the case.
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…
httpv://www.youtube.com/watch?v=vUZtH38sG1o
httpv://www.youtube.com/watch?v=31eRTgX87aw
Good question.
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.
- Mechanism.
- 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.
C-spine fracture:
- C1-C3
- Extension into foramen transversarium
- Subluxation or rotational component
- Catheter-based angiography (DSA)
- Remains ‘gold standard’.
- Risks include embolism, bleeding & reaction to contrast.
- CT-angiography
- Multislice (8 or greater) just as good as formal angio.
- Sn 97.7%, Sp 100% – compared to catheter angiography.
- MRI
- Accurately diagnoses dissection, without risks associated with conventional angiography.
- Provides other information also [eg. cerebral ischaemia, cord contusion, spinal ligamentous injury, size of thrombus].
- Ultrasound
- 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.
Chris,
Great case- general comment here- the thing that I wonder is why we aren’t more aggressive with doing CTA of the neck in trauma patients. If you have decided that the patient is sick enough to need a pan-scan- the best approach I have seen is to split the contrast between the neck and the aorta and do a CTA of the neck routinely. You’ll still get the CT c-spine for the bony injuries but you’ll also get the neck vasculature.
Catching these dissections early can avoid significant morbidity and mortality in young patients who may not even have other injuries, yet the EAST trauma guidelines don’t suggest routine CTA in those getting pan-scanned anyway.
I have a small interest in this as I had a patient in residency that had an undiagnosed carotid dissection from blunt trauma (no other injuries) and went on to have a stroke with significant impairment- yet he didn’t meet any Denver criteria for evaluation of his vasculature. If it had been caught sooner, the literature is pretty clear that even an aspirin could have significantly lowered his risk of subsequent stroke. I am like the Dos Equis guy- “I don’t pan scan all my trauma patients, but when I do, I prefer to CTA the neck” What are your thoughts on this?
As always- great post
Steve
Hi Steve,
Thanks for your great comment ! I think you’ve hit the nail on the head there in that these can be occult injuries (sometimes from quite innocuous mechanisms) which carry devastating consequences if missed.
In my current shop, we are quite aggressive with our CT-imaging but I’d have to say we don’t routinely perform angiography of the neck in asymptomatic patients having a pan-scan. The patients who tend to get these CT-angios are ones that at least have external evidence of neck trauma (eg. contusion from seat-belt, haematoma) OR those with a concerning mechanism of injury (ie. attempted hanging, strangulation etc). Alternatively, we’ll send them back for further scans if they have a concerning C-spine injury (like the patient in this case).
The ones who I will now advocate for CT in, are the trauma patient intubated for neurological reasons who appear to have negative CTB’s…
What about those you pan-scan who are GCS15, neurologically intact with no evidence of external neck trauma ? Do they still get contrast from you ??
Cheers,
Chris.
Chris,
Your question at the end is the 64,000 dollar question. The practice I have seen in the US at level 1 trauma centers is that all pan-scans are done with contrast. Where I did my residency, when I started my training the usual practice was to contrast the aorta only. So this amounted to CT Chest, Abdomen, and Pelvis with IV contrast, with non-contrasted studies of the head and neck. Ironically, just around the time this patient came in we were changing the protocol so if a pan-scan was deemed necessary, the contrast was split between the neck and the aorta. The same amount of contrast was used- just divided differently. (Which begs the further question- why weren’t we using less contrast before when it was aorta only? I digress…).
My opinion is that if you are going to use contrast anyway for the C/A/P, you might as well CTA the neck as long as you can divide the contrast appropriately and not end up giving more than usual. You’ll catch these occult injuries before they cause strokes that can be devastating. This may take a change to your pan scan protocol so it’s probably necessary to get your CT techs and radiologists on board but in my opinion, it’s worth it- even in those GCS 15 patients given how minor the mechanisms can be.
Just my 2 cents although- I am surprised I haven’t seen this line of thinking expressed in the guidelines- maybe in the future.
Cheers,
Steve