Direct Aortic Origin of the Left Vertebral Artery in Two Adult Female Cadavers

Abstract

BackgroundThe vertebral artery (VA) is a branch of the aortic arch which usually arises from the posterosuperior aspect of the first part of the subclavian artery and ascends medially to the transverse process of the seventh cervical vertebra and continues ascending through the transverse foramina of the upper six cervical vertebrae to enter the skull via the foramen magnum. It is an important blood supply of the spinal cord, vertebral muscles, hindbrain and contribution to the circle of Willis.ResultsDuring routine dissection of the superior mediastinum and neck of two adult female cadavers the left VA was observed originating directly from the aortic arch rather than the left subclavian artery. In one cadaver the left VA entered the transverse foramen of the fifth cervical vertebra (CV5), while in the other cadaver it entered the typical the sixth cervical vertebra (CV6) transverse foramen. The diameter and length of the vessel that entered CV5 maintained the same diameter of 5mm from its origin to its position on the posterior arch of the atlas and measured 95mm in length from its origin to its entrance at CV5. In the other cadaver, the diameter decreased from 4mm, at its origin, to 3mm as it entered CV6. As it ascended from its origin it took a highly coiled approach and measured 60mm in length from its origin to it entrance in CV6. Direct aortic origin of the left vertebral artery is the most frequent anatomic variant of the vertebral artery with an incidence ranging from 2.4–5.8%.ConclusionKnowledge of this variation is important to reduce the risk of vertebral artery injury in angiography and surgical approaches.Support or Funding InformationCenter for Anatomical Science and Education, Department of Surgery, Saint Louis University School of MedicineThis abstract is from the Experimental Biology 2019 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.