Internal artery

Lipid removal may be a critical factor in plaque formation and the location of lecithin-cholesterol trans-acylase in the arterial wall could play an important role since cholesterol is rapidly exchanged" with the blood while cholesterol ester is not. Kuo in an editorial cites the evidence for the theory that a dlsturbemce in carbohydrate metabolism can be responsible for atherosclerosis and should be included as one of the primary risk factors in coronary heart disease. In this regard, Clements and coworkers have shown the presence in aorta of aldose reductase, an enzyme which they feel provides a mechanism for the alteration of arterial metabolism by hyperglycemia. Another approach to molecular interactions was described by Levy and Day who concluded from their results that the low density lipoproteins are uniquely polycationic at the surface and that these ions react with the internal arterial macromolecular polyanions. 

In addition to its internal blood flow operation, the heart has its own system of blood vessels to keep the muscle wall of the heart, the myocardium, supphed with oxygenated blood (Fig. 3a). The coronary arteries, which branch from the aorta to the right and left sides of the heart, are vital to maintaining that supply. The heart is an extraordinary electromechanical muscle that can be trained to increase blood flow to the body sixfold. It can range from 5 to 30 L /min during exertion. 

Intraarterial infusion of microspheres containing adriamycin was used for the local treatment of breast cancer and recurrent breast cancer with liver metastases (123). A reduction in tumor size was noted when the microspheres were injected into the internal and lateral thoracic arteries for treatment of the primary tumor. However, hepatic artery injection for liver metastases resulted in improvement in only one of three patients treated. 

The first elastomeric protein is elastin, this structural protein is one of the main components of the extracellular matrix, which provides stmctural integrity to the tissues and organs of the body. This highly crosslinked and therefore insoluble protein is the essential element of elastic fibers, which induce elasticity to tissue of lung, skin, and arteries. In these fibers, elastin forms the internal core, which is interspersed with microfibrils [1,2]. Not only this biopolymer but also its precursor material, tropoelastin, have inspired materials scientists for many years. The most interesting characteristic of the precursor is its ability to self-assemble under physiological conditions, thereby demonstrating a lower critical solution temperature (LCST) behavior. This specific property has led to the development of a new class of synthetic polypeptides that mimic elastin in its composition and are therefore also known as elastin-like polypeptides (ELPs). 

Phillips DA, Davis MA, Fisher M. Selective embolization and clot dissolution with tPA in the internal carotid artery circulation of the rabbit. AJNR Am J Neuroradiol. 1988 9 899-902. 

Internal Carotid Artery Occlusion Acute stroke due to a distal ICA T (T = terminus) occlusion carry a much worse prognosis than MCA occlusions. In a recent analysis of 24 consecutive patients (median NIHSS 19) presenting with T occlusions of the ICA who were treated by lAT using urokinase at an average of 237 minutes from symptom onset, only four patients (16.6%) had a favorable outcome at 3 months. Partial recanalization of the intracranial ICA was achieved in 15 (63%), of the MCA in 4 (17%), and of the ACA in 8 patients (33%). Complete recanalization did not occur. The presence of good leptomeningeal collaterals and age <60 years were the only predictors of a favorable clinical outcome. New treatment strategies, such as the combination of IV rt-PA and lAT, or the use of new mechanical devices may improve the outcome in these patients. 

A significant neurologic deficit expected to result in long-term disability, and attributable to large vessel occlusion (basilar, vertebral, internal carotid, or middle cerebral artery M1 or M2 branches). 

Arnold M, Nedeltchev K, Mattie HP, Loher TJ, Stepper F, Schroth G, Brekenfeld C, Sturzenegger M, Remonda L. Intra-arterial thrombolysis in 24 consecutive patients with internal carotid artery T occlusions. J Neurol Neurosurg Psychiatry 2003 74 739-742. 

Zaidat OO, Suarez Jl, Santillan C, Sunshine JL, Tarr RW, Paras VH, Selman WR, Landis DM. Response to intra-arterial and combined intravenous and intra-arterial thrombolytic therapy in patients with distal internal carotid artery occlusion. Stroke 2002 33 1821-1826. 

Khatri P, Broderick J, Khoury JC, Carrozzella J, Tomsick T, for the IMS-1 and 2 Investigators. Microcatheter contrast injections during intra-arterial thrombolysis increase intracranial hemorrhage risk. International Stroke Conference Kissimmee, Elorida 2006. 

Jovin TG, Gupta R, Uchino K, Jungreis CA, Wechsler LR, Hammer MD, Tayal A, Horowitz MB. Emergent stenting of extracranial internal carotid artery occlusion in acute stroke has a high revascularization rate. Stroke 2005 36 2426-2430. 

Bellon RJ, Putman CM, Budzik RF, Pergolizzi RS, Reinking GF, Norbash AM. Rheolytic thrombectomy of the occluded internal carotid artery in the setting of acute ischemic stroke. Am J Neuroradiol 2001 22 526-530. 

CEA involves exposure of the carotid bifurcation in the neck to a point along the internal carotid artery (ICA) beyond which the atherosclerotic plaque terminates. 

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. 

Touho H, Morisako T, Hashimoto Y, Karasawa J. Embolectomy for acute embolic occlusion of the internal carotid artery bifurcation. Surg Neurol 1999 51 313-320. 

Clinical trials and meta-analyses have demonstrated that early carotid endarterectomy (CEA) is the preferred treatment for most patients with severe symptomatic internal carotid artery (ICA) stenosis and selected patients with moderate disease.However, CEA is often delayed in chnical practice, or may not be appropriate in some patients due to an unfavorable risk-benefit profile. In these settings, it is reasonable to consider acute antithrombotic treatment to prevent early recurrent stroke. 

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). ° ... 

Lucas C, Moulin T, Deplanque D, Tatu L, Chavot D. Stroke patterns of internal carotid artery dissection in 40 patients. Stroke 1998 29 2646-2648. 

Engelter S, Lyrer P, Kirsch E, Steck AJ. Long-term follow-up after extracranial internal carotid artery dissection. Eur Neurol 2000 44 199-204. 

Lu CJ, Kao HL, Sun Y, Liu HM, Jeng JS, Yip PK, Lee YT. The haemodynamic effects of internal carotid artery stenting a study with color-coded duplex sonography. Cerebro-vasc Dis 2003 15 264-269. 

Suwanwela N, Can U, Furie KL, Southern JF, Macdonald NR, Ogilvy CS, Hansen CJ, Buonanno FS, Abbott WM, Koroshetz WJ, Kistler JR Carotid Doppler ultrasound criteria for internal carotid artery stenosis based on residual lumen diameter calculated from en bloc carotid endarterectomy specimens. Stroke 1996 27(11) 1965-1969. 

Erickson SJ, Mewissen MW, Foley WD, Lawson TL, Middleton WD, Quiroz FA, Macrander S J, Lipchik EO. Stenosis of the internal carotid artery assessment using color... 

Polak IF, Dobkin GR, O Leary DH, Wang AM, Cutler SS. Internal carotid artery stenosis accuracy and reproducibility of color-Doppler-assisted duplex imaging. Radiology 1989 173(3) 793-798. 

The normal arterial wall consists of the intima, media, and adventitia, as illustrated in Fig. 4—3A. The endothelium is located in the intima and consists of a layer of endothelial cells that line the lumen of the artery and form a selective barrier between the vessel wall and blood contents. The internal elastic lamina separates the intima and media, where vascular smooth muscle cells are found. The vascular adventitia comprises the artery s outer layer. Atherosclerotic lesions form in the subendothelial space between the endothelial cells and internal elastic lamina. 

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