Intracranial vertebral aneurysms

Albuquerque PC, Fiorella DJ, Han PP, Deshmukh VR, Kim LJ, McDougall CG (2005) Endovascular management of intracranial vertebral artery dissecting aneurysms. Neu-rosurg Focus 18(2) E3... 

Embolism from thrombus within the cavity of an aneurysm is rare and is difficult to prove in cases where there maybe other potential sources of embolization. Intracranial aneurysms more commonly present with rupture and subarachnoid hemorrhage, whereas internal carotid artery aneurysms tend to cause pressure symptoms including a pulsatile and sometimes painful mass in the neck or pharynx, ipsilateral Horner s syndrome or compression of the lower cranial nerves. Extracranial vertebral artery aneurysms may cause pain in the neck and arm, a mass, spinal cord compression and upper limb ischemia (Catala et al. 1993). 

A systematic review of all prospective studies of the risks associated with spinal manipulation included five primary investigations (150). The most valid studies suggested that about half of all patients who see a chiropractor will have adverse effects, which are usually mild and transient. No reliable data about serious adverse events were uncovered. However, a review of recent case reports has shown that spinal manipulation was associated with several serious adverse effects, including dissection of the vertebral and internal carotid arteries, resulting in strokes and at least one death (151). Other instances relate to epidural hematoma, intracranial aneurysm, cauda equina syndrome, contusion of the spinal cord, myelopathy, radiculopathy, and palsy of the long thoracic nerve. 

Suxamethonium-induced fasciculation or increased muscle tone can be dangerous in patients with fractures or dislocations (especially vertebral, when the drug is relatively contraindicated), in patients with open-eye injuries or after the eyeball is opened surgically, when an increase in abdominal pressure must be avoided (pheochromocytoma, aortic aneurysm, full stomach, ileus), and in patients in whom a rise in arterial pressure may be catastrophic (cerebral aneurysm, raised intracranial pressure). Prolonged paralysis, occasionally lasting hours, is a risk if the patient is, or has been, taking certain drugs. 

Most arterial aneurysms arise at the bifurcation of major arteries, and this is also true for the intracranial location. Around 85% of all intracranial aneurysms originate from the anterior circulation. The most common location (30%-35%) is the anterior communicating artery (Acorn). However, many of these so-called Acorn aneurysms do have their origin at the A1/A2 junction of the anterior cerebral artery and do not involve the anterior communicating artery. Internal carotid and posterior communicating artery aneurysms account for 30% and middle cerebral artery (MCA) bifurcation aneurysms for 20%. Around 15% of intracranial aneurysms arise at the vertebrobasilar circulation. Half of them develop at the basilar tip (with various degrees of involvement of the PI segments) and the other 50% from other posterior fossa vessels. Aneurysms of the anterior inferior cerebellar artery (AICA) and vertebral artery (VA) aneurysms without involvement of the VA-PICA junction or the vertebrobasilar site are extremely rare. 

Various nondetachable balloons are available for temporary vessel occlusion, angioplasty for vasospasm therapy or remodelling techniques for broad based aneurysms. Larger vessels like the carotid or vertebral artery can be occluded with a double lumen balloon catheter, i.e. Meditech (Cook). For intracranial angioplasty and remodeling smaller, more flexible balloons, like the Hyperglide (MTI), Eclipse (Balt), or the Copernic (Balt) are required. Additionally to these balloons tbe Hyperform microballoon (MTI) can be used for remodelling technique. 

Lanzino G, Wakhloo AK, Fessler RD, Hartney ML, Guter-man LR, Hopkins LN (1999b) Efficacy and current limitations of intravascular stents for intracranial internal carotid, vertebral, and basilar artery aneurysms. J Neurosurg 91 538-546... 

Neurosurgery 40 651-662 discussion 662-663 Schievink WI (2001) Spontaneous dissection of the carotid and vertebral arteries. N Engl J Med 344 898-906 Schievink WI, Wijdicks EF, Piepgras DG, Chu CP, O Fallon WM, Whisnant JP (1995) The poor prognosis of ruptured intracranial aneurysms of the posterior circulation. J Neurosurg 82 791-795... 

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