Blunt cerebrovascular injury
Blunt cerebrovascular injury (BCVI), sometimes called blunt cervicovascular injury or blunt carotid and vertebral artery injury, refers to a spectrum of injuries to the cervical carotid and vertebral arteries due to blunt trauma.
Epidemiology
It is often part of multi-trauma with a significant series of blunt trauma CTA reporting an incidence of approximately 1% . A large systematic review and meta-analysis of more than 120,000 trauma patients reported an incidence ranging from 0.18 to 2.7% .
Pathology
Primarily, the injury is caused by longitudinal stretching and injury to the vessels. Acceleration-deceleration can cause rotation and hyperextension of the neck, stressing the craniocervical vessels, which is the mechanism for the most common cause of BCVI: motor vehicle accidents (MVA). A direct blow to the neck or base of the skull may cause injury to the carotid or vertebral arteries.
BCVI can affect multiple vessels (18-38%) and occurs in typical locations :
- internal carotid artery (ICA)
- cervical ICA just below the skull base
- petrous ICA
- cavernous ICA
- vertebral artery
- cervical vertebral artery as it passes through the transverse foramina
Screening
Several screening tools have been developed to identify those at risk of BCVI and limit the use of angiography:
In general, BCVI is at higher risk if there is a high energy transfer mechanism along with clinical or imaging evidence of significant craniofacial, cervical, or upper thoracic injuries. About 70% are associated with cervical spine fractures .
Classification
The Biffl scale describes the vascular injury on angiography (either CTA or DSA) on a scale of I to V, with higher grades of carotid injury associated with a high risk of stroke.
Radiographic features
CT
Signs on CT angiography of vascular injury include
- minimal intimal injury (irregularity)
- intimal flap
- dissection with or without intramural hematoma
- pseudoaneurysm
- transection
- vessel occlusion
- AV fistula
Angiography (DSA)
The signs of BCVI on DSA are the same as CTA. A 2011 study of screening 32-channel multidetector CT compared to DSA showed that DSA is far more sensitive than CTA .
Treatment and prognosis
When undiagnosed, there is high morbidity and mortality, primarily from cerebral infarction. The risk for stroke with carotid injury depends on the grade of injury (see separate article on Biffl grade). The risk of cerebral infarction following BCVI is reduced with antithrombotic therapy, but this can be a difficult management decision as often there is also concomitant intracranial hemorrhage from the primary trauma. In select cases, stenting of the injured vessel or open surgical repair is performed.
Differential diagnosis
- technical and patient artefact
- normal vascular variants
- atherosclerotic plaque
