M ANAGEMENT OF SYMPTOMATIC VERTEBRAL ARTERY STENOSIS Dr Sulaiman AL Shamsi Sr.consultant Vascular Surgeon Royal Hospital Oman International Vascular Coneferenec

A NDREW L. C ARNEY « My concern for the VA began with my first patient, an elderly woman who might have been simply bypassed as another senile patient, but the esteem she commanded from her large and illustrious family bespoke a remarkable woman. Although she was incontinent, agitated, and unable to remember even the names of her own children, she lamented with great anguish her inability to care for her own needs and to walk with pride among her people. After vertebral artery reconstruction, she regained all her faculties and all her self-respect. » (Advances in Neurology, Vol. 30: Diagnosis and Treatment of Brain Ischemia,edited by A. L. Carney and E. M. Anderson. Raven Press, New York © 1981.)

A NATOMY OF THE VERTEBRAL ARTERY 4 segments. Anatomic variants, VA > carotid. Lt, 5% directly from the aortic arch diameter left > in 50% or equal to in 25% of individuals

E PIDEMIOLOGY Difficult to visualize the origins of VA. 20% of posterior circulation stroke (Cloud and Markus, 2003) Recent studies have shown that the early risk of recurrent stroke after TIA and minor stroke is as high as 8–10% in the first week. (Rothwell et al., 2006) New England Medical Center Posterior Circulation Registry: - 82 of 407 patients with ischemia affecting the posterior circulation had >50% stenosis ECVA. Annual stroke rates = 8 %

C LINICAL P RESENTATION dizziness, vertigo, diplopia, perioral numbness, blurred vision, tinnitus, ataxia, bilateral sensory deficits, syncope,

E VALUATION

Based on the 2011 ASA/ACCF/AHA/AANN/AANS/ACR/ CNS/SAIP/SCAI/SIR/SNIS/SVM/SVS Guideline on the Management of Patients With Extracranial Carotid and Vertebral Artery DiseaseDeveloped in Collaboration With the American Academy of Neurology and Society of Cardiovascular Computed Tomography January 2011

E VALUATION Vertebral Artery Imaging Class I 1. Noninvasive imaging by CTA or MRA for detection of vertebral artery disease o should be part of the initial evaluation of patients with neurological symptoms referable to the posterior circulation and those with subclavian steal syndrome. (Level of Evidence: C)

o should be performed in patients with asymptomatic bilateral carotid occlusions or unilateral carotid artery occlusion and incomplete circle of Willis. (Level of Evidence: C) o is recommended over ultrasound imaging for evaluation of the vertebral arteries in patients whose symptoms suggest posterior cerebral or cerebellar ischemia. (Level of Evidence: C)

Class IIa 1. In patients with symptoms of posterior cerebral or cerebellar ischemia 1. In patients with posterior cerebral or cerebellar ischemic symptoms who may be candidates for revascularization, catheter-based contrast angiography can be useful to define vertebral artery pathoanatomy when noninvasive imaging fails to define the location or severity of stenosis. ( Level of Evidence: C )

3- In patients who have undergone vertebral artery revascularization, serial noninvasive imaging of the extracranial vertebral arteries is reasonable at intervals similar to those for carotid revascularization. ( Level of Evidence: C ) CTA and MRA were associated with higher sensitivity (94%) and specificity (95%) than duplex ultrasonography (sensitivity 70%), and CTA had slightly superior accuracy.

M EDICAL T HERAPY 1. Medical therapy and lifestyle modification ( Level of Evidence: B ) 1. Patients with atherosclerotic VA should receive antiplatelet therapy with aspirin (75 to 325 mg daily) to prevent MI and other ischemic events. ( Level of Evidence: B ) 1. Antiplatelet drug therapy is recommended for patients who sustain ischemic stroke or TIA associated with extracranial vertebral atherosclerosis. ( Level of Evidence: B )

S URGICAL MANAGMENT

S URGICAL MANAGEMENT Indications for surgery on the first part of the vertebral artery are relatively rare. No randomized trials. Surgical options: endarterectomy, bypass, or transposition. The feasibility of endarterectomy and vessel reconstruction with favorable outcomes. ( Ramon Bergeur, Presented at the Forty-seventh Scientific Meeting of theInternational Society for Cardiovascular Surgery, NorthAmerican Chapter, Washington, DC, Jun 8–9, 1999.

S URGICAL MX CONT …… Proximal vertebral artery reconstruction, early complication rates of 2.5% to 25% and perioperative mortality rates of 0% to 4%. Distal vertebral artery reconstruction, mortality rates 2% to 8% Cumulative Kaplan-Meier survival rate was 89.0% at 5 years and 75.4% at 10 years Significant vertebrobasilar symptom-free rate was 94.0% at 5 years and 92.8% at 10 years. ( Edouard Kieffer Distal vertebral artery reconstruction: Long-term outcome 2002 )

E NDOVASCULAR I NTERVENTIONS FOR V ERTEBRAL A RTERY D ISEASE

There is insufficient evidence from randomized trials. In a review of 300 interventions for proximal vertebral artery stenosis Death 0.3% The risk of periprocedural neurological complications 5.5% Risk of posterior stroke 0.7% at a mean follow-up of 14.2 months

Restenosis in 26% of cases (0% to 43% after a mean of 12 months (3 to 25 months) Among 170 angioplasty with distal vertebrobasilar disease, neurological complications developed in 24%, but the rate approached 80% in cases of urgent vertebrobasilar revascularization. ( Eberhardt et al 2006,JVS ) The annual stroke risk after angioplasty for distal vertebrobasilar disease is approximately 3%. Drug Eluting Stents ? The restenosis rate was 21% at the VO in 14 months. ( Fields JD Interv Neuroradiol.2011)

CAVATAS, the only randomized study to date to compare outcomes after endovascular and medical treatment for patients with vertebral artery stenosis, included only 16 such patients, and because no patient in either arm had recurrent vertebral basilar territory stroke by 8 years after randomization, there was no difference in outcomes among those treated by stenting or medical therapy.

W HAT IS NEW ? VAST : The primary aim is to assess whether stenting for symptomatic vertebral artery stenosis ≥ 50% is feasible and safe. Secondary aim is to assess the rate of new vascular events in the territory of the vertebrobasilar arteries in patients with symptomatic vertebral stenosis ≥ 50% on best medical therapy with or without stenting. Awaited

C ONCLUSION Vertebral artery stenosis is an important aetiology of posterior circulation stroke. At present, there is not enough evidence to recommend endovascular stenting over medical therapy. If the above studies show that stenting is superior to medical management, they may help to establish endovascular stenting as the standard of care for symptomatic VA stenosis. In the mean time, maximal medical therapy should be tried first. For medically refractory patients, endovascular stenting is recommended.

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