Study halted prematurely prior to enrollment of first participant.

Originally thought to be a rare occurrence, BCVI are now diagnosed in approximately 1% of blunt trauma patients. Initially BCVI were thought to have unavoidable devastating neurologic outcomes. But early reports suggested anticoagulation might decrease these events. If untreated, carotid artery injuries (CAI) have a stoke rate up to 50% depending on injury grade, with increasing stroke rates correlating with increasing grades of injury. Current studies report early treatment with antithrombotics - either heparin or anti-platelet agents - in patients with BCVI markedly reduces stroke rates and resultant neurologic morbidity. As reports of bleeding complications have altered heparin protocols in these patients, the use of antiplatelet agents is attractive. Although heparin has been has been proposed as the gold standard treatment due to its initial empiric use, no comparative studies of antithrombotic agents has been performed.

In sum, Grade I-III blunt carotid and vertebral arterial injuries (BCVI) have the potential for stroke, and should be treated. Heparin has not been shown to clearly improve healing rates compared with antiplatelet therapy. The purpose of this study is to determine whether systemic anticoagulation alters the course of Grade I-III BCVI compared with antiplatelet therapy. The investigators study hypothesis is that Grade I-III BCVI will heal or progress to pseudoaneurysm formation, independent of systemic antithrombotic regimen, and that the combination of aspirin and clopidogrel is equally efficacious in preventing neurologic symptoms compared to systemic heparin associated with Grade I-III BCVI.

Inclusion Criteria:

• Patients greater than 18 years old with documented grade I-III blunt cerebrovascular injuries.

Exclusion Criteria:

• Pregnancy
• Nasal polyps
• Previous gastrointestinal bleeding secondary to antiplatelet medications
• Contraindication to systemic anticoagulation.