Referral for Occluded Left Vertebral Artery
Refer immediately to a vascular neurologist or stroke team for any patient with an occluded left vertebral artery, as they will coordinate all diagnostic imaging, medical management, and decisions regarding potential revascularization. 1
Acute Presentation Pathway
If the patient presents with acute posterior circulation symptoms (dizziness, vertigo, diplopia, ataxia, bilateral sensory deficits, altered consciousness), this requires emergency neurologist or stroke team consultation within minutes, not hours. 1 These symptoms can rapidly progress to fatal brainstem or cerebellar infarction, particularly when the left vertebral artery is dominant or when bilateral vertebral disease exists. 2, 3
- For acute stroke within 12 hours: The stroke team will determine eligibility for mechanical thrombectomy if NIHSS ≥6 and PC-ASPECTS ≥6. 4
- Between 12-24 hours from symptom onset: Thrombectomy remains reasonable with the same criteria. 4
Chronic/Stable Disease Pathway
For asymptomatic or stable vertebral artery occlusion discovered incidentally, refer to a vascular neurologist who will serve as the primary coordinator. 1 This specialist will:
- Direct vascular imaging with CTA or MRA (94% sensitivity, 95% specificity) rather than ultrasound alone (only 70% sensitivity). 1, 4
- Prescribe antiplatelet therapy (aspirin 75-325 mg daily or clopidogrel 75 mg if aspirin contraindicated). 4
- Implement aggressive risk factor modification including blood pressure control, statin therapy, diabetes management, and smoking cessation. 4
- Arrange serial surveillance imaging to monitor disease progression. 1
When to Involve Interventional Neuroradiology
The vascular neurologist will consult interventional neuroradiology only after medical therapy fails—specifically, when the patient develops recurrent posterior circulation ischemic symptoms despite optimal antiplatelet therapy and risk factor control. 4 This is critical because endovascular intervention carries a 5.5% risk of periprocedural neurological complications and 0.3% procedural mortality, with 26% restenosis rates at one year. 4
- Catheter-based angiography is required before any revascularization attempt, as neither MRA nor CTA reliably delineates vertebral artery origins. 4
- Revascularization lacks randomized trial evidence showing superiority over medical management. 4
High-Risk Scenarios Requiring Urgent Screening
Certain patients require proactive vertebral artery evaluation even without symptoms:
- Patients with asymptomatic bilateral carotid artery occlusions. 1
- Patients with unilateral carotid occlusion combined with incomplete circle of Willis. 1
These patients depend heavily on vertebral circulation and should be referred to vascular neurology for screening imaging. 1
Critical Pitfalls to Avoid
Do not refer to interventional radiology first. Medical management is the evidence-based first-line treatment, with revascularization reserved only for medical therapy failures. 4 The American Heart Association explicitly recommends against pursuing revascularization as initial therapy due to insufficient evidence of benefit over medical management. 4
Do not accept ultrasound as definitive imaging. Its 70% sensitivity is inadequate for vertebral artery evaluation; insist on CTA or MRA. 1, 4
Do not use dual antiplatelet therapy routinely. The hemorrhage risk outweighs any benefit in vertebral artery occlusion. 4
Special Consideration: Traumatic Vertebral Artery Occlusion
If the occlusion resulted from cervical spine trauma (fracture, subluxation), the vascular neurologist may recommend anticoagulation with heparin followed by warfarin for at least 3 months, as anatomic healing occurs in 72-100% of dissection cases. 4 This differs from atherosclerotic occlusion management. 2