Intracranial arterial

With modern multislice scanners and optimized protocols," CTA images can provide excellent visualization of the primary intracranial arteries (i.e., the proximal anterior, middle, and posterior cerebral arteries), their smaller secondary... 

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... 

Ueda T, Sakaki S, Nochide I, Kumon Y, Kohno K, Ohta S. Angioplasty after intra-arterial thrombolysis for acute occlusion of intracranial arteries. Stroke 1998 29 2568-2574. 

Hans Henkes JR, Lowens S, Miloslavski E, Roth C, Reith W, Kiihne D. A device for fast mechanical clot retrieval from intracranial arteries (Phenox Clot Retriever). Neurocrit Care 2006 5 134-140. 

Veznedaroglu E, Levy El. Endovascular management of acute symptomatic intracranial arterial occlusion. Neurosurgery 2006 59 S242-S250. 

Engel S, Ferraz H. Indications and results of extra-intracranial arterial bypasses. Int Surg 1983 68 197-200. 

Failure of extracranial-intracranial arterial bypass to reduce the risk of ischemic stroke. Results of an international randomized trial. The EC/IC Bypass Study Group. N Engl J Med 1985 313 1191-1200. 

Fig.5.1. Typical TOF-MRA (three overlapping slabs) of basal intracranial arteries. Maximum intensity projection. Slightly bright signal from fat tissue (orbits, skin)...

Atherosclerosis mainly affects large- and mediumsized arteries. Extracranial manifestations at the carotid bifurcation statistically dominate the intracranial arteries. Besides typical manifestations at the carotid siphon or the vertebrobasilar junction, atherosclerosis is occasionally also found in peripheral intracranial vessel segments. Typical sequelae of atherosclerosis are stenosing plaque formations, ulcerations, dilatations or the evolution of fusiform aneurysms, which can be accompanied by extensive formation of thrombus. 

The depiction of intracranial arterial stenosis by MRA requires a high sensitivity resolution technique, while the importance of an exact grading by MRA is not defined yet. A preventive anti-calculation for stenosis of proximal intracranial segments exceeding 50% is still a matter of debate (Sherman 2002). 

Japanese and Chinese populations. Stroke, particularly primary intracerebral hemorrhage, is more common in Japan and China than in Western countries (Huang et al. 1990) and this is accompanied by less extracranial but more intracranial arterial disease (Feldmann et al. 1990 Leung et al. 1993 Sacco et al. 1995 Wityk et al. 1996). 

Aaslid R, Lindegaard KF, Sorteberg W et al. (1989). Cerebral autoregulation dynamics in humans. Stroke 20 45-52 Adams HP Jr., Powers WJ, Grubb RL Jr., (2001). Preview of a new trial of extracranial-to-intracranial arterial anastomosis the carotid occlusion surgery study. Neurosurgery Clinics of America 12 613... 

Table 6.4. Causes of disseaion of the extra- and intracranial arteries...

Extracranial to intracranial arterial bypass surgery in stroke prevention... 

Chimowitz MI, Lynn MJ, Howlett-Smith H et al. (2005). Comparison of warfarin and aspirin for symptomatic intracranial arterial stenosis. New England Journal of Medicine 352 1305-1316... 

The study of cerebrovascular disease has advanced markedly in recent years with advances in non-invasive imaging methods such as MR angiography and CT angiography as well as an improved understanding of the immune system in the pathogenesis of atherosclerosis. Atherosclerotic cerebrovascular disease is a common cause of strokes and shows a predilection for sites such as the bifurcation of the common carotid artery into the internal and external carotid arteries and the aortic arch and the major intracranial arteries such as the basilar artery and the middle cerebral arteries. Occlusive atherosclerotic vascular disease of these large extracranial arteries is responsible for as many as 20-30% of ischemic strokes and intracranial steno-occlusive disease causes around 5-10% of ischemic strokes. 

Inhibition of plasminogen by tranexamic acid and aminocaproic acid conld theoretically facilitate the development of thrombosis, bnt whether it actnally does so has been the snbject of contradictory reports. Episodes of venous and arterial thrombosis have been reported in association with treatment using either tranexamic acid or aminocaproic acid. These include thrombosis at unusual sites such as mesenteric thrombosis (46), aorta (47), retinal artery occlusion (48), and intracranial arterial thrombosis (49-51), as well as deep vein thrombosis in the legs (52). 

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