ANTEROLATERAL APPROACH TO THE V2 SEGMENT OF THE VERTEBRAL ARTERY

OBJECTIVE: We describe our surgical technique of exposure and control of the second segment of the vertebral artery (VA V2 segment). Our basic principle is that working in the VA vicinity is more confident under visual control. METHODS: The VA V2 segment extends classically in and between the transverse processes from C6 to C2. This segment can be exposed through an anterolateral approach, passing medially to the sternocleidomastoid muscle and laterally to the internal jugular vein. Except in case of anatomic variation, the VA V2 segment is protected by the transverse processes bone, even if a pathological process displaces the VA along its course between them. The safest technique to expose the VA V2 segment then is to reach first the transverse process by cutting the longus colli muscle. Afterward, dividing intertransversary muscles permits exposure of and safely controls the VA by following its course. If required, the VA V2 segment can even be freed by opening the transverse process as far as the dissection is performed in the subperiosteal plane. In fact, the VA V2 segment is surrounded by a venous plexus and a periosteal sheath. This sheath gives a plane out of which the dissection is safe, avoiding troublesome venous bleeding or VA damage. RESULTS: This technique is very efficient for degenerative disorders, hour glass tumors, and vascular surgeries. CONCLUSION: Exposure and control of the VA V2 segment is safe if anatomy and variations are perfectly known, and if a rigorous step-by-step surgical technique is followed.