Severe Vertebral Artery Stenosis Research Articles

Effect of haemodynamics on the risk of ischaemic stroke in patients with severe vertebral artery stenosis

ObjectivesEndovascular treatment strategies to optimise individualised care for patients with vertebral artery (VA) stenosis need to be revisited. This study aimed to investigate the relationship between net VA flow volume...

Optical Coherence Tomography of Plaque Erosion and Thrombus in Severe Vertebral Artery Stenosis.

A 69-year-old male presented with medically refractory vertebrobasilar insufficiency and paroxysmal subjective dizziness for six months. Severe stenosis of a dominant left V2 vertebral artery segment was identified on digital subtraction angiography (DSA) with an irregular intraluminal filling defect immediately above the stenosis. Optical coherence tomography (OCT) demonstrated a normal lumen at the distal end, with red thrombus detected distal to the stenosis. Atherosclerotic plaque containing fibro-lipid was also identified and treated with a drug-eluting stent. Distal red thrombi were not covered by stenting, indicating embolization risk in the future. Clear posterior fossa symptoms occurred after intervention, and treatment with a standard dual antiplatelet regimen and statin therapy was prescribed for one year. Six months after treatment, the symptoms improved, and six-minute walking distances were successful with no gait impairment. To our knowledge, this is the first V2 segment stenosis assessed by OCT imaging before and after stenting, indicating an intact fibrous cap with thrombus formation, as well as plaque erosion. Understanding the role and careful use of OCT may improve the identification of red thrombus and plaque erosion when clinically indicated.

Endovascular treatment of symptomatic severe vertebral artery stenosis

About 25%-40% of ischemic stroke is in the posterior circulation, in which 20% of posterior circulation stroke is caused by vertebral artery stenosis. Patients with symptomatic vertebral artery stenosis have a high risk of recurrent stroke. At present, the treatments of vertebral artery stenosis include medication, open surgery and interventional therapy. In this paper, the endovascular treatment of vertebral artery stenosis is reviewed, especially the progress of endovascular treatment is expounded, in order to promote the development of its treatment. Key words: Brain ischemia; Vertebral artery stenosis; Angioplasty, balloon; Drug-eluting stents; Atherectomy

Ultrasound Criteria for Assessment of Vertebral Artery Origins

We sought to validate ultrasound as a reliable means of assessing vessel stenosis of vertebral artery origins. We reviewed 1,135 patient charts with ultrasound of the posterior circulation performed in 2008-2015 in a single hospital. Inclusion criteria for native vessels consisted of ultrasound and digital subtraction angiography (DSA) performed within 3 months. Patients with indwelling stents were analyzed separately from native vessels. Using DSA as the gold standard, we determined sensitivity and specificity of ultrasound in detecting occlusion at vertebral artery origin. All patients with nonoccluded native vertebral artery origins were evaluated for degree of stenosis on DSA, and compared to mean flow velocity (MFV), peak systolic velocity (PSV), and end-diastolic velocity (EDV) on ultrasound. Among 218 vertebral artery origins in 139 patients evaluated, ultrasound showed sensitivity of 85.7% (95% confidence interval (CI): 69.7-95.2%) for occlusion and specificity of 99.5% (95%CI: 96.9-99.9%). Among 126 arteries without occlusion, <50% stenosis had average MFV (39±19 cm/s), 50-69% stenosis had average MFV (68±35 cm/s), and severe (70-99%) stenosis had average MFV (120±93 cm/s) (P<.001). MFV cutoff value of 44 cm/s corresponded to 77% sensitivity and 70% specificity to detect vertebral artery origin stenosis >50% (C-statistic: .81). PSV value of 97 cm/s corresponded with 72% sensitivity and 70% specificity to detect >50% stenosis (C-statistic: .77). MFV cutoff value of 60 cm/s corresponded with 70% sensitivity and 82% specificity to predict 70-99% stenosis (C-statistic: .83). PSV cutoff value of 110 cm/s corresponded with 80% sensitivity and 72% specificity to predict 70-99% stenosis (C-statistic: .84). Ultrasound has good sensitivity and excellent specificity for detecting vertebral origin occlusion. Flow velocity can be used to screen for severe stenosis of vertebral artery at origin.

Severe vertebral artery stenosis treated by directional atherectomy

We report the outcomes of directional atherectomy using a distal protective device and drug-coated balloon angioplasty in four patients with severe atherosclerotic vertebral artery stenosis. All cases were clinically successful with complete resolution of the symptoms. Immediate and postoperative results showed a good technical success. These results suggest that vertebral artery stenosis treated with directional atherectomy is technically feasible and may be a safe and effective option when performed by experienced endovascular surgeons.

