RIGHT VERTEBRAL ARTERY : ANOMALOUS PREVERTEBRAL COURSE AND DISTRIBUTION

Abstract

Vertebral artery (VA) is the largest branch of the first part o f the subclavian artery and the chief source of blood supply to brainstem, cerebellum, occipital lobe o f cerebrum and posterior cranial fossa. Anomalous origin, course and or branching pattern of VA may lead to disturbance in veitebro-basilar hemodynamics, risking cerebro-vascular insufficiency. A unique case of right VA having usual origin, but anomalous course and branching pattern in its prevertebral segment is described. Moreover the right thyrocervical trunk was absent in present case and inferior thyroid artery branched off the variant VA. The ligation o f such vertebral artery may cause a compromise to thyroid in addition to posterior cranial fossa blood supply. The information about its course is crucial during diagnostic investigations and surgical procedures in the head and neck region.