Purpose: To determine anatomicomorphological changes in the infrarenal port
ion of the abdominal aorta, we performed 645 dissections of the segment in
corpses undergoing necropsy.
Methods: The aortas were removed from the corpses with a surgical technique
; by means of a device that are designed, the external diameter of the arte
ry was measured after luminal pressure was reestablished. This way, it was
possible to avoid underestimation of the arterial diameter postmortem. The
influence of age, sex, body size, arterial hypertension, chronic obstructiv
e pulmonary disease, and coronary disease on the aortic diameter and the in
fluence of different degrees of sclerosis on the infrarenal aorta wall were
analyzed. Considering the diameters, aortas were regarded as "normal" when
they did not present any ectasia, arteriomegaly, aneurysm, or hypoplasia.
Results: The sample involved 645 subjects whose ages ranged from 19 to 97 y
ears (mean age, 55.8 years). Of the 645 subjects, 65.5% (423) were men, 34.
5% (222) were women, 81% (523) were white, and 19% (122) were of another ra
ce. The diameters of arteries showing no anomalous dilatation (ectasis, art
eriomegaly, or aneurysm) varied according to subject age, sex, body length,
and the degree of atherosclerosis on the aorta wall (P < .01). Aortic diam
eters of those subjects with arterial hypertension, coronary disease, and c
hronic obstructive pulmonary disease were compared with the aortic diameter
s of control subjects, and significant differences were not shown (P > .05)
. Twenty-nine aneurysms were found (4.5% prevalence). Pour were ruptured an
eurysms, and all occurred in aortas with diameters larger than 5.0 cm.
Conclusion: The infrarenal aortic diameter enlarges with aging, and this en
largement occurs earlier in men than in women. Those subjects who had a lon
ger body length and advanced sclerosis on the aorta wall had larger aortic
diameters. There was a high prevalence of infrarenal aneurysms (4.5%), with
rupture found solely in aortas with diameters larger than 5.0 cm.