The five-vessel arch: independent origin of both vertebral arteries from the aortic arch

An independent origin of the left vertebral artery from the aortic arch is the second most common aortic arch anomaly and occurs in 7% of otherwise healthy persons. Bilateral and independent origins of vertebral arteries are distinctly unusual. We present and illustrate such a case.     

Bilateral type 1 proatlantal arteries with absence of vertebral arteries

The persistent proatlantal artery is a well-described communication between the carotid and vertebrobasilar system. However, persistence of bilateral proatlantal arteries is exceptionally rare. Although usually noted as an incidental finding, the presence of a proatlantal artery, particularly when bilateral, may result in unusual symptoms or may have implications for therapy. We report a case of bilateral proatlantal arteries, describe their embryology, and consider potential clinical implications of this finding.     

Aortic arch variation: a unique case with anomalous origin of both vertebral arteries as additional branches of the aortic arch distal to left subclavian artery

We present the case of bilateral anomalous origin of both vertebral arteries (VAs) in a 20-year-old male patient who presented for routine contrast-enhanced CT follow-up examination of the chest. Contrast-enhanced CT revealed abnormal origins of both the VAs from the aortic arch distal to the origin of the left subclavian artery. Following this, CT angiography was performed, which confirmed the findings. To our knowledge, this is the first report of anomalous origins of both VAs beyond the origin of the left subclavian artery. The possible embryonic mechanism and the clinical importance of this variant is also reviewed.     

Duplicated origin of right vertebral artery with rudimentary and accessory left vertebral arteries

Summary We observed a rare cerebrovascular anomaly in a patient with brain-stem infarction. Two right vertebral arteries arose from the subclavian artery and communicated directly with each other under the transverse foramen of the fourth cervical vertebra. The left vertebral artery consisted of a rudimentary artery that arose from the left subclavian artery, ran through the transverse foramen of the sixth cervical vertebra and then tapered down to disappear at the fourth/fifth cervical vertebrae, plus a second, accessory artery that arose from a branch of the left thyrocervical trunk, ran through the transverse foramen of the fifth cervical vertebra and tapered off to disappear at the first/second cervical vertebrae.     

Related anomalies of origin of left vertebral and left inferior thyroid arteries

Summary The known rare occurrence of related anomalies of origin of vertebral and inferior thyroid arteries appears not to be documented in the angiographic literature. Three cases with manifestation on the left side are presented. Embryology is discussed briefly. Knowledge of such anomalies is of importance to surgeons as well as angiographers.     

Bilateral segmental regression of the carotid and vertebral arteries with rete compensation in a Western patient

We report a case of symptomatic symmetrical, bilateral absence of the cavernous internal carotid (ICA) and transdural vertebral artery (VA) segments with formation of a rete mirabile. There have been similar reports in Asian patients; ours is the first in the Western population. A 29- year-old woman presented with recurrent temporary blindness and an episode of minor subarachnoid haemorrhage. Angiography demonstrated absence of the C5 and C6 segments of the ICA and the C1/2 segments of the VA bilaterally, with typical carotid rete mirabile formation to reconstitute the distal flow. Comparative anatomy and embryology show retia in several species and point to their secondary origin. The anomalies of the ICA cannot be called agenesis but rather absence since they are likely to result from perinatal disappearance of the artery rather its failure to develop.     

Bifid direct aortic arch origin of left vertebral artery: a unique vascular variant

The present report describes an unusual case of a duplicated origin of the left vertebral artery from the aorta discovered incidentally in a young patient. Computed tomographic angiography followed by conventional angiography demonstrated this anomaly. Angiographic findings and vertebral artery embryogenesis and anomalies are discussed.     

Injury of the carotid and vertebral arteries

Summary A knowledge of the normal anatomy and anatomic relationships of the carotid and vertebral arteries, as well as the biomechanics by which traumatic injury occurs to these vessels, is important both in the interpretation of diagnostic arteriograms and in the clinical assessment of the injured patient.     

Color-coded Doppler sonography of the vertebral arteries

Color-coded Doppler sonography of the vertebral arteries was performed in 86 patients with a history of vertebrobasilar disease. The origin of the artery was visualized in 87.2% on the right and 70.9% on the left side. The interforamen portion of the vertebral artery was visualized in 95% on the right and 97% on the left side. The atlas loop could be visualized in 88.4% on the right and 84.9% on the left side. Pathologic findings were hypoplasia (n = 4), stenosis (n = 19), dissection (n = 2), occlusion (n = 7), kinking (n = 12), and subclavian steal syndrome (n = 3). Nine postoperative patients had subclavian and vertebral artery reimplantation into the common carotid artery. The characteristic color-coded Doppler sonographic features of these findings are presented and discussed.     

Posttraumatic occlusion of the 2 vertebral arteries

Initial radioclinical examination of a 24 year old patient following a road accident showed a hemomediastinum on computed tomography imaging. Digital subtraction angiography by the arterial route demonstrated integrity of abdominal aorta and occlusion of both vertebral arteries soon after their origin. This bilateral occlusion had failed to provoke any neurologic sign imputable to the vascular lesion. A review venous digital subtraction angiography examination two months later gave similar angiographic appearance. Emphasis is placed on the asymptomatic nature of this acute occlusion of the two vertebral arteries and on the value of digital subtraction angiography for vascular exploration of this type of disease.     

Bilateral aberrant internal carotid arteries

An aberrant course of the internal carotid artery is a rare vascular anomaly. This is the only known reported case of bilateral aberrant internal carotid arteries examined with CT and MRI.     

Persistence of both proatlantal arteries with absence of vertebral arteries

Summary A case of bilateral persistence of the proatlantal arteries with absence of both vertebral arteries proved by angiography is reported.     

Bifid origin of the left vertebral artery

Two patients demonstrating a bifid origin of the left vertebral artery are described. The embryologic origin of this anomaly is reviewed together with diagnostic and therapeutic implications, emphasizing the importance of knowledge and recognition of the anomaly. It is suggested that this anomaly is not as rare as previously thought.     

Bilateral aneurysms of the cervical internal carotid arteries

Summary An unusual case of bilateral aneurysms of the internal cervical carotid arteries in a 38 year old man with right hemiplegia and aphasia is described.     

Bilateral occlusion of the cervical internal carotid arteries

Summary The case of a man, aged 67, who had bilateral occlusion of the cervical internal carotid arteries with an unusual collateral circulation between the occipital artery and the anterior cerebral artery, is described.     

Identification of vertebral arteries on CT of the chest

Knowledge of the superior mediastinal course of the vertebral arteries is important for radiologists who evaluate chest CT, particularly in the setting of trauma, when planning a percutaneous interventional procedure or for pre-operative planning. Our aim was to determine how often the vertebral arteries could be identified on chest CT studies. Contrast enhanced chest CT studies from 100 consecutive patients were reviewed, with specific attention to the vertebral arteries in the superior mediastinal and thoracic outlet regions. The left vertebral artery was identified in 85 patients and the right vertebral artery in 76 patients. Non-visualization of a vertebral artery was usually owing to proximal venous occlusion with extensive collateral vessels in the expected location of the vertebral arteries, local lymphadenopathy, poor contrast bolus technique or local beam hardening artefact. Radiologists need to alert surgeons planning resection of mass lesions in this region to the location of the vertebral arteries. It is also important to note that a vertebral artery was not identified on chest CT in 24% of patients.