| Popis: |
Abdominal aortic aneurysms are the result of a destructive process of the aortic media. The incidence of abdominal aortic aneurysms is increasing but the reasons remain unknown. The mechanical and structural characteristics of the abdominal aorta explain the frequency of acquired aneurysms at this location. Classically, atherosclerosis is the main etiologic factor, but the abdominal aortic aneurysm is distinguishable from the aged aorta and occlusive atherosclerotic disease by the apparent absence of a reparative process. Some authors have tried to differentiate aneurysmal disease from occlusive atherosclerotic disease. Atherosclerosis could lead to plaque and stenosis or, in some unknown circumstances, to atrophy of the media and aneurysmal dilation. Proteolytic enzymes within the aortic wall play an important role in the destruction of the extracellular matrix of the aortic wall. Plasmin could locally worsen the proteolysis. Inflammatory cells might be responsible for these proteolytic activities. Calcium could play a role in the activation of inflammatory cells. Genetic markers and familial grouping have been reported by several authors. The discovery of constitutional or acquired factors that could lead to activation of degradative phenomena within the aortic wall will facilitate the identification of patients at risk, and improve screening of asymptomatic aneurysms. |
