Aortic Dimensions in a South Asian Population: Establishing Normative Data and Implications for Clinical Practice

Diameter of the aorta is a significant contributor and predictor for complications and a fundamental parameter for intervention. It is recognized that age, sex, and ethnicity play a role in aortic size. We thus sought to determine the normal dimensions among our population.A retrospective analysis of images was done of all polytrauma patients admitted between January 2018 and December 2022 who underwent protocolized noncontrast computed tomography of the chest and abdomen to measure the aortic diameter at established reference points.There were 513 patients; the mean age was 36.5 ± 14.6 (range: 18-86), and 382 (74.5%) were males. Aortic dimensions at sinus, mid-ascending, arch, descending, suprarenal, and infrarenal aorta were 30.7 ± 3.8, 29.3 ± 4.5, 24.9 ± 3.3, 20.1 ± 3.0, 19.4 ± 2.9, and 15.3 ± 2.2, respectively. Age demonstrated a positive correlation to the diameter at the ascending, descending, and infrarenal aorta (r = 0.58, p = 0.001 [95% confidence interval, CI = 0.519; 0.634]; r = 0.69, p = 0.001 [95% CI = 0.641; 0.732]; r = 0.57, p = 0.001 [95% CI = 0.509; 0.626]) along with the length of the ascending aorta (r = 0.420, p = 0.001 [95% CI = 0.345; 0.488]; r = 0.536, p = 0.001 [95% CI = 0.471; 0.595]; r = 0.476, p = 0.001 [95% CI = 0.406; 0.540), respectively. There was a positive correlation of aortic diameters to body mass index (BMI), systolic blood pressure (SBP), and diastolic blood pressure (DBP). Females had smaller dimension at the reference points, but without any statistical significance. There were 50 (9.8%) patients with bovine aortic arch and 10 (1.9%) with separate origin of left vertebral artery.Normal values of the diameter of the aorta for a South Asian population are provided. Diameter is affected by age, length of the ascending aorta, BMI, SBP, and DBP. This study suggests that the aorta size is smaller in the South Asian population than the referenced Western population, more significantly for distal descending and abdominal aorta and that ethnicity plays a role in determining aortic dimensions.