[Incidence, etiology and risk of rupture of aortic aneurysm. An autopsy study].

In an unselected series of 3,375 autopsies performed during five years there were 114 cases of aortic aneurysm (3.4%). Males were affected 9.4 times as often as females. Average age at death of those with aneurysm was 72.8 years, of those with rupture 69 years. Of the aneurysms 73.8% were located in the lumbar aorta, 22.8% in the thoracic aorta and 3.5% involved the entire aorta. Saccular or fusiform aneurysms accounted for 73.4%, dissecting ones for 18.4% and pseudoaneurysms for 1.8%. Arteriosclerosis was the underlying cause of the aneurysm in 95.6% of cases; in 41.2% rupture was the direct cause of death. Aneurysms of the thoracic aorta were ruptured in 65.4%, of the lumbar aorta in 32.1%. The incidence of rupture was highest for dissecting aneurysm of the thoracic aorta and the entire aorta--75% each. Hypertension was found to be a risk factor of rupture.