Commentary on paper “Severe vertebral artery stenosis treated by directional atherectomy” by Yongquan Gu, et al. Vasc Invest Ther 2018;1:110-4

Commentary on paper “Severe vertebral artery stenosis treated by directional atherectomy” by Yongquan Gu, et al. Vasc Invest Ther 2018;1:110-4

Asymptomatic Extracranial Vertebral Artery Disease in Patients with Internal Carotid Artery Stenosis.

Extracranial vertebral artery disease is seen in patients with internal carotid artery stenosis, although the clinical significance is not well understood. To determine the prevalence and natural history of extracranial vertebral artery disease in patients with recently symptomatic internal carotid artery stenosis. We analyzed data collected for patients with recently symptomatic internal carotid artery stenosis in the Stent-Protected Angioplasty vs Carotid Endarterectomy trial. We used Cox proportional hazards analysis to compare the relative risk of various endpoints (any stroke, ipsilateral stroke, and death) between the 3 categories of extracranial vertebral artery disease (normal/hypoplastic, moderate/severe stenosis, occlusion) adjusting for age, gender, severity of internal carotid artery stenosis at baseline (<70% and ≥70%), allocated procedure (carotid angioplasty and stent placement or carotid endarterectomy) and hypertension. Moderate to severe stenosis and occlusion of 1 of both extracranial vertebral arteries were diagnosed in 152 (12.9%) and 57 (4.8%) of 1181 subjects, respectively. Comparing subjects with normal or hypoplastic vertebral artery, there was nonsignificant 30%, 40%, and 50% higher risk of any stroke (hazard ratio [HR] 1.3, 95% confidence interval [CI] 0.7-2.3), ipsilateral stroke (HR 1.4, 95% CI 0.7-2.5), and death (HR 1.5, 95% CI 0.7-3.1) among subjects with moderate to severe vertebral artery stenosis after adjusting for potential confounders. There may be an increased risk of stroke and death in patients with symptomatic internal carotid artery stenosis with concurrent asymptomatic extracranial vertebral artery stenosis.

Abstract WP144: Ultrasound Criteria for Assessment of Vertebral Artery Origins

Introduction: We sought to validate ultrasound as a reliable means of assessing vessel stenosis of vertebral artery origins. Methods: We reviewed 1135 patient charts with ultrasound of the posterior circulation performed 2008-2015 in our Neurovascular Laboratory Imaging Institute. Inclusion criteria consisted of ultrasound and digital subtraction angiography (DSA) performed within three months as well as absence of prior stent placement, resulting in 218 vessels in 133 patients. Using DSA as the gold standard, we determined sensitivity and specificity of ultrasound in detecting occlusion at vertebral artery origin. All patients with non-occluded vertebral artery origins without stent were evaluated for degree of stenosis on DSA, and compared to mean flow velocity (MFV) on ultrasound. Results: Among 218 vertebral artery origins evaluated, ultrasound showed sensitivity of 85.7% (95% confidence interval (CI) 69.7-95.2%) for occlusion and specificity of 99. 5% (95%CI 96.9-99.9%). Among 126 arteries without occlusion, &lt;50% stenosis had average MFV 39.5 cm/s (SD 19.9), 50-69% stenosis had average MFV 69.2 cm/s (SD 34.7), and severe 70-99% stenosis had average MFV 129 cm/s (SD 30.65), p&lt;0.001 by Kruskal-Wallis test. For detecting ≥70% stenosis, c-statistic of ROC curve was 0.81, and MFV of 70 cm/s has 82% sensitivity and 88% specificity of ≥70% stenosis. Conclusion: Ultrasound has good sensitivity and excellent specificity for detecting vertebral origin occlusion. Flow velocity can be used to screen for severe stenosis of vertebral artery at origin.

Abstract TP127: Prevalence and Clinical Significance of Asymptomatic Extracranial Vertebral Artery Disease in Patients With Symptomatic Internal Carotid Artery Stenosis: Analysis of Stent-protected Angioplasty versus Carotid Endarterectomy (SPACE) Trial

