Effect of endarterectomy on arterial fibrinolytic activator activity

Although endarterectomy leaves a raw subintimal surface, thrombotic complications are rare. This may be the result of activation of the fibrinolytic system. Fibrinolytic activator activity (FAA) was studied after intimectomy of 3-cm segments of carotid artery in dogs. Endarterectomized segments and contralateral control arteries were resected immediately following intimectomy (group 1) and after blood flow restoration of ten minutes, three hours, and 24 hours (groups 2, 3, and 4, respectively). Areas of fibrinolysis around punch biopsy specimens from each endarterectomy segment and from the control artery were measured. Fibrinolytic activator activity, the ratio of the areas in endartectomized segments to control arteries, was reduced in groups 1 through 3 (mean, 60.7%, 70.1%, and 79.7%, respectively) and was normal in group 4 (94.3%). We conclude that canine FAA is significantly depressed at the endarterectomy site initially but returns to normal at 24 hours. The source of FAA may be synthesis by subintimal structures or delivery by the circulation. During this period of increased thrombogenicity, use of antiplatelet or anticoagulant therapy would be justified.