Blunt cerebrovascular injury
Blunt cerebrovascular injury (BCVI) is an uncommon but serious consequence of blunt trauma to the head and neck.
It is often part of multi-trauma with a significant series of blunt trauma CTA reporting an incidence of approximately 1% 3. A large systematic review and meta-analysis of more than 120,000 trauma patients reported an incidence ranging from 0.18 to 2.7% 7.
Primarily, the injury is caused by longitudinal stretching 1 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 injury the carotid or vertebral arteries.
BCVI can affect multiple vessels (18-38%) and occurs in typical locations 1:
internal carotid artery (ICA)
- cervical ICA just below the skull base
- petrous ICA
- cavernous ICA
- cervical vertebral artery as it passes through the transverse foramina
Several screening tools have been developed to identify those at risk of BCVI and limit the use of digital subtraction angiography (DSA):
In general, BCVI is at higher risk if the following are present 1:
- severe facial injuries
- severe cervical spine injuries
- fractures involving the transverse foramen
- fractures of C1 to C3
- cervical spinal subluxation
- base of skull fractures, especially those involving the carotid canal
- diffuse axonal injuries
- near hanging
- major thoracic trauma
The Biffl scale 2 describes the vascular injury on angiography (either CTA or DSA) and has prognostic and therapeutic implications, with higher grades associated with a high risk of cerebral infarction:
- grade I: mild intimal injury or irregular intima
- grade II: dissection with raised intimal flap / intramural haematoma with luminal narrowing >25% / intraluminal thrombosis
- grade III: pseudoaneurysm
- grade IV: vessel occlusion/thrombosis
- grade V: vessel transection
This scale is also known as the Denver scale, which is not to be confused with the Denver criteria, a set of clinical and risk factors that promote CTA screening for BCVI.
- 70% are associated with cervical spine fractures 8
Signs on CT angiography of vascular injury include 1
- minimal intimal injury (irregularity)
- intimal flap
- dissection with or without intramural haematoma
- vessel occlusion
- AV fistula
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 4.
Treatment and prognosis
When undiagnosed, there is high morbidity and mortality, primarily from cerebral infarction. The risk of cerebral or posterior fossa infarction following BCVI is reduced with anticoagulation, but this can be a difficult management decision as often there is also concomitant intracranial haemorrhage from the primary trauma. In select cases, stenting of the injured vessel is performed.
- technical and patient artefact
- normal vascular variants
- atherosclerotic plaque
- 1. Sliker CW. Blunt cerebrovascular injuries: imaging with multidetector CT angiography. Radiographics. 2008;28 (6): 1689-708. doi:10.1148/rg.286085521 - Pubmed citation
- 2. Biffl WL, Moore EE, Offner PJ et-al. Blunt carotid arterial injuries: implications of a new grading scale. J Trauma. 1999;47 (5): 845-53. J Trauma (link) - Pubmed citation
- 3. Schneidereit NP, Simons R, Nicolaou S et-al. Utility of screening for blunt vascular neck injuries with computed tomographic angiography. J Trauma. 2006;60 (1): 209-15. doi:10.1097/01.ta.0000195651.60080.2c - Pubmed citation
- 4. DiCocco JM, Emmett KP, Fabian TC et-al. Blunt cerebrovascular injury screening with 32-channel multidetector computed tomography: more slices still don't cut it. Ann. Surg. 2011;253 (3): 444-50. doi:10.1097/SLA.0b013e31820d946b - Pubmed citation
- 5. Ciapetti M, Circelli A, Zagli G et-al. Diagnosis of carotid arterial injury in major trauma using a modification of Memphis criteria. Scand J Trauma Resusc Emerg Med. 2010;18 (1): 61. doi:10.1186/1757-7241-18-61 - Free text at pubmed - Pubmed citation
- 6. Cothren CC, Moore EE. Blunt cerebrovascular injuries. Clinics (Sao Paulo). 2006;60 (6): 489-96. Pubmed citation
- 7. Franz RW, Willette PA, Wood MJ et-al. A systematic review and meta-analysis of diagnostic screening criteria for blunt cerebrovascular injuries. J. Am. Coll. Surg. 2012;214 (3): 313-27. doi:10.1016/j.jamcollsurg.2011.11.012 - Pubmed citation
- 8. Fassett DR, Dailey AT, Vaccaro AR. Vertebral artery injuries associated with cervical spine injuries: a review of the literature. J Spinal Disord Tech. 2008;21 (4): 252-8. doi:10.1097/BSD.0b013e3180cab162 - Pubmed citation