From the Guidelines
Management of suspected retrograde vertebral artery flow involves a comprehensive approach, with antiplatelet therapy as the cornerstone of medical management, and consideration of endovascular intervention or surgical revascularization in selected cases, as recommended by the 2011 ASA/ACCF/AHA/AANN/AANS/ACR/ASNR/CNS/SAIP/SCAI/SIR/SNIS/SVM/SVS guideline 1. The approach begins with confirmation of the diagnosis through imaging studies such as duplex ultrasound, CT angiography, or magnetic resonance angiography.
- Key aspects of management include:
- Antiplatelet therapy, typically with aspirin (81-325 mg daily) as first-line therapy, and consideration of dual antiplatelet therapy with aspirin plus clopidogrel (75 mg daily) for higher-risk patients 1.
- Statins to reduce atherosclerotic progression, such as atorvastatin (40-80 mg daily) or rosuvastatin (20-40 mg daily) 1.
- Blood pressure control, aiming for targets below 140/90 mmHg using appropriate antihypertensives 1.
- Endovascular intervention with angioplasty and stenting for symptomatic patients with >70% stenosis who fail medical therapy, or for subclavian steal syndrome causing retrograde flow, subclavian artery revascularization might be indicated 1.
- Regular follow-up with serial imaging every 6-12 months is recommended to monitor disease progression, as outlined in the guidelines 1. This management approach aims to improve antegrade flow, reduce embolization risk, and prevent posterior circulation ischemic events by addressing both hemodynamic compromise and thromboembolic potential, in line with the recommendations from the American College of Cardiology Foundation/American Heart Association Task Force on Practice Guidelines 1.
From the Research
Management of Suspected Retrograde Vertebral Artery Flow
The management of suspected retrograde vertebral artery flow involves several key considerations, including diagnosis, assessment of symptoms, and potential treatment options.
- Diagnosis is typically made using non-invasive techniques such as Doppler shift ultrasound 2 or transcranial Doppler ultrasonography 3.
- Assessment of symptoms is crucial, as some patients may be asymptomatic, while others may present with symptoms such as nonhemispheric or hemispheric symptoms 4.
- Treatment options may include surgical procedures to restore antegrade vertebral artery flow, although the effectiveness of these procedures in improving symptoms is not always clear 4.
- In some cases, carotid endarterectomy may be performed, and improvement in posterior circulation symptoms has been noted in some patients following this procedure 4.
- The use of anticoagulation therapy may also be considered in certain cases, such as in patients with giant cell arteritis 5.
- Endovascular intervention, including embolization, may be used to manage traumatic vertebral artery injuries, and novel approaches such as the "up and over" approach through the basilar artery may be employed in complicated cases 6.
Key Considerations
- Accurate selection of surgical candidates remains imprecise and requires not only identification of vertebrobasilar disease but also undefined tests to assure symptoms are due to these stenoses 4.
- The direction of flow and peak flow velocity in the basilar artery should be evaluated using transcranial Doppler ultrasonography 3.
- Provocative maneuvers to increase collateral flow to the arm ipsilateral to retrograde vertebral artery flow may not alter basilar artery flow velocity or direction of flow 3.
- The identification of patients with high risk of ischemia due to compromised vertebrobasilar flow is important to select adjunct treatment to immunosuppression, such as anticoagulation in giant cell arteritis 5.