Subaxial Positional Vertebral Artery Occlusion Corrected by Decompression and Fusion

Abstract

A rare case of subaxial vertebral artery (VA) positional occlusion is reviewed and treatment methods discussed. The decision process involved in treating subaxial VA positional occlusion is reviewed. Bow Hunter stroke is a symptomatic vertebrobasilar insufficiency caused by stenosis or occlusion of the VA with physiologic head rotation. It most commonly occurs at the junction of C1 and C2 and less commonly as the VA enters the C6 transverse foramen. Rotational stenosis of the VA is quite rare during its passage through the foramen transversarium of C3-C6. A 48-year-old gentleman presented describing syncopal episodes when he turns his head to the left side. Imaging revealed a congenitally narrowed right foramen transversarium and high-grade stenosis of the left VA when the head was turned to the left. A routine anterior cervical discectomy and fusion was performed with the addition of decompression of the left transverse foramen. Vascular imaging should be performed with the patient's head in both the neutral position and in the symptomatic position. Surgical treatment may be chosen if conservative therapies fail and generally has 1 of 2 goals-decompression of the VA or elimination of rotational movement at the affected level. Decisions between anterior and posterior decompressions may be influenced by the surgeon's comfort level with the approach and if the transverse foramen stenosis is caused mainly by an anterior (osteophytes at the uncinate process) or posterior (facet joint hypertrophy) process. The patient remains symptom-free after treatment. This report demonstrates the condition in the subaxial spine and describes successful treatment by fusion of the affected level combined with decompression of the foramen transversarium-a combination of previously described therapies.