Study on Five Cases of an Accessory Left Vertebral Artery on the Aortic Arch

Vascular variations of the head and neck are common, but often go unnoticed because they generally do not present clear clinical symptoms. Lack of awareness of the presence and location of such variations may result in iatrogenic complications or even fatalities. Physicians and surgeons should be cognizant of such variations given their potential clinical significance.

Vertebral artery variations are prevalent in both number and origin, but documented infrequently in the literature. Each of the five case studies described here: a White 65-year-old male (Case 1), a White 89-year-old female (Case 2), a White 80-year-old female (Case 3), a White 96-year-old female (Case 4), and a White 95-year-old female (Case 5), presented with an accessory left vertebral artery originating from the aortic arch, between the left common carotid artery and the left subclavian artery. This is the most common place for variations of this type in the literature. All five cases, however, also presented with a left vertebral artery branching from the left subclavian artery. For Cases 1 and 3, the accessory left vertebral artery coursed cranially and entered the foramen transversarium at the C5 level. For Case 2, it entered at the C3 level. For Cases 4 and 5, it entered at the C4 level. With a prevalence rate of 7.81%, among a population of 64 donors randomly selected and undergoing cadaveric review, this anatomical variant illustrates the potential frequency, and thus, the clinical importance of extensive anatomical understanding of head and neck vascular variations.