[Infrarenal aortic aneurysm. 1. Etiology and biomechanics]

The etiology of infrarenal, "nonspecific" aortic aneurysms was previously believed to be degenerative arteriosclerosis, but recent studies of the components of the aortic wall have shown that complicated disturbances primarily concerning the synthesis and degradation of elastin and collagen are major pathogenetic components. Non-invasive measurements of the biomechanical properties of the aneurysms and determinations of the directions and forces of local flow velocity vectors within the aneurysmatic sac have provided new knowledge of the abnormal physical factors that follow dilatation. Detailed studies on the biochemical and physiological factors will make it possible to identify patients at risk and provide the foundations for interventions that will prevent development of the disease.