Biomechanics of Carotid Artery Dissection in Vehicular Accidents

Carotid and vertebral artery dissections are often associated with hyperextension of the neck or rapid hyperrotation of the head. In each of these cases, the arteries are damaged by being stretched over the upper cervical vertebra. A dissecting aneurysm ensues in which blood makes its way between the layers of the vessel wall eventually resulting in a thrombosis and cerebral infarct. Typical mechanisms of these injuries in the automotive environment are the absence of a head restraint, shoulder harness trauma, and whiplash. These mechanisms together with blunt trauma and inertial forces are discussed.