You receive a BAT call about a 31 year-old male who has come off his bicycle after running into a stationary car at ~30 km/hour. Bystanders report that he was thrown 3-5m and had a loss of consciousness of ~3 minutes without witnessed seizure activity.
On arrival, he is alert but confused (GCS E4 V4 M6). He is haemodynamically normal with the only injuries noted on primary survey being a significant left forehead haematoma and midline cervical tenderness at C5-7. His upper and lower limb neurological assessment, as well as his cranial nerve exam is normal.
You order him a CT brain and cervical spine as part of his trauma assessment…
The CT brain shows significant left frontal contusions.
CT C-spine shows a fracture of C6 involving the left facet joint with extension into the transverse foramen.
Here are the more detailed CT’s…
Vertebral Artery Injury.
- Occurs in ~0.1% of trauma patients (includes carotid & vertebral vessel injury).
- ~1% of asymptomatic patients of blunt trauma & up to 2.7% of patients w/ Injury Severity Score ≥16.
- >70% of vertebral artery injuries are associated w/ cervical spine fractures.
- Majority are diagnosed after the development of secondary CNS ischaemia.
- May follow mild events such as sudden rotation or hyperextension of neck.
- Can occur from yoga, coughing or vomiting.
- Seen more frequently in people with underlying pathology of vessel wall (eg. connective tissue disorders).
- The vertebral arteries are susceptible to mechanical injury due to relationship to neighbouring bony structures & ligaments.
- Most susceptible to injury at the entrance into the transverse foramen (C6) & at C1-2.
- Occurs due to shearing forces at junctions between fixed & mobile segments.
- Intimal disruption may lead to complete thrombotic occlusion, subintimal haematoma, dissection and pseudoaneurysm formation.
- Diagnosis is often delayed as 17-35% of patients do not develop neurological signs for > 24 hours after injury.
- Concomitant intoxication & head-injury can further delay diagnosis.
- Mortality 8-18%.
Patients of significant blunt head trauma with;
- GCS ≤ 8
- Basilar skull fracture
- Diffuse axonal injury
- Le Fort II or III facial fractures
- Facial haemorrhage
- Expanding neck haematoma
- Attempted hanging with anoxic brain injury
- Focal neurological signs that cannot be explained by the CT-brain.
- Extension into foramen transversarium
- Subluxation or rotational component
- Catheter-based angiography (DSA)
- Remains ‘gold standard’.
- Risks include embolism, bleeding & reaction to contrast.
- Multislice (8 or greater) just as good as formal angio.
- Sn 97.7%, Sp 100% – compared to catheter angiography.
- Accurately diagnoses dissection, without risks associated with conventional angiography.
- Provides other information also [eg. cerebral ischaemia, cord contusion, spinal ligamentous injury, size of thrombus].
- Not adequate for screening. Poor sensitivity.
Given the mechanism of injury and the fracture through the transverse foramen, you order him a carotid and vertebral CT angiogram…
… which demonstrates interruption of flow in the left vertebral artery consistent with dissection.
Generally based on the following Biffl et al Grading System…
- Grade I & II injuries should be treated w/ antithrombotic agents such as heparin or aspirin.
- Heparin & antiplatelet therapy can be used with equivalent results.
- Heparin started w/out a bolus.
- Warfarin therapy should follow w/ target INR of 2-3 (for 3-6 months).
- Grade III injuries rarely resolve with observation or heparinisation.
- Invasive therapy should be considered.
- Repeat imaging (CT-A) should be performed for grades I-III injuries at 7-10 days post-injury.
- Tintinalli’s Emergency Medicine: A Comprehensive Study Guide. 7th Edition.
- Rosenʼs Emergency Medicine. Concepts and Clinical Approach. 7th Edition
- Bromberg WJ et al. Blunt cerebrovascular injury practice management guidelines: The eastern association for the surgery of trauma. J Trauma. 2010; 68; 471-477
- Cothren CC et al. Cervical spine fracture patterns predictive of blunt vertebral artery injury. J Trauma. 2003 Nov;55(5):811-3.
- Mueller CA et al. Vertebral artery injuries following cervical spine trauma: a prospective observational study. Eur Spine J. 2011 Dec;20(12):2202-9.
- Desouza RM et al. Blunt traumatic vertebral artery injury: a clinical review. Eur Spine J. 2011 Sep;20(9):1405-16.
- Biffl WL, Moore EE, Offner PJ, Brega KE, Franciose RJ, Burch JM. Blunt carotid arterial injuries: implications of a new grading scale. J Trauma. 1999;47:845– 853.