Atherosclerotic stenosis

Studer A, Georgiadis D, Baumgartner RW (2003) Ischemic infarct involving all arterial territories of the thalamus. Acta Neurol Scand 107 423-425 Timsit SG, Sacco RL, Mohr JP et al (1992) Early clinical differentiation of cerebral infarction from severe atherosclerotic stenosis and cardioembolism. Stroke 23 486-491 Tong DC, Adami A, Moseley ME et al (2000) Relationship between apparent diffusion coefficient and subsequent hemorrhagic transformation following acute ischemic stroke. Stroke 31 2378-2384... 

Additional common sites for atherosclerotic occlusion include the origin of the vertebral artery, the distal vertebral and vertebrobasilar junction, the midbasilar artery, and the proximal PCA. Unlike ICA disease, severe atherosclerotic stenosis in the distal intracranial vertebral and basilar arteries can cause stroke via thrombotic occlusion of local branches as well as artery-to-artery embolus to the top of the basilar artery or the PCA(s). Low flow in the basilar artery can lead to thrombus formation with occlusion of one brainstem penetrator vessel after another. Basilar thrombosis is not rare and is fatal because brainstem function is completely dependent on this vascular supply [20, 23]. 

Stents are cylindrically shaped devices, which function to hold open and sometimes expand a segment of a blood vessel or other anatomical lumen such as urinary tracts and bile ducts (66). Stents are often used in the treatment of atherosclerotic stenosis in blood vessels. 

Renal arteries are more commonly investigated by MRI rather than by CT. However, CTA in combination with oblique MIP or VRT is helpful in the detection of different pathologies of the renal arteries, such as atherosclerotic stenosis, fibromuscular dysplasia or Takayasu arteritis. Post-processing of the renal arteries also allows measurement of the degree of stenosis prior to intervention, or as followup control (Sabharwal et al. 2006). 

Anatomic Consideration The internal iliac arteries, the blood supply to the viscera of the true pelvis, are readily approached after femoral arterial access. The ipsilateral internal iliac artery is usually catheterized with a reverse curve catheter configuration and the contralateral internal iliac artery is usually accessed following passage over the aortic bifurcation with a forward seeking cobra catheter. On rare occasions because of atherosclerotic stenosis or occlusion of one femoral artery, two catheters (4-5 F) can be... 

The relationship between LAA and early recurrence is likely to be largely mediated by arterial embolism from atherosclerotic plaque, although recurrent low-flow stroke may also occur due to severe vessel stenosis or occlusion. In recently symptomatic individuals with moderate-or-severe ICA stenosis, platelet-fibrin embolic signals (ES) are commonly detected in the MCA using transcranial Doppler (TCD) ultrasound and have been reported to independently predict a fivefold increase in 90-day recurrence. " ... 

Endothelial dysfunction, inflammation, and the formation of fatty streaks contribute to the formation of atherosclerotic coronary artery plaques, the underlying cause of coronary artery disease (CAD). The predominant cause of ACS, in more than 90% of patients, is atheromatous plaque rupture, Assuring, or erosion of an unstable atherosclerotic plaque that occludes less than 50% of the coronary lumen prior to the event, rather than a more stable 70% to 90% stenosis of the coronary artery.3 Stable stenoses are characteristic of stable angina. 

Percutaneous coronary intervention A minimally invasive procedure whereby access to the coronary arteries is obtained through the femoral artery up the aorta to the coronary os. Contrast media is used to visualize the coronary artery stenosis using a coronary angiogram. A guidewire is used to cross the stenosis and a small balloon is inflated and/or stent is deployed to break up atherosclerotic plaque and restore coronary artery blood flow. The stent is left in place to prevent acute closure and restenosis of the coronary artery. Newer stents are coated with antiproliferative drugs, such as paclitaxel and sirolimus, which further reduce the risk of restenosis of the coronary artery. 

In Apo E-deficient animals fed a normal chow diet, fatty streaks are first observed in the proximal aorta at 10 to 12 weeks (15). The xanthoma that forms in the intima contains foam cells and is often called the early atherosclerotic lesion and is critically dependent on monocytes. Smooth muscle cells (SMCs) arrive in the intima at approximately 15 weeks and form a fibrous cap around 20 weeks (16). By 36 weeks, lumen narrowing occurs in the external branches of the carotid artery (incidence -75%), but the lumen size is maintained in the aorta. Lumen narrowing, or stenosis, does not correlate with plaque size but... 

