Lateral Approach to the Cervical Spine (Verbiest)

Abstract

This lateral approach is a direct approach to the spinal nerve and the vertebral artery in the intervertebral foramen [ 1 ]. 1. Position the patient supine with a slight roll under the shoulders. The head is not rotated. 2. Incise the skin with a transverse collar-type incision for one-or two-level disease and with a longitudinal incision along the medial border sternocleidomastoid for multi-level disease. With retraction of the skin and subcutane-ous tissue, the platysma muscle is divided longitudinally in line with its fi bers. The superfi cial layers of the investing cervical fascia are opened to identify the medial border of the sternocleidomastoid muscle and the interval between sternocleidomastoid and the medial strap muscles. Angled retractors are used by the assistant to open this interval. 3. Identify the great auricular nerve and the anterior cuta-neous nerve. These cutaneous branches of the cervical plexus penetrate the deep fascia on the posterior surface of the sternocleidomastoid muscle at approximately midbelly. The great auricular nerve crosses in a cephalad direction on the surface of the sternocleidomastoid muscle toward the ear. The anterior branch of the greater auricular nerve innervates the skin over the face in the area of the parotid gland. The anterior cutaneous nerve takes a more horizontal course across the sternocleido-mastoid before dividing into ascending and descending branches. The ascending branch of the anterior cutane-ous nerve pierces the platysma muscle and is distributed to the skin overlying the mandible. Loss of sensation from damage to this nerve can result in decreased sensation over the mandible [ 2 ]. 4. Retract the sternocleidomastoid muscle laterally. When retraction is diffi cult, the sternocleidomastoid muscle is separated from its attachment to the mastoid process. In any separation of the proximal mastoid, cranial nerve XI must be identifi ed entering the sternocleidomastoid two to three fi ngerbreadths below the mastoid tip and the proximal third of the muscle. The spinal accessory nerve exits the muscle obliquely caudally, passing across the posterior triangle of the neck to the ventral border of the trapezius. 5. With lateral retraction of the sternocleidomastoid muscle , identify by fi nger palpation the carotid sheath. Open the middle cervical fascia with Metzenbaum scissors and dissect longitudinally with fi ngertips to expand the interval between the sternocleidomastoid muscle and the carotid sheath laterally and musculovisceral column medially. Retract the medial structures with a blunt-angled retractor, and palpate the carotid pulse and the anterior tubercle of the transverse process. Ligate and divide any tethering vessel. Divide the omohyoid muscle, if needed. 6. Identify the anterior tubercle of the transverse process (Figs. 8.1 , 8.2). This prominent process is suitable for insertion of longus coli, longus capitis, and anterior sca-lene muscles, and is the key to dissection. 1 , 3 , 4 Palpation of the spine under the prevertebral fascia reveals the disc spaces, the anterior tubercle of the transverse process, and, medial to the tubercle, the longitudinal groove of the costotransverse lamellae (Figs. 8.1 , 8.2). It is approximately the size of a small fi ngernail, joins the anterior tubercle to the vertebral body, and is the roof of the foramen transversarium covering the vertebral artery [ 3 ]. The prominent Chassaignac's tubercle, the anterior tuber-cle of C6, is a relatively consistent landmark, but every level should be identifi ed with X-ray control after exposure of the anterior tubercle of the transverse process. 7. Open the prevertebral fascia with scissors and extend it longitudinally. Visualize the longus coli and longus capitis muscles on the spine. The longus coli muscle, a three-belly muscle broad in the middle and narrow at the end running from C2 to T3, consists of a vertical and an oblique portion. The vertical portion arises and inserts on the anterior surface of the vertebral bodies.