Analysis of origin of the supra-aortic trunks from the aortic arch

The objective of this study was to describe in the general population the anatomy of the supra-aortic trunks (SATs: brachiocephalic trunk [BCT], left common carotid artery [LCCA], and left subclavian artery [LSA]) arising from the aortic arch in terms of mutual distances from the valvular aortic plane (VAP), ostial diameters, and clock face orientation from the sagittal aortic axis, with an analysis of each distribution.

Measurements of 252 computed tomography angiograms of the aortic arch and SATs in three groups of patients (84 without any disease of the aortic arch, group A; 84 with dilation of the aortic arch, group B; 84 with dilation of the descending thoracic aorta below the LSA, group C) were retrospectively collected and analyzed. The Shapiro-Wilk test was used to assess normality of each distribution.

The ostial diameters of the SATs followed a gaussian distribution in all groups. In group A, only VAP-BCT and LCCA-LSA distances were normal, being in 95% of cases between 46.6 and 88.2 mm and between 8 and 23.3 mm, respectively. In both groups B and C, the distance VAP-BCT and the takeoff angle of both LCCA and LSA were gaussian distributed (being in 95% of cases between 48.5 and 102.1 mm, -17.6° and 33°, and -17.7° and 23.4°, respectively, in group B; and between 51.3 and 101.1 mm, -28.2° and 33.7°, and -28.7° and 31.3°, respectively, in group C). VAP-BCT distance and BCT angle were lower in group A compared with group B (P < .001 and P = .008, respectively) and group C (P < .001 and P = .04, respectively). Irrespective of the group, all SAT mutual distances and ostial diameters were related to the aortic diameters, being greater for increasing aortic diameters. Neither BCT angle nor LSA angle was related to the aortic diameters, whereas LCCA angle was inversely correlated.

Most of the analyzed variables did not show a gaussian distribution, both in healthy and in diseased patients. Irrespective of the group, all SAT mutual distances and ostial diameters were related to the aortic diameters, being greater for increasing aortic diameters.