Truncus brachiocephalicus

Fig. 3. Variations of the great vessels branches from aortic arch (cynomolgus and marmoset monkey). 1=Arteria subclavia dextra, 2=Arteria carotis communis dextra, 5=Truncus brachiocephalicus, 4=Arteria carotis communis sinistra, 5=Arteria subclavia sinistra, =Arcus aortae.

The truncus brachiocephalicus and the left CCA show a combined origin from the aortic arch in approximately 25% of cases. The left vertebral artery rarely arises directly from the arch proximal to the subclavian artery. Infrequently an aberrant right subclavian artery leaves the aorta distal to the left subclavian artery and crosses the mediastinum dorsal to the esophagus and is then called the arte-ria lusoria (Fig. 5.10). Elongations and ectasias of the aortic arch and supraaortal vessels, which can impair the imaging quality of the vessels, are often seen in elderly patients. 

---