Article Text
Abstract
We present a 56-year-old man who presented with bilateral vertebral artery occlusions and recurrent transient ischemic attacks and strokes despite maximal medical therapy. A long-segment extracranial right vertebral occlusion was noted and successfully reconstructed with four drug-eluting stents. The patient has been symptom free for 3 months and does not exhibit restenosis on follow-up angiography. Stenting and angioplasty of a long-segment vertebral artery occlusion is technically feasible in select cases.
- Artery
- stenosis
- stroke
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The prevalence of extracranial vertebral artery stenosis is not known, although recent autopsy studies suggest that the incidence is nearly 13% in patients with fatal strokes1 and 32% in patients presenting with stroke or transient ischemic attack of the posterior circulation.2 Roughly a quarter of patients with extracranial vertebral artery stenosis are noted to have bilateral disease.2 Patients presenting with symptomatic total bilateral vertebral artery occlusions are not common but pose a challenging dilemma to clinicians. Options for this condition include: endovascular reconstruction of the occluded segment of the vertebral artery3 or surgical bypass above the occluded segment.4 We present a patient who presented with stroke and recurring transient ischemic attacks due to bilateral vertebral artery occlusion who was successfully treated with stenting and angioplasty of a long-segment occlusion.
Case report
A 56-year-old man with a history of tobacco abuse, hypertension and hyperlipidemia who presented with diplopia and dysarthria with a similar episode that had occurred 6 weeks earlier. The patient was noted to have bilateral vertebral artery occlusions on magnetic resonance angiogram and acute infarcts involving the pons and midbrain on MRI. He was placed on dual anti-platelet therapy with aspirin 325 mg daily and clopidogrel 75 mg daily along with a lipid lowering agent. Despite maximal medical management, the patient continued to note daily spells of ataxia and dysarthria that were exacerbated by postural changes. He was referred to our institution for further management. A cerebral angiogram was performed that revealed a total occlusion of the left vertebral artery and a long-segment occlusion of the extracranial right vertebral artery that reconstituted via muscular branches and thyrocervical branches (figure 1). The intracranial posterior circulation remained patent due to these collaterals. No posterior communicating arteries were present. After a detailed discussion regarding surgical and endovascular options, we proceeded with the endovascular approach.
Technique
The procedure was performed under general anesthesia after confirmation of adequate platelet inhibition using optical light aggregometry with the patient on aspirin and clopidogrel prior to the procedure. Intravenous heparin was administered to maintain an activated clotting time of between 250 and 300 s for the procedure. After femoral artery puncture, the diagnostic catheter was exchanged for a 6 Fr 80 cm Cook Shuttle sheath that was positioned in the right subclavian artery proximal to the vertebral artery ostium. A 6 Fr guiding catheter was placed coaxially through the shuttle sheath into the stump of the vertebral artery ostium. A RapidTransit microcatheter (Cordis Corp., Miami Lakes, Florida, USA) was navigated over a 0.018 inch wire to traverse the stump. The 0.018 inch wire was removed and a 0.014 inch microwire was used to navigate across the long-segment occlusion to the patent vertebral artery at the level of the collaterals. After the microcatheter was advanced over the microwire across the occluded segment, an exchange length 0.014 inch microwire was used to remove the microcatheter. An intravascular ultrasound probe was navigated across the occlusion to ensure that the wire did not enter the false lumen and also to assess the degree of thrombus burden. This technique confirmed that the wire was in the true lumen and the lesion was atherosclerosis without significant thrombus burden. Over this microwire a total of four Xience everolimus eluting stents (4.0×23 mm x 1, 4.0×18 mm×3) were placed in a telescoping manner to cover the entire segment of the occlusion. An angiographic run was performed after deployment of the stents confirming patency of the vertebral artery (figure 2). On intracranial projections there was a stenosis noted of the right vertebro-basilar junction that was moderate and left untreated. The patient was discharged home the next day on aspirin 325 mg daily and clopidogrel 75 mg daily for at least 12 months. The patient underwent a follow-up angiogram at 3 months that showed no evidence of restenosis and the muscular collaterals no longer present (figure 3). At his 6 month follow-up he remains symptom free and has returned to full employment.
Discussion
The current case report demonstrates that treatment of long-segment extracranial chronic vertebral artery occlusions is feasible. The concerns with the endovascular approach for this condition is the inability to traverse a long segment, rupture or dissection of the vertebral artery and stroke due to distal embolization. A prior report has described the use of flow reversal to prevent distal embolization during treatment of this condition3 similar to that reported in carotid revascularization procedures. The efficacy of distal protection or proximal flow reversal technologies for carotid stenting procedures is unproved. MRI studies comparing patients treated with distal protection and without protection did not reveal any differences in embolic debris.5 Moreover, treatment of chronic carotid occlusions has been performed safely without utilization of protection devices.6
Surgical bypass or endarterectomy has been reported for vertebral artery occlusions, but the surgical morbidity appears to be significant.7 Unfortunately, such procedures are not commonly performed and thus we opted to reserve this as an option if the endovascular option failed.
There is a concern for the durability of placing stents in a long segment. We utilized drug-eluting stents in the hope of reducing the risk of restenosis. Moreover, the rates of restenosis in the coronary arteries appear to be associated with smaller vessel diameter as opposed to lesion length. Lesion length appears to have a higher correlation with periprocedural rates of myocardial infarction.8 The use of multiple drug-eluting stents has been reported for lesions >50 mm with low rates of restenosis.9 The treatment of a chronic vertebral artery occlusion is technically feasible and may be performed in certain clinical situations, but further study is required to assess durability and complication rates of the procedure.
Footnotes
Competing interests Rishi Gupta, MD: Consultant/Scientific Advisory Board Concentric Medical, Consultant/Scientific Advisory Board CoAxia.
Patient consent Obtained.
Ethics approval This study was conducted with the approval of the Cleveland Clinic IRB.
Provenance and peer review Not commissioned; externally peer reviewed.