Variations Of Vertebral Artery Research Articles

Concomitant Dual Origin and Fenestration of the Left Vertebral Artery Resembling Dissection

Dual origin and fenestration of the vertebral artery (VA) are very rare anomalies. Understanding of these variations, however, is important because they can be misdiagnosed as a VA dissection. A 42-year-old woman presented with motor weakness and sensory disturbance of the right upper extremity. Radiologic evaluations showed ectatic change in the right VA and an arteriovenous fistula between the right VA and the vertebral vein. We decided on endovascular occlusion of the proximal right VA and its fistulous portion. During the endovascular procedure, we had misunderstood the dual origin and fenestration of the VA as a dissection. Thus, failure to recognize these anomalies might result in unnecessary anticoagulation or therapeutic intervention. Clinicians should be alert to such VA variations when making a diagnosis and when planning any intervention or surgery involving the proximal VA.

Bilateral variations of the vertebral arteries: The left originating from the aortic arch and the left and right entering the C5 transverse foramina

During the dissection course for second year medical students at the University of Toyama in 2005, we encountered variations of the bilateral vertebral arteries: the left directly came off from the aortic arch as the third branch between the left common carotid artery and the left subclavian artery and entered the transverse foramen of C5, instead of C6, whereas the right originated from the right subclavian artery and entered the transverse foramen of C5. The present vertebral artery of each side was possibly formed by the 6th cervical intersegmental artery linked with the longitudinal anastomoses between the cervical intersegmental arteries. Detailed knowledge of vertebral artery variations is crucially important for surgical treatment of blood vessels in the brain, neck and chest.

Normal variation of vertebral artery on CT angiography and its implications for diagnosis of acquired pathology.

CT angiography (CTA) is rapidly becoming a popular tool for the evaluation of cerebrovascular diseases. Noninvasive diagnosis of vertebral artery pathology using CTA relies in part on diminished vertebral artery size or eccentric position relative to the transverse foramen. However, normal variation of the vertebral artery on CT has not been systematically described. Patients younger than 40 years who underwent CTA for reasons other than evaluation of vertebral artery disease were studied. Area measurements of the vertebral artery and the transverse foramen were performed by three radiologists. Variance component analysis was performed. There is marked variation in the size of the vertebral artery relative to the transverse foramen, with the vertebral artery occupying 8-85% of the foramen. In many patients, marked asymmetry in relative vertebral artery size and position was observed. This asymmetry would often vary markedly from level to level within the same patient. Vertebral artery size and position in the transverse foramina vary markedly in normal young subjects. These normal variations must be considered when evaluating vertebral artery pathology on CT angiograms.

Anatomical variations of the vertebral artery in a Zambian indigenous adult population undergoing computerised tomography angiography at the university teaching hospitals Lusaka, Zambia

Vertebral artery is an important source of blood supply to the brain which arises from the subclavian arteries. Anatomical variations have been incidentally reported during autopsy and angiograms. These variations predispose to development of aneurysms, dissections and may lead to vertebrobasilar ischaemia and posterior circulation stroke. Knowledge of variations of the great vessels of the neck is important for endovascular interventionists and diagnostic radiologists, more so in the era of new therapeutic options for intracranial interventions. Forty-two computerised tomography angiograms at the University Teaching Hospitals, Radiology Department Lusaka were examined to investigate vertebral artery variations in a Zambian population and determine the origin of the vessels. These paired vessels were examined thoroughly individually. Eighty-four arteries were examined eighty one (96.4%) had origin from the subclavian artery while three (3.6%) left took origin from the aortic arch. Variations found were two (2.4%) right vertebral arteries had fenestrations, ten (11.9%) had dual origin and one (1.2%) left was hypoplastic. The age ranged from 18 and 81 with mean age of (42.5±) of these seven females and four males had variations. Demographic characteristic (gender and age) had no statistically significant association to variations of vertebral artery (P>0.05). Variations of the vertebral artery are common. Knowledge of these variations is important and helpful in preventing iatrogenic injuries and haemorrhage during endovascular intervention and diagnostic procedures.Keywords: Vertebral artery, duplication, fenestrations, hypoplasia