Vertebral artery hypoplasia as an independent risk factor of posterior circulation atherosclerosis and ischemic stroke

Congenital right subclavian artery aneurysm resection in a 30-year-old woman

Right-sided subclavian artery aneurysms (SAAs) are exceedingly rare. The most common cause of intrathoracic SAAs is atherosclerosis; however, causes can also include infection, trauma, cystic medial degeneration, Marfan syndrome, and Takayasu arteritis. Symptoms present most commonly with compression of surrounding structures, although adverse events, including rupture, thrombosis, and embolization, can also occur. We present a case of a 30-year-old woman with an asymptomatic, 15-mm, right-sided SAA, which was successfully resected with subsequent end-to-end primary anastomosis.

Percutaneous Transluminal Angioplasty for Atherosclerotic Stenosis of Vertebral Artery Origin

Background: In patients with vertebral artery origin (VAO) stenosis and concomitant stenoses of other cerebral feeding arteries, data on the risk of percutaneous transluminal angioplasty (PTA) alone and with stent placement (PTAS) for VAO stenosis are limited. We aimed to determine how the presence of polystenotic lesions in other cerebral feeding arteries and concomitant carotid artery stenting (CAS) affect the periprocedural risk and long-term effect of PTA/S for atherosclerotic VAO stenosis. Methods: In a retrospective descriptive study, consecutive patients treated with PTA/S for ≥70% VAO stenosis were divided into groups with isolated VAO stenosis and multiple stenoses. We investigated the rate of periprocedural complications in the first 72 h and the risk of restenosis and ischemic stroke (IS)/transient ischemic attack (TIA) during the follow-up period. Results: In a set of 66 patients aged 66.1 ± 9.1 years, polystenotic lesions were present in 56 (84.8%) patients. 21 (31.8%) patients underwent endovascular treatment for stenosis of one or more other arteries in addition to VAO stenosis (15 underwent CAS). During the periprocedural period, no patient suffered from an IS or died, and, in the polystenotic group with concomitant CAS, there was one case of TIA (1.6%). During a mean follow-up period of 36 months, we identified 8 cases (16.3%) of ≥50% asymptomatic VA restenosis, and, in the polystenotic group, 4 (8.9%) cases of IS. Conclusion: The presence of severe polystenotic lesions or concomitant CAS had no adverse effect on the overall low periprocedural risk of PTA/S of VAO stenosis or the risk of restenosis during the follow-up period.

Anatomy of vertebral artery hypoplasia and its relationship with clinical implications: a systematic review and meta-analysis of prevalence

PURPOSE

The vertebral artery (VA) is a vital branch of the subclavian artery, coursing through the transverse foramina of the cervical vertebrae, and playing a crucial role in irrigating the posterior region of the arterial cerebral circle, also known as the Polygon of Willis. Among the various possible alterations that can affect the VA, vertebral artery hypoplasia (HAV) emerges as a significant variant. This study aims to discern the anatomical features of HAV and its correlation with the clinical conditions of the posterior cerebral circulation.

METHODS

The databases Medline, Scopus, Web of Science, Google Scholar, CINAHL, and LILACS were searched until January 2024. Two authors independently performed the search, study selection, and data extraction. Methodological quality was evaluated with an assurance tool for anatomical studies (AQUA). Pooled prevalence was estimated using a random effects model.

RESULTS

A total of 24 studies met the established selection criteria, with a total of 8847 subjects. In this study, 6 articles were included for the meta-analysis with a total of subjects. The average prevalence of VAH reported in each study was 11% (95% CI 10-12%); the studies had a heterogeneity of 41% based on the funnel plot and a low risk of bias.

CONCLUSION

The prevalence of VAH is low, but in the presence of this condition, the changes are mainly in diameter rather than morphological. If it is present, some clinical safeguards must be taken to avoid complications such as stroke.

The association between vertebral artery hypoplasia and fetal-type variants of the posterior cerebral artery with imaging findings among patients with posterior circulation stroke: A single-center cross-sectional study

Background and Aim

The present study investigated the correlation between vertebral artery hypoplasia and fetal-type variations of posterior cerebral arteries with stroke patterns and imaging findings in individuals with posterior circulation ischemic stroke.

Methods

In this cross-sectional study, patients with symptoms of acute ischemic stroke in the posterior circulation system referred to Ghaem Hospital in Mashhad between 2016 and 2022 were investigated. Demographic data, including age, gender, systemic diseases, history of previous stroke or transient ischemic attacks, and clinical manifestations of patients, were recorded using questionnaires and checklists from patient files. The results of imaging studies, including magnetic resonance imaging and computed tomography angiography, were also recorded. The obtained data were analyzed by SPSS statistical software.

