Variation of infrarenal aortic diameter: A necropsy study

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.