The pathophysiology of atherosclerosis.

Complications resulting from advanced atherosclerosis are the most common indication for vascular reconstructive surgery. Atherosclerosis is a systemic disease affecting the entire arterial tree, but lesions involving the coronary, extracranial cerebral, and lower extremity circulations have the most clinical significance for surgeons. The pathogenesis of atherosclerosis involves a complex series of events, similar to a chronic inflammatory process, with the formation of atherosclerotic plaque as the end result. Injury to the endothelial cell of the artery, resulting in endothelial cell dysfunction, is the first step in the process. Activated endothelial cells attract leukocytes and vascular smooth muscle cells (VSMC), which accumulate and proliferate in the arterial wall. These cellular components produce an excessive amount of connective tissue matrix. The ultimate end point is the formation of a mature fibrous plaque. Symptoms occur when advanced lesions are complicated by plaque rupture, hemorrhage into the plaque, emboli, or thrombosis. A thorough understanding of the pathogenesis of atherosclerosis is essential for the development of strategies for the prevention of the disease, and for the development of new and effective treatments.