A rare variant of double origin of the left vertebral artery.

The vertebral artery (VA) demonstrates considerable variability, including infrequent morphologic variants like double origin. The current imaging report presents an atypical case of a dual origin of a left vertebral artery (LVA), which was identified incidentally during routine computed tomography angiography of a 51-year-old male patient. The typical LVA originated from the left subclavian artery (LSCA), and the other one was an aberrant LVA (ALVA) that arose from the aortic arch (AA) in between the left common carotid artery (LCCA) and the LSCA. The two vessels (LVA and ALVA) converged proximally to the transverse process of the C6 vertebra. The embryological explanation for this variant likely pertains to the persistence of primitive dorsal aortic segments and intersegmental arteries. Although rare, with a prevalence of 0.1%, the occurrence of LVA double origin may have significant clinical implications, including alterations in hemodynamics, an increased risk of VA dissection, and complications during surgical or endovascular procedures. The identification of such variants through preoperative imaging is essential to prevent iatrogenic complications.