Atherosclerosis Embolism

Thrombolytic Enzymes. Although atherosclerosis and the accompanying vascular wall defects are ultimately responsible for such diseases as acute pulmonary embolism, arterial occlusion, and myocardial infarction, the lack of blood flow caused by a fibrin clot directly results in tissue injury and in the clinical symptoms of these devastating diseases (54). Thrombolytic enzyme therapy removes the fibrin clot by dissolution, and has shown promise in the treatment of a number of thrombo-occlusive diseases (60). 

Ischemic stroke has numerous causes. Cerebral infarction may result from large artery atherosclerosis, cardiac embolism, small artery lipohyalinosis, cryptogenic embolism, or, more rarely, from other diverse conditions such as arterial dissection, infective endocarditis, and sickle cell disease. Arterial occlusion is the cause of at least 80% of acute cerebral infarctions. " ... 

Ischemic strokes account for 88% of all strokes and are due either to local thrombus formation or to emboli that occlude a cerebral artery. Cerebral atherosclerosis is a causative factor in most cases of ischemic stroke, although 30% are of unknown etiology. Emboli can arise either from intra- or extracranial arteries. Twenty percent of embolic strokes arise from the heart. 

Noninvasive detection of vascular abnormalities is of the utmost importance in clinical imaging. Indeed, a lot of injuries and diseases manifest themselves through modifications of the vasculature [1,2]. For example, abnormal angiogenesis (blood vessel growth) is observed in the development of most tumors. Embolism and atherosclerosis also manifest themselves through alterations of the blood vessels, namely through occlusions. Hemorrhage could also be detected noninvasively, which is crucial in injuries or in diseases such as ulcers [1]. 

Congestive cardiac failure, pulmonary embolism Atherosclerosis, stenoses... 

Aberrant thrombus formation and deposition on blood vessel walls imderlies the pathogenesis of acute cardiovascular disease states which remain the principal cause of morbidity and mortality in the industrialized world [1,2,3]. Plasma proteins, proteases and specific cellular receptors that participate in hemostasis have emerged as important risk considerations in thrombosis and thromboembolic disorders. The clinical manifestations of the above disease states include acute coronary artery and cerebrovascular syndromes, peripheral arterial occlusion, deep vein thrombosis and pulmonary/renal embolism [3]. The most dilabilitating acute events precipitated by these disorders are myocardial infarction and stroke. In addition, the interplay between hemostatic factors and hypertension (4) or atherosclerosis (5) dramatically enhances the manifestation of these pathologic states. 

Indications Prevent clot formation in patients with DVTs and pulmonary embolism, provide anticoagulation during hemodialysis, prevention of postoperative clot formation after surgery, decrease risk of strokes, decrease risk of Ml in patients with atherosclerosis Common drug examples ... 

Altered collateral circulation previous embolization, trauma/iatrogenic injury, atherosclerosis, shock, and pharmacological alteration (vasopressor therapy)... 

Approximately 795,000 people suffer from a stroke annually. In 2005, 1 in 17 deaths were caused by strokes [34]. Atherosclerosis in the neurovasculature is a leading cause of ischemic strokes, which make up 87% of all strokes [34]. The arteries become too narrow and blood cells start to collect and form a clot (thrombus). Thrombotic strokes occur when a clot blocks off blood flow, whereas embolic strokes occur when a clot breaks free and blocks flow further down the vasculature. In either case, the lack of blood flow to the brain cells for even a few minutes can cause irreparable cell damage or death. Therefore immediate treatment is necessary. 

The pathogenesis of arterial stenosis or occlusion may be secondary to a wide spectrum of etiologic factors including atherosclerosis, thrombosis, embolic events of various etiology, fibromuscular dysplasia, vasculitidies, dissection, trauma, external compression, and vasospastic syndromes. Atherosclerosis is by far the most common cause of arterial stenosis. 

Abdominal aortic aneurysms represent potentially life-threatening conditions that occur in up to 10% of the aged populations in industrialized nations. An aneurysm is broadly defined as a permanent localized dilatation of an artery. AAAs arise because of substantial remodeling of the extracellular matrix and are frequently accompanied by atherosclerosis. They may be manifested by catastrophic rupture, signs of pressure on other viscera, or an embolism originating in the aneurysm wall, but most are asymptomatic. 

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