Background: Extracranial vertebral artery disease is seen in patients with internal carotid artery stenosis although the clinical significance not well understood. Methods: We analyzed data that was collected as part of the Stent-Protected Angioplasty versus Carotid Endarterectomy (SPACE) trial which recruited patients with recently symptomatic internal carotid artery stenosis. We used Cox proportional hazards analysis to compare the relative risk of various endpoints between the three categories of extracranial vertebral artery disease (normal/hypoplastic, moderate/severe stenosis, and occlusion). The multivariate analyses were adjusted for age, gender, basic demographics and severity of carotid stenosis. Results: Of the 1181 subjects who had extracranial vertebral artery ultrasound evaluation, moderate to severe stenosis and occlusion of one of both extracranial vertebral arteries was diagnosed in 152(12.9%) and 57(4.8%) subjects, respectively. During the mean follow up period (±SD) of 22.1±7.1 months 102(8.6%) and 60(5.1%) experienced a stroke or died, respectively. Compared with subjects with normal or hypoplastic vertebral artery, there was a non-significant 30% higher risk of any stroke among subjects with moderate to severe vertebral artery stenosis (relative risk [RR]1.3, 95% confidence interval [CI]0.7-2.3) after adjusting for potential confounders. There was a 40% and 50% higher risk of ipsilateral stroke (RR 1.4, 95% CI0.7-2.5) and death (RR 1.5, 95% CI 0.7-3.1) among subjects with moderate to severe vertebral artery stenosis after adjusting for potential confounders. In Kaplan Meir analysis, the estimated 1 and 2 year stroke free survival for subjects with moderate to severe vertebral artery stenosis was 88% (standard error [SE]2.6%). In comparison, the estimated 1 and 2 year stroke free survival for subjects with normal or hypoplastic vertebral artery was 92.5%(SE0.8%)and 91.6%(SE0.9), respectively. Conclusions: There appears to be an increased risk of stroke and death in patients with symptomatic internal carotid artery stenosis with concurrent asymptomatic extracranial vertebral artery stenosis.

Subclavian and Vertebral Artery Angioplasty - Vertebro-Basilar Insufficiency: Clinical Aspects and Diagnosis

ABSTRA C T BACKGROUND: Percutaneous transluminal angioplasty (PTA) for significant stenosis involving the origin of the vertebral artery is now a well established treatment for selected patients when posterior cerebral arterial circulation is compromised. We demonstrate from our short and long-term results, after transluminal treatment of subclavian and vertebral artery stenosis, the feasibility and safety of treatment with balloon angioplasty and stenting. PATIENTS AND METHODS: A total of 181 patients underwent endovascular treatment and were divided into two groups. In group A, we treated patients with chronic vertebrobasilar insufficient. In this group, 21 patients with severe vertebral artery stenosis had also concomitant severe stenosis in other supra aortic arteries. In group B we treated patients with subclavian steal syndrome. In this group 21 patients presented with coexistence of severe stenosis in other supra aortic arteries. Stent patency of subclavian and vertebral artery during follow up was assessed by duplex scan and physical examination, with comparison of brachial blood pressure of both arms especially in patients with subclavian stenosis. Digital angiography was performed in available patients. Cerebral oximetry and intracranial Doppler were used to determine the group of patients that we had to treat with balloon angioplasty and stenting. RESULTS: Successful stenting was achieved in all cases. There were no complications. The primary stenting patency during follow-up (mean 8.6 months) was 98.6%. With use of intracranial Doppler we found 31 patients with higher blood flow in the basilar artery after stenting and 24 patients were found with increased brain regional oxygen saturation in the anterior cerebral artery. CONCLUSION: Endovascular treatment of subclavian and vertebral arteries with balloon angioplasty and stenting was found to be necessary in certain cases and a less invasive alternative to surgical repair. Long-term results must still be confirmed in further studies.

Imaging of vertebral artery stenosis: a systematic review

Background and purpose:Posterior circulation stroke accounts for 20% of ischaemic strokes. Recent data suggest that the early stroke recurrence risk is high and comparable with carotid artery disease. Vertebral artery...

Transcranial color Doppler flow imaging in detecting severe stenosis of the intracranial vertebral artery: a prospective study

Objective The aims of this prospective study were to investigate the manifestations of the hemodynamics and morphology of a normal intracranial vertebral artery (VA) and diffusely severe or localized critical vertebral artery stenosis (VAS) on transcranial color Doppler flow imaging (TCDFI) and to discuss the criteria of TCDFI in detecting severe VAS. Methods There were 30 patients suspected of having an intracranial VAS in a patient group and 30 healthy volunteers in a control group. All the patients underwent both TCDFI and digital subtraction angiography (DSA). The intracranial VA was imaged through the suboccipital window by TCDFI. The size and tortuousness of the vessels were observed. The hemodynamics of those vessels were measured by means of peak systolic velocity (PSV) and pulsatility index (PI). Results In the control group, the VA junction with basilar artery appeared as Y shaped and filled with well-distributed blue coded on color imaging, which showed flow below the baseline with fast early systolic acceleration, and normal PSV ranged from 0.42 to 0.80 m/s on pulse wave Doppler. In the patients with diffusely severe VAS (>70% lumen reduction, the length of plaque >1 cm or multiple plaques) or localized critical VAS (>90% lumen reduction) diagnosed by TCDFI and confirmed with DSA, a narrowed and tortuous VA was demonstrated with minimal flow on color Doppler imaging and decreased 50% of normal PSV and PSV <0.30 m/s accompanied by slow early systolic acceleration on Doppler spectrum. There was a significant difference ( P<.05 or P<.01) in the hemodynamic parameters (PSV and PI) between patients with severe VAS and healthy subjects. Conclusion TCDFI is a useful noninvasive tool in assessing the hemodynamics of intracranial arteries. The sensitivity was 90.9% and the specificity was 75.0% by using PSV <0.30 m/s and 50% reduction of normal PSV as low cutoff criteria in the diagnosis of diffusely severe or localized critical VAS with TCDFI.