Results

Among 974 patients suffering from posterior circulation ischemic stroke, 155 patients with an average age of 60.44 ± 13.95 years were included in the study, out of which 97 patients (62.6%) were male. Unilateral vertebral artery hypoplasia on the right, left, and bilateral hypoplasia was present in 67 (43.2%), 35 (22.6%), and 5 (3.2%) patients, respectively. There were complete unilateral fetal origin on the right in 38 (24.5%), complete unilateral on the left in 12 (7.7%), partial unilateral on the right in 12 (7.7%), partial unilateral on the left in 6 (3.9%), complete bilateral in 14 (9%), and partial bilateral in 8 (5.2%) patients. There was no significant relationship between vertebral artery hypoplasia and PCA fetal-type variants with different ischemia locations and infarct patterns (p > 0.05). Also, there was no significant relationship between the age and gender of patients with ischemia location and infarct pattern (p > 0.05).

Conclusion

Despite previous evidence showing a relation between vertebral artery hypoplasia and PCA fetal-type variants as risk factors for PC stroke, the present study did not establish a significant correlation between these factors and the location of ischemia and infarct patterns.

Vertebral artery foraminal segment doppler sonography to detect vertebral and basilar artery stenosis or occlusion

BACKGROUND AND PURPOSE

The diagnostic value of vertebral artery foraminal segment (V2) ultrasonography remains unclear. This study aimed to estimate the predictive value of V2 Doppler imaging for the detection of vertebrobasilar stenosis or occlusion.

METHODS

Three hundred sixty-four vertebral arteries from 182 patients were investigated. Abnormal Doppler spectra were categorized as high-resistance flow (resistive index ≥0.9), low-resistance flow (resistive index ≤0.5), increased flow velocity (peak systolic velocity ≥137.5 cm/second), or no flow signal. On MR angiography, stenosis and occlusion were defined as >50% narrowing and absent flow signals, respectively. The sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) were calculated.

RESULTS

Sixty of 364 vertebral arteries (16.5%) had V2 Doppler abnormalities, while 89 vertebrobasilar arteries (24.5%) had a stenosis or occlusion. The Doppler abnormalities predicted any stenosis or occlusion in the vertebrobasilar artery with a sensitivity of 56.2% and specificity of 96.4% (PPV, 83.3%; NPV, 87.2%). The hypoplastic vertebral artery (lumen diameter ≤2.7 mm) was more frequently associated with vertebrobasilar stenosis or occlusion, and with abnormal Doppler spectra (mostly high-resistance flow), even when it was nonstenotic, than the normal-diameter vertebral artery (p < .001, chi-square test).

CONCLUSIONS

The low sensitivity seems to be due to the high prevalence of non-V2 lesions not detected on V2 Doppler imaging, suggesting the necessity for a more extensive sonographic examination beyond V2. However, PPV and NPV ≥80% may suggest its usefulness in clinical practice.

Association of Left Vertebral Artery Hypoplasia with Posterior Circulation Stroke and the Functional Outcome of Patients with Atrial Fibrillation-Related Cardioembolic Stroke

BACKGROUND AND PURPOSE

A cardiogenic embolus could reach the posterior circulation through the right vertebral artery because of a relatively larger diameter in cases of left vertebral artery hypoplasia. Hence, we investigated whether left vertebral artery hypoplasia is associated with cardiac embolisms with atrial fibrillation in the posterior circulation and its functional outcomes.

MATERIALS AND METHODS

In this monocentric retrospective study, patients with acute cardioembolic stroke with atrial fibrillation were enrolled and underwent CT or neck MRA, which visualized the aortic arch and subclavian arteries. The laterality and size of vertebral artery hypoplasia were recorded. Posterior circulation stroke, basilar artery occlusion, and the functional outcomes after 3 months were investigated.

RESULTS

This study included 407 patients; the patients with left vertebral artery hypoplasia experienced a higher rate of posterior circulation stroke (19 versus 73; 42.2% versus 20.2%; P = .001) and basilar artery occlusion (5 versus 10; 11.1% versus 2.8%; P = .005) than the patients without left vertebral artery hypoplasia. Multivariate analysis revealed that left vertebral artery hypoplasia showed an association with lower odds of achieving a good functional outcome 3 months after the stroke (OR = 0.4; 95% CI, 0.2-0.9; P = .027).

CONCLUSIONS

Patients with cardioembolic stroke and left vertebral artery hypoplasia had posterior circulation stroke, basilar artery occlusion, and poor functional outcomes after 3 months.

