lumen thrombus, was found in 7 specimens. Type II, suggesting an intraplaque hemorrhage at the lumen surface, was found in 15 specimens. These changes were not significantly associated with the presence of ischemic symptoms or the use of antiplatelet or anticoagulant medications. All specimens with Type I change had arteriographic evidence of at least 70% diameter stenosis. The frequent lack of fibrin at the plaque surface suggests that there may be inherent limitations of standard medical treatment for carotid artery disease.