What is the treatment for vertebrobasilar insufficiency?

Treatment of Vertebrobasilar Insufficiency

Antiplatelet therapy is the first-line treatment for vertebrobasilar insufficiency, with aspirin 81-325 mg daily or combination aspirin plus extended-release dipyridamole recommended immediately upon diagnosis, alongside aggressive cardiovascular risk factor modification. 1, 2

Medical Management Algorithm

Initial Antiplatelet Therapy

• Start aspirin 81-325 mg daily immediately for all symptomatic patients with vertebrobasilar insufficiency 2
• Alternative options include clopidogrel 75 mg daily or ticlopidine 250 mg twice daily, with ticlopidine showing superiority to aspirin for secondary prevention in posterior circulation disease 1
• Combination therapy with aspirin plus extended-release dipyridamole reduces vertebrobasilar territory stroke/TIA from 10.8% to 5.7% compared to placebo, making it a preferred option for enhanced protection 1, 2

Anticoagulation for Specific Scenarios

• For acute ischemic syndromes with angiographic evidence of thrombus in the extracranial vertebral artery, initiate anticoagulation for at least 3 months regardless of whether thrombolytic therapy is used 1, 2
• Start with intravenous heparin, then transition to oral warfarin after stabilization 3
• The WASID trial demonstrated that aspirin and warfarin are equally efficacious after initial noncardioembolic ischemic stroke 1
• After the 3-6 month anticoagulation period, transition to indefinite antiplatelet therapy 3

Cardiovascular Risk Factor Modification

• Apply the same aggressive risk reduction strategies used for carotid atherosclerosis, including statin therapy for lipid management, blood pressure control to target <140/90 mmHg, smoking cessation, diabetes management with HbA1c <7%, and lifestyle modifications 2, 3
• This comprehensive approach addresses the underlying atherosclerotic process that causes approximately 20% of posterior circulation strokes 1

Diagnostic Evaluation

Imaging Requirements

• Obtain CTA or contrast-enhanced MRA as initial noninvasive imaging, which have 94% sensitivity and 95% specificity for detecting vertebral artery stenosis 1, 2
• Ultrasonography has inadequate sensitivity at only 70% and should not be relied upon alone 1, 2
• Catheter-based angiography is required before any revascularization procedure because neither MRA nor CTA reliably delineates the origins of the vertebral arteries 1, 2
• MRI of the brain is more sensitive than CT for detecting posterior fossa infarcts 1

Clinical Symptoms to Assess

• Look specifically for dizziness, vertigo, diplopia, perioral numbness, blurred vision, tinnitus, ataxia, bilateral sensory deficits, and syncope 1
• Distinguish vertebrobasilar insufficiency from mimics including cardiac arrhythmias, orthostatic hypotension, and vestibular disorders through targeted cardiovascular and vestibular examination 1
• Symptoms upon head turning suggest midportion vertebral artery lesions with transverse process impingement 1

Revascularization Considerations

When to Consider Intervention

• Reserve revascularization only for patients with persistent or recurrent ischemic symptoms despite optimal medical therapy 2, 4
• There is insufficient evidence from randomized trials that endovascular or surgical management is superior to best medical management 2
• No therapeutic modality has been proven unequivocally beneficial in randomized trials 1

Endovascular Approach Risks

• Endovascular stenting for proximal vertebral artery stenosis carries a 0.3% mortality rate, 5.5% periprocedural neurological complications, and 0.7% posterior stroke rate at mean 14.2 months follow-up 2
• Restenosis occurs in 26% of cases after mean 12 months, though not consistently correlated with recurrent symptoms 2

Surgical Approach Risks

• Operations are rarely performed, with early complication rates of 2.5-25% and perioperative mortality of 0-4% 2
• Proximal vertebral artery reconstruction has 0-4% mortality, while distal reconstruction has 2-8% mortality 2
• Intracranial bypass surgery carries 3-12% mortality and 22-55% neurological/systemic complication rates 2
• Patients with vertebrobasilar insufficiency are at higher perioperative risk from revascularization compared to similar anterior circulation lesions 1

Special Clinical Scenarios

Subclavian Steal Syndrome

• For symptomatic posterior cerebral or cerebellar ischemia caused by subclavian artery stenosis/occlusion, extra-anatomic carotid-subclavian bypass is recommended in the absence of factors predisposing to surgical morbidity 2
• Percutaneous endovascular angioplasty and stenting is reasonable for high surgical risk patients 2

Vertebral Artery Dissection

• Anticoagulation for 3-6 months is recommended, then transition to long-term antiplatelet therapy 3
• Anatomic healing occurs in 72-100% of dissection cases 3
• CTA has the highest sensitivity (100%) for detecting dissection, followed by MRA (77%) and Doppler ultrasound (71%) 1

Critical Pitfalls to Avoid

• Do NOT use dual antiplatelet therapy (aspirin plus clopidogrel) routinely, as hemorrhage risk outweighs benefit 3
• Do NOT confuse hypoplastic vertebral artery (congenital small diameter) with stenosis (acquired atherosclerotic narrowing), as management differs significantly 5
• Do NOT pursue revascularization in asymptomatic patients, regardless of imaging findings, as no evidence supports intervention without symptoms 2, 5
• Do NOT rely on ultrasound alone for vertebral artery evaluation given its inadequate 70% sensitivity 1, 3