Association of Vertebral Artery Hypoplasia and Vertebrobasilar Cerebrovascular Accident

Background and Objectives: Vertebral artery hypoplasia (VAH) is a controversial risk factor for cerebral infarction. The aim of this study was to analyze the prevalence of vertebral artery hypoplasia and to evaluate its association with vertebrobasilar cerebrovascular accidents. Materials and Methods: The study was conducted in the Neurology Departments of the Republican Vilnius University Hospital from 2015 to 2020. Data of 742 subjects (133 patients with posterior circulation infarction or vertebral artery syndrome (PCI/VAS), 80 patients with anterior circulation infarction (ACI) and 529 control subjects with no symptoms of cerebrovascular accident) were analyzed. Ultrasound examination of the extracranial internal carotid and vertebral arteries (VA) was performed, risk factors were recorded. Results: The mean age of the subjects was 64.51 ± 13.02 years. In subjects with PCI/VAS the diameter of VA was smaller, and the prevalence of VAH was higher compared to those in subjects with ACI and in the control group. A higher degree of VAH in subjects younger than 65 years of age increased the risk of PCI/VAS. Subjects with non-dominant VA diameter of 2.7–2.9 mm had 2.21 times higher risk of PCI/VAS, subjects with non-dominant VA diameter of 2.5–2.6 mm had 2.36 times higher risk of PCI/VAS, and subjects with non-dominant VA diameter of 2.2–2.4 mm had 4.12 times higher risk of PCI/VAS compared with subjects with non-dominant VA diameter of ≥3 mm. Among patients with PCI/VAS those with VAH had lower rates of ischemic heart disease compared with patients with normal VA diameter. There was no difference in the rates of other risk factors between PCI/VAS patients with and without VAH. Conclusions: Vertebral artery hypoplasia is not a rare finding in individuals without symptoms of cerebrovascular accident, but more frequent in patients with vertebrobasilar cerebral infarction or vertebrobasilar artery syndrome. Vertebral artery hypoplasia can be considered a risk factor for posterior circulation infarction in subjects under 65 years of age.

Vertebral Artery Stenosis: A Narrative Review

Vertebral artery stenosis (VAS) is the cause of approximately 20% of ischemic strokes in the posterior circulation. There are several causes of vertebral artery stenosis, including atherosclerosis, calcification, dissections, fibromuscular dysplasia, giant cell arteritis, neurofibromatosis type 1, and bony compressions. The most common cause of VAS is atherosclerosis which is derived from the macrophage-induced oxidation of low-density lipoproteins (LDLs), alongside the accumulation of cholesterol. Calcification of the vertebral artery occurs when there is excess calcium and phosphate deposition in the vessel. Dissection of the vertebral artery can lead to the formation of a hematoma causing stenosis of the vertebral artery. Fibromuscular dysplasia can result in stenosis due to the deposition of collagen fibers in the tunica media, intima, or adventitia. Giant cell arteritis, an autoimmune disorder, causes inflammation of the internal elastic membrane resulting in eventual stenosis of the artery. Neurofibromatosis type 1, an autosomal dominant disorder, results in the stenosis of the vertebral artery due to the altered function of neurofibromin. Mechanical compression of the vertebral artery by bone can also cause stenosis of the vertebral artery. Digital subtraction angiography (DSA) is considered the current gold standard in diagnosing vertebral artery stenosis; however, its associated morbidity and mortality have led to increased use of non-invasive techniques such as duplex ultrasonography (DUS), computed tomography angiography (CTA), and magnetic resonance angiography (MRA). Currently, asymptomatic and symptomatic vertebral artery stenoses are treated by risk factor modification and medical treatment. However, it is recommended that surgical (endarterectomy, reconstruction, and decompression) and endovascular (balloon coronary, bare-metal, and drug-eluting stents) treatments are also used for symptomatic vertebral artery stenosis.

Clinical Characteristics of Patients with Vertebral Artery Hypoplasia

Vertebral artery hypoplasia (VAH) belongs to the relatively frequent Doppler ultrasonography (US) findings. However, its clinical significance remains controversial. This was a retrospective study analyzing clinical data of patients undergoing US because of cerebrovascular disease in a single academic neurology center. In the dataset of 2500 US examinations, 80 individuals with VAH (VA diameter < 2.0 mm) were identified (3.2% of all patients). Patients with significant vertebral artery asymmetry (SVAA, difference in VA diameters > 1.0 mm) (n = 80) and patients with normal VA diameter (n = 80) were also recruited. Clinical parameters including clinical signs and symptoms, concomitant diseases, imaging findings and the hospitalization outcome were compared between groups. The frequency of vertigo was highest in VAH group. Ischemic lesions of the cerebellum were found in 10% of VAH patients, 16% of SVAA patients and 5% of control subjects. Neurological deficits improved in over 60% of patients in each group, whereas ca. 30% of patients remained in a stable neurological status. The percentage of patients who deteriorated did not exceed 5% in any of the groups. The results of our study support a relatively high frequency of VAH. Our observations suggest coexistence of VAH with a higher frequency of neurological presentations associated with posterior arterial circulation of the central nervous system.