Compression of and by the vertebral artery

Abstract

The vertebral artery (VA) may be either intermittently or permanently compressed by different factors. Intermittent compressions are generally due to bony, ligamentous, or muscular anomalies or pathologies that require surgical treatment only when causing compression. They cause compression only during particular movements of the head and neck. Surgery must be pursued only if the same movement that produces symptoms also severely compresses the VA during dynamic angiography. Intermittent compressive factors typically include sympathetic elements in the first segment, osteophytic spurs and fibrous bands in the second segment, and rotational obstruction (bow hunter's syndrome) and C1–C2 instability in the third segment. Treatment must include resection of the compressive factor and opening of the adjacent transverse processes. A fusion procedure is performed in the case of instability. Permanent compression tends to be related to the development of turnors, but is also exceptionally symptomatic when due to occlusion. The VA may also be responsible for neurovascular compromise of the spinal cord or nerve roots. The cause is either tortuosity or congenital malformation (intradural course) of the VA.