Artery vertebral

The MERCI trial was a prospective single-arm, multicenter trial designed to test the safety and efficacy of the MERCI clot retrieval device to restore the patency of intracranial arteries in the first 8 hours of an acute stroke. All patients were ineligible for IV rt-PA. The occlusion sites were the intracranial vertebral artery, basilar... 

FIGURE 4.5 A 72-year-old man with medical history remarkable for hypertension and dyslipidemia presented with posterior circulation infarct (a). CTA and posterior circulation angiography (left vertebral artery injection) performed demonstrated severe mid-basilar artery stenosis (b and c). Left vertebral artery injection demonstrated near-complete reversal of the stenosis after a drug-eluting balloon expandable stent (Cypher, Cordis Johnson Johnson) was deployed (d). 

Dissection of the internal carotid and vertebral arteries is a common cause of stroke, particularly in young patients. Although many occur due to trauma, it is estimated that over half occur spontaneously. The mechanism of stroke following arterial dissection is either by artery-to-artery embolism, by thrombosis in situ, or by dissection-induced lumenal stenosis with secondary cerebral hypoperfusion and low-flow watershed infarction. Occasionally, dissection may lead to the formation of a pseudoaneurysm as a source of thrombus formation. Vertebrobasilar dissections that extend intracranially have a higher risk of rupture leading to subarachnoid hemorrhage (SAH). ° ... 

Jacobs A, Lanfermann H, Neveling M, Szelies B, Schroder R, Heiss WD. MRI- and MRA-guided therapy of carotid and vertebral artery dissections. J Neurol Sci 1997 147 27-34. 

Schievink W. The treatment of spontaneous carotid and vertebral artery dissections. Curr Opin Cardiol 2000 15 316-321. 

A 64-year-old man with giant cell arteritis was given prednisolone 60 mg/day. Within 5 days he developed double vision and agitation and became drowsy and confused. A cranial MRI scan showed recent cerebral lesions and a Doppler scan showed high-resistant blood flow in both vertebral arteries. He had an episode of complete loss of vision and was given dexamethasone... 

Endovascular versus surgical treatment in patients with carotid stenosis in the Carotid and Vertebral Artery Transluminal Angioplasty Study (CAVATAS) a randomised trial. Lancet 2001 357 1729-1737. 

In severe occlusive disease of the subclavian artery (SCA) blood supply of the arm is mainly provided by reversed flow through the vertebral artery (VA) arising behind the obstruction. The so-called subclavian-steal syndrome consists of ischemic symptoms in the arm, especially after exercise, such as pain or numbness or coolness (Reivich et al. 1961). Consequently a diminished or delayed pulse in the radial artery or decreased blood pressure on the side of SCA stenosis can be palpated. Rarely neurological symptoms such as spells of dizziness may be brought about by exercise ofthe arm. Even more rare are ischemic brainstem strokes in subclavian-steal syndrome (Bornstein and Norris 1986). 

Spontaneous dissection of the internal carotid or the vertebral artery is an important cause of ischemic stroke in young adults (Fig. 1.3). In the late 1970s Fisher et al. (1978) and Mokri et al. (1979) described dissections of carotid and vertebral arteries as detected by modern diagnostic techniques rather than by post-mortem examination. This may occur... 

Fig.5.7a-d. Time resolved sequential MRA. On high resolution CE-MRA (a), the left vertebral and left subclavian arteries are not fully enhanced. Selected images from a time-resolving sequence (b-d) with one frame per second demonstrate top-down contrast filling of the left vertebral artery and delayed enhancement of the left subclavian artery. Note low spatial resolution of sequential images... 

The truncus brachiocephalicus and the left CCA show a combined origin from the aortic arch in approximately 25% of cases. The left vertebral artery rarely arises directly from the arch proximal to the subclavian artery. Infrequently an aberrant right subclavian artery leaves the aorta distal to the left subclavian artery and crosses the mediastinum dorsal to the esophagus and is then called the arte-ria lusoria (Fig. 5.10). Elongations and ectasias of the aortic arch and supraaortal vessels, which can impair the imaging quality of the vessels, are often seen in elderly patients. 

Vertebral arteries vary in size and symmetry, where mostly the left vertebral artery is the dominant one. The coincidence of vertebral fenestrations and aneurysms is well known. The anterior spinal artery receives tiny vessels from the vertebral arteries which are physiologically not depicted by MRA due to their size. The posterior inferior cerebellar artery (PICA) as the largest, most important and most variable cerebellar artery however, under normal conditions it is constantly depictable with TOF and CE-MRA. 

Liu Y, Karonen JO, Vanninen RL et al. (2004) Acute ischemic stroke predictive value of 2D phase-contrast MR angiography-serial study with combined diffusion and perfusion MR imaging. Radiology 231 517-527 Lucas C, Leclerc X, Pruvo JP et al. (2000) [Vertebral artery dissections follow-up with magnetic resonance angiography and injection of gadolinium]. Rev Neurol (Paris) 156 1096-1105... 

Medullary infarcts can be medial, lateral or combined (Fig. 14.6). The medial territory is supplied by penetrating vessels from the anterior spinal artery and the distal vertebral artery. The lateral territory main arterial supply comes from penetrating arteries from the distal vertebral artery and the posterior inferior cerebellar artery. The small posterior territory is supplied by the posterior spinal artery and the posterior inferior cerebellar artery. Medial... 

Q2 The brain forms about 2% of body weight but receives approximately 20% of the cardiac output and approximately 20% of the body s oxygen supply. Blood reaches the brain via two internal carotids and two vertebral arteries the latter fuse inside the cranium to form the basilar artery. The carotid and basilar arteries are interconnected via the Circle of Willis, which forms a ring of blood vessels in the brain. This arrangement ensures that brain tissues can be supplied with blood from either the carotid or vertebral arteries and reduces the chances of an interrupted blood supply. 

The brain uses a substantial proportion of body oxygen and there is a generous blood supply to the brain from the carotid and vertebral arteries. Interruption of brain blood flow for more than a very short time causes neuronal damage and ultimately cell death. Cerebral blood flow is normally controlled by autoregulation. 

Vertebral artery dissection has been described in a previously healthy man with a 3-year history of daily oral amfetamine abuse (26). 

Since this patient had no known risk factors for vertebral artery dissection and had abused amfetamine daily for 3 years with escalating amounts, an association between metamfetamine and vertebral artery dissection cannot be excluded. The local and systemic vascular impacts of amfetamine could have contributed to initial changes (along with smoking), resulting in dissection. 

Zaidat OO, Frank J. Vertebral artery dissection with amphetamine abuse. J Stroke Cerebrovasc Dis 2001 10 27-9. 

A 70-year-old woman with a history of mastectomy developed syncope which lasted a few seconds. She had taken tamoxifen 10 mg bd for 10 years and had no history of allergic reactions. Doppler ultrasound showed aortic stenosis and coronary angiography was performed using 150 ml of iopromide (a non-ionic contrast medium, iodine 370 mg/ml). She had visual hallucinations (spiders on the wall, moving curtains) 30 minutes after the injection of iopromide. The symptoms resolved 72 hours later without any specific treatment. Neurological and psychiatric examinations were normal, as were brain MRI and Doppler ultrasound of the carotid and vertebral arteries. 

The brain makes up only 2% of the total body weight, but when the body is at rest, it receives 20% of the cardiac output and consumes about 20% of the total inspired oxygen. The anterior two-thirds of the brain is supplied by the two internal carotid arteries, and the posterior third of the brain by the two vertebral arteries (Fig. 4.1). These four arteries anastomose at the base of the brain to form the circle of Willis (Fig. 4.2). 

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