Anterior Cervical Approach for Bow-Hunter's Syndrome

Abstract

  Here, we report two cases of patients with bow-hunter's syndrome at the C1-C2 level who underwent anterior decompression of the vertebral artery. Aged in their 70s and 80s, both patients presented with blurred vision or dizziness induced by left neck rotation. Magnetic resonance angiography and computed tomography angiography revealed occlusion or hypoplasia of the left vertebral artery. Left neck rotation produced anteromedial movement of the C1 transverse process and traction of the right vertebral artery, resulting in stenosis of the right vertebral artery in the C2 transverse foramen. Using the anterior cervical approach, the right C3 and C2 transverse processes were exposed by detachment of the longus colli muscle. Following identification of the right vertebral artery between the C2-C3 transverse processes using a Doppler probe, the surface of the right C2 transverse foramen was carefully drilled through and opened. The preoperative symptoms disappeared postoperatively in both cases. The anatomical relationship between the vertebral artery and the C1 transverse process and rotatory stenosis of the vertebral artery at the C1-C2 level will be most effectively prevented by anterior decompression of the C2 transverse foramen rather than posterior decompression of the C1 transverse foramen. Using appropriate surgical techniques, the anterior cervical approach can effectively treat C1-C2 bow-hunter's syndrome with preserved neck motion.