Percutaneous transluminal angioplasty and stenting for vertebral artery stenosis

Surgery for vertebral artery stenosis is technically difficult, potentially hazardous and is not considered in most centres. There is growing evidence from case series that vertebral artery stenosis may be treated endovascularly by percutaneous transluminal angioplasty and stenting. This may be a feasible alternative to surgery to relieve symptoms caused by significant stenosis. The objective of this review was to assess the safety and efficacy of vertebral artery percutaneous transluminal angioplasty, with or without stenting, combined with medical care, compared to medical care alone, in patients with vertebral artery stenosis. We searched the Cochrane Stroke Group's trials register (last searched 28 July 2004). In addition we searched the following bibliographic databases: Cochrane Central Register of Controlled Trials (The Cochrane Library, Issue 3, 2002), MEDLINE (1966 to July 2004), EMBASE (1980 to July 2004), and Science Citation Index (1981 to July 2004). We also contacted researchers in the field, and balloon catheter and stent manufacturers. We selected randomised trials of endovascular treatment of vertebral artery stenosis combined with best medical therapy, compared with best medical therapy alone, in patients with symptomatic or asymptomatic vertebral artery stenosis. Two reviewers independently applied the inclusion criteria, extracted data and assessed trial quality. One completed randomised trial was found. In one subgroup of this trial, 16 patients with symptomatic severe vertebral artery stenosis were randomised to endovascular treatment (n = 8) or medical treatment alone (n = 8). There were no strokes in any arterial territory or deaths from any cause in either group within 30 days of treatment (endovascular group) or 30 days of randomisation (medical group). In the endovascular group, two patients had a posterior circulation TIA at the time of the procedure. In the endovascular group, the mean vessel stenosis at follow up was 47% (range 0% to 80%). Patients were followed up for a mean of 4.5 years in the endovascular group and 4.9 years in the medical group. There were no further vertebrobasilar territory strokes in either group for the duration of follow up. Morbidity and mortality was related to carotid and coronary artery disease in this study. There is currently insufficient evidence to assess the effects of percutaneous transluminal angioplasty with or without stenting or primary stenting for vertebral artery stenosis.

Atherosclerotic Vertebral Artery Disease in the Neck.

Atherosclerotic lesions are very common at the origin and first few centimeters of the vertebral artery in the neck. These lesions are often missed when using noninvasive diagnostic strategies. These lesions cause transient hypoperfusion and transient ischemic attacks, characterized mostly by vestibulocerebellar symptoms. Strokes are caused by embolism from these lesions. Patients with nonstenosing vertebral artery plaques should be treated with statins and antiplatelet agents. Symptomatic patients who have had embolism from an occluded vertebral artery should be treated with heparin followed by warfarin for a period of 4 to 12 weeks. Antiplatelet agents can then be given. The optimal treatment of asymptomatic and symptomatic patients with severe vertebral artery stenosis is unclear. Statins and warfarin are recommended for patients with concurrent stenotic lesions of the contralateral extracranial vertebral artery, the intracranial vertebral or basilar arteries, or the anterior circulation arteries. Balloon angioplasty or stenting will likely prove superior to surgery in those patients with severe stenosis who do not respond to medical treatment.

Posterior communicating artery visualization in predicting results of carotid endarterectomy for vertebrobasilar insufficiency

Retrospectively, 51 patients who related two or more signs or symptoms of vertebrobasilar insufficiency and possessed concomitant carotid arterial disease were identified. The patient population was separated into two groups based on the presence or absence of an angiographically visualized posterior communicating artery during selective carotid artery injection. All patients had undergone unilateral or staged bilateral carotid endarterectomy. Comparison of postoperative clinical outcome with intracerebral angiographic findings exhibited statistically significant improvement in favor of those patients with at least one visualized posterior communicating artery. There was a greater likelihood of severe vertebral artery stenosis in those patients whose symptoms were not relieved by carotid endarterectomy.