Combined use of aspirin and heparin inhibits in vivo acute carotid thrombosis.
OBJECTIVE
Carotid atherosclerotic thrombosis is an important cause of ischemic stroke in Western countries. The therapeutic efficacy of either aspirin or heparin alone in this setting is still controversial. Recently we developed a simple model, the "clamp" method, to induce acute carotid mural thrombosis in vivo in guinea pigs. In this study, we used this model to evaluate the antithrombotic effects of aspirin, heparin, and their combination.


METHODS
Sixty-four male guinea pigs were divided equally into control, aspirin, heparin, and combined groups. Physiological saline, aspirin (5 mg/kg body wt), heparin (200 units/kg body wt), or a combination of aspirin and heparin, respectively, was injected via the jugular vein before the use of the clamp method. Thirty minutes after the injection of saline or drug(s), Péan's forceps was used to clamp the carotid artery at a tangent angle for 3 minutes. One hour later, the carotid artery was resected and prepared for observation under a scanning electron microscope or light microscope to evaluate the degree of mural thrombosis.


RESULTS
The results showed that the combination of aspirin and heparin had an excellent effect in inhibiting in vivo acute carotid thrombosis (p < 0.001) and was significantly better than the effect of aspirin alone (p < 0.01) or heparin alone (p < 0.01).


CONCLUSIONS
Our study clearly demonstrated that the combined use of aspirin and heparin produced a much better antithrombotic effect than either agent alone at sites of carotid endothelial injury when given before the injury. This combined regimen may be useful clinically in acute carotid thrombosis secondary to carotid diseases or carotid endarterectomy.
Department of Internal Medicine, College of Medicine, National Taiwan University, Taipei, Republic of China.
Z S
ZS
Huang
C M
CM
Teng
T K
TK
Lee
C T
CT
Shun
C Y
CY
Wang
D000818:Animals; D001241:Aspirin / Q000494:pharmacology*; D002339:Carotid Arteries / Q000648:ultrastructure; D002341:Carotid Artery Thrombosis / Q000473:pathology / Q000517:prevention & control*; D004195:Disease Models, Animal; D004338:Drug Combinations; D004353:Drug Evaluation, Preclinical; D006168:Guinea Pigs; D006493:Heparin / Q000494:pharmacology*; D006495:Heparin, Low-Molecular-Weight / Q000627:therapeutic use; D008297:Male; D010974:Platelet Aggregation; D011517:Prothrombin Time
D004338:Drug Combinations; D006495:Heparin, Low-Molecular-Weight; D006493:Heparin; D001241:Aspirin