Aneurysms middle cerebral artery

EC-IC arterial bypass involves the use of general anesthesia, open craniotomy, and end-to-side anastomosis of the superficial temporal artery to a branch of the middle cerebral artery (MCA) (Fig. 6.1). Currently, this technique is being used primarily in the setting of intracranial aneurysm therapy, moyamoya disease, and... 

A ruptured middle cerebral artery aneurysm originating from the site of anastomosis 20 years after extracranial-intracranial bypass for moyamoya disease case report. Surgical Neurology 64 261-265... 

Approximately 85% of spontaneous SAHs are caused by ruptured aneurysm 10% are perimesencephalic and the remainder are caused by rare disorders (van Gijn and Rinkel 2001). The pattern of bleeding on CT is a clue to the underlying cause. Blood in the interhemispheric fissure suggests an anterior communicating artery aneurysm and in the sylvian fissure suggests internal carotid artery or middle cerebral artery aneurysm (Fig. 30.1). 

Intracranial aneurysms are not congenital but develop over the course of life. Approximately 10% of aneurysms are familial, and candidate genes identified thus far include those coding for the extracellular matrix. Saccular aneurysms tend to occur at branching points on the circle of Willis and proximal cerebral arteries approximately 40% on the anterior communicating artery complex, 30% on the posterior communicating artery or distal internal carotid artery, 20% on the middle cerebral artery and 10% in the posterior... 

Fig. 30.1. These CT brain scans from a patient with a burst right middle cerebral artery aneurysm (arrow) show widespread subarachnoid blood, and rupture into the right cerebral hemisphere and the ventricular system.

Intracerebral extension of the hemorrhage occurs in at least a third of patients. Patients with a large hematoma and depressed consciousness might require immediate evacuation of the hematoma, preferably preceded by occlusion of the aneurysm (Niemann et al. 2003). Alternatively, extensive craniectomy can be employed to allow expansion of the brain, as for maUgnant middle cerebral artery infarction (Smith et al. 2002). Subdural hematomas are rare but life threatening and should be removed. 

Fig. 4.16 (a) Axial CTA source images demonstrate a right middle cerebral artery saccular aneurysm, (b) Axial and coronal MIP, and volume-rendered image confirm aneurysm at the right middle cerebral artery... 

Lohani, B. (2004) Fusiform middle cerebral artery aneurysm. Journal of Neuroscience, 1,... 

Sensory systems Eyes A 55-year-old woman developed choroidal infarction with permanent visual loss after intracranial irrigation with papaverine 3 ml (30 mg/ml), used to prevent postoperative vasospasm after surgical clipping of a left middle cerebral artery aneurysm [161 ]. 

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. 

Doerfler A, Wanke I, Goericke SL, Wiedemayer H, Engelhorn T, Gizewski ER, Stolke D, Forsting M (2006) Endovascular treatment of middle cerebral artery aneurysms with electrolytically detachable coils. AJNR Am J Neuroradiol... 

Regli L, Uske A, de Tribolet N (1999) Endovascular coil placement compared with surgical clipping for the treatment of unruptured middle cerebral artery aneurysms a consecutive series. J Neurosurg 90 1025-1030... 

Vanzin JR, Mounayer C, Piotin M, Spelle L, Boissonnet H, Moret J (2005) Endovascular treatment of unruptured middle cerebral artery aneurysms [Article in French]. J Neuroradiol 32(2) 97-108... 

Fig. 40.13. Contrast-enhanced FD-CT with imeron administered intravenously. Transversal MIP, oblique MIP shows a rightsided small M2/M3 middle cerebral artery aneurysm, 1.5 mm in diameter (circle)...

Haematologic Intravenous administration of recombinant tissue plasminogen activator (rtPA), also known as alteplase, is a common component of ischaemic stroke management, but its use is associated with intracranial haemorrhage in 6.4% of patients. A 51-year-old woman who had received IV rtPA for acute left middle cerebral artery thromboembolism later presented with subarachnoid haemorrhage from an acutely ruptured anterior communicating artery aneurysm. The patient xmderwent mechanical thromboembolectomy of the left middle cerebral artery occlusion with recanalization followed by coil embolization of the aneurysm, but she did not improve neurologjcally and ultimately died (32). ... 

Rammos SK, Neils DM, Fraser K, Klopfenstein JD. Anterior communicating artery aneurysm rupture after intravenous thrombolysis for acute middle cerebral artery thromboembolism case report. Neurosurgery June 2012 70(6) 1603-7. 

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