Growing clinical data also points to the importance of IL-8 in atherogenesis. IL-8 has been found in atheromatous lesions from patients with atherosclerotic disease including carotid artery stenosis (103), CAD (118), abdominal aortic aneurysms (AAA) (103,104,114), and peripheral vascular disease (PVD) (104). Furthermore, studies using plaque explant samples have yielded more direct evidence for IL-8 involvement. Media from cultured AAA tissue induced IL-8-dependent human aortic endothelial cell (HAEC) chemotaxis (122). Homocysteine, implicated as a possible biomarker for CAD, is also capable of inducing IL-8 (123-125) by direct stimulation of endothelial cells (123,124) and monocytes (125). When patients with hyperhomocysteinemia were treated with low-dose folic acid, decreases in homocysteine levels correlated with decreases in IL-8 levels (126). Statins significantly decrease serum levels of IL-6, IL-8, and MCP-1, as well as expression of IL-6, IL-8, and MCP-1 mRNA by peripheral blood monocytes and HUVECs (127). Thus, IL-8 may be an underappreciated factor in the pathogenesis of atherosclerosis. 

Atherosclerotic lesions occluding Rj increase arteriolar resistance, and R2 can vasodilate to maintain coronary blood flow. With greater degrees of obstruction, this response is inadequate, and the coronary flow reserve afforded by R2 vasodilation is insufficient to meet oxygen demand. Relatively severe stenosis (greater than 70%) may provoke ischemia and symptoms at rest, whereas less severe stenosis may allow a reserve of coronary blood flow for exertion. 

Demrow et al. (1995) used the Folts model of unstable coronary stenosis, which closely mimics ruptured atherosclerotic plaque, causing unstable angina, to examine the effects of grape juice on platelet function in vivo. In this model,... 

Most ischemic strokes are due to atherosclerotic cerebrovascular disease. Patients with symptomatic carotid stenosis of > 70% should be considered for endarterectomy. Aspirin is used for prophylaxis following transient ischemic attacks and minor stroke. 

Atherosclerotic occlusion or stenosis of the pudendal or cavernosa arteries Arterial damage from pelvic radiation Venous leak... 

Figure 8.1 Therapeutic effect of pomegranate juice on atherosclerotic lesion area in E° mice (A-C) or in patients with carotid artery stenosis (D and E). Thirty E° mice and 10 patients with severe CAS were supplemented with PJ concentrate (12.5 pL/mouse/day and 50 mL/day, respectively) for 9 weeks or for 1 year, respectively. Photomicrographs of typical foam cells from unsupplemented 4-month-old E° mice and from 6-month-old E° mice administered a placebo (B) or PJ (C) are presented. Mean ( SEM) effect of PJ consumption on human common carotid artery IMT (D) and end diastolic velocity (EDV) (E) are shown. = p < 0.01 (after vs. before PJ consumption).

All these antioxidative and anti-atherogenic effects of pomegranate polyphenols were clearly demonstrated in vitro, as well as in vivo in humans, and in the atherosclerotic apolipoprotein E-deficient mice. Dietary supplementation of pomegranate juice rich in polyphenols to patients with severe carotid artery stenosis or to atherosclerotic mice resulted in a significant inhibition in the development of the... 

Even with selective catheter angiography, there can be difficulty in distinguishing occlusion from extreme internal carotid artery stenosis, and then late views are needed to see contrast eventually passing up into the head. Moreover, because of the localized and non-concentric nature of atherosclerotic plaques, biplanar, and preferably triplanar (Jeans et al. 1986 Cuffe and Rothwell 2006), views of the carotid bifurcation are required to measure the degree of carotid stenosis accurately that is, to visualize the residual lumen without overlap of other vessels, to measure at the narrowest point and to compare with a suitable denominator to derive the percentage diameter stenosis. 

Many investigators identified smoking as a strong risk factor for atherosclerotic renal artery stenosis Hadj-Abdelkader [21] found that 70-80% of patients with this diagnosis were smokers and frequently these stenoses are bilateral [22] and frequently the source of cholesterol microembolism [23]. 

Platelet aggregation plays an important role in the pathogenesis of acute coronary syndromes (ACS). Myocardial infarction is an ACS that occurs when atherosclerotic plaques embedded in artery walls rupture, leading to thrombus formation and coronary occlusion. Patients with high-risk coronary stenosis may need percutaneous coronary interventions (PCI) with or without stent placement to revascularize the arteries. 

E. Falk, Plaque rupture with severe pre-existing stenosis precipitating coronary thrombosis. Characteristics of coronary atherosclerotic plaques underlying fatal occlusive thrombi, Br Heart J 50, 127-134 (1983). 

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