Age and sex and their influence on the anatomy of the abdominal aorta and its branches

BACKGROUND: It is not clear how patients’ age and sex influence the anatomy of the aorta and its branches. OBJECTIVES: To determine the most frequent anatomical patterns of diameter and angulation of the abdominal aorta and its branches and the influence of patients’ sex and age on these patterns. METHODS: CT scans with intravenous contrast from 157 patients were analyzed. Diameter and angulations of the abdominal aorta and its branches were measured in individuals of both sexes, classified into five age groups: 20 to 30 years, 31 to 40 years, 41 to 50 years, 51 to 60 years, and 61 to 70 years. Eighteen variables were analyzed: 6 arterial origin angles, 9 arterial diameters, rate of diameter enlargement, and patient’s sex and age. RadiAnt 4.2.1 DICOM viewer software was used for measurements. RESULTS: The total of 157 CT scans were from 69 men and 88 women. There were statistical differences (p <0.05) in the following results: angle of origin and diameter of the superior mesenteric artery; renal artery angle and diameter; diameter of the common iliac arteries, and diameter and rate of diameter enlargement of the aorta in several segments, but not the segment immediately proximal to the celiac trunk. CONCLUSIONS: The diameters of several aorta segments and of its branches (except the left renal artery) increase progressively with age in both sexes and are larger and have a higher rate of diameter enlargement in men than in women in the same age ranges. Between sexes, the angle of origin of the superior mesenteric artery was larger in men, except between 20 and 30 years, and the angle of origin of the left renal artery was larger in women between 51 and 60 years old.