Neurosurgery for Extracranial Vertebral Artery Disease

Abstract

The extracranial vertebral artery (VA) extends from the subclavian artery to the dura mater, at the level of the foramen magnum. It is subdivided into three segments. The V1, or ostial segment, courses through the soft tissue at the base of the neck upwards towards the C6 transverse foramen. The V2, or transversary segment, ascends to the C2 transverse foramen, passing inside the transverse foramen of each cervical vertebra. The V3, or suboccipital segment, runs to the C1 transverse foramen, where it courses above the C1 posterior arch before entering the dura mater. Each segment presents its own specific variations. Basic preoperative exams comprise CT scan and MRI, with angiographic sequences, conventional and dynamic angiography, and Doppler ultrasounds. Knowledge of the arterial dominance and the risk of VA injury will aid in determining the need for a balloon occlusion test (BOT). The anterolateral approach is the method of choice for exposing the VA V1 and V2 segments. The VA V3 segment can be reached either by an anterolateral or a posterolateral approach, depending on the location and extent of the lesion. By ensuring a precise surgical technique is followed, and that VA exposure is controlled, a wide variety of pathologies associated with the VA may be treated. ©2015 Springer-Verlag Berlin Heidelberg, All rights reserved.