ANOMALOUS ORIGIN OF LEFT VERTEBRAL ARTERY ARISING FROM THE ARCH OF AORTA AND ITS EMBRYOLOGICAL BASIS

Background and aim: Arterial disarrangements within the thorax are common and assume many diverse forms. The anatomic and morphologic variation of the origin and course of the prevertebral segment of the vertebral artery is necessary for vascular radiology, planning of aortic arch surgery or endovascular interventions. The present study is aimed at finding the origin and course of the left vertebral artery from the arch of aorta between left common carotid and left subclavian arteries. Materials and methods: Present study was done on six formalin fixed cadavers during routine dissection allotted for the first year students of Kanyakumari Government Medical College Asaripallam, Nagercoil (2012-2013). The direct dissection method was used. A comparative analysis was done with previous studies. Result: Usually the vertebral artery arises from supero-posterior aspect of the first part of the subclavian artery. But in a 60 yrs old adult female cadaver showed a variation, that the arch of aorta gave off four branches in which the left vertebral artery arose as 3rd branch between the left common carotid and left subclavian arteries. Conclusion: Variation observed in the study is in par with variation observed in previous studies. The knowledge about the variant origin of left vertebral artery is necessary for interventional radiologists and surgeons to avoid complications in the head and neck region.