PREOPERATIVE CONSIDERATIONS

Correct positioning of the patient is crucial when operating on the neck. A patient in the wrong position during surgery can lead to a poor cosmetic outcome as well as an awkward posture and subsequent discomfort on behalf of the surgeon.

When the surgical site is located on the anterior or posterior neck, common sense dictates that the patient should be in the supine or prone position, respectively. However, when one is operating on the lateral neck, there is a tendency to have the patient in the supine position with his head turned away from the surgeon to expose the surgical field. With the patient in this position, the tension vectors are distorted by twisting, and it is easy to repair a defect in a manner that distorts the natural skin tension lines. This can result in unwanted standing cones or scars that are not well camouflaged.

When planning a surgical repair, the patient should be looking straight ahead without twisting the neck. The best cosmetic results will be obtained when the surgeon plans his closure while the patient is in the sitting position with his neck slightly flexed. With the patient sitting, the natural skin tension lines and tension vectors of the neck can be accurately assessed. After the closure is planned and drawn out, the patient can then be placed in the appropriate position for surgery. When this is done, it is not difficult to hide most scars in the natural lines of the neck.

Positioning the patient appropriately during surgery on the neck is also important in order for the physician to maintain good posture. Oftentimes just a few extra minutes of planning and positioning the patient will help the surgeon reduce back and neck strain.

RELEVANT ANATOMY

The anterior neck has been divided into anterior and posterior triangles (Figure 17.1). The boundaries of the anterior triangle of the neck are the anterior margin of the sternocleidomastoid muscle, the inferior margin of the mandible, and the midline.

Figure 17.1 Anterior and posterior triangles of the neck.

The borders of the posterior triangle of the neck include the posterior margin of the sternocleidomastoid muscle, the anterior margin of the trapezius muscle, and the clavicle.

The most important anatomic structure to avoid during cutaneous surgery on the neck is the spinal accessory nerve (cranial nerve XI). This nerve emerges from under the sternocleidomastoid muscle and travels diagonally downward until it dives under the trapezius muscle (Figure 17.2). Because it innervates the trapezius muscle, damage to the spinal accessory nerve will result in winging of the scapula, difficulty in arm abduction, and shoulder pain. Erb’s point is the location where the spinal accessory nerve emerges from under the sternocleidomastoid muscle. It can be located by bisecting a horizontal line that connects the mastoid process and the angle of the mandible, and dropping a perpendicular line 6 cm inferiorly to where it intersects the posterior border of the sternocleidomastoid muscle (Figure 17.3).

Figure 17.2 Nerves of the neck.

Figure 17.3 Erb’s point.

It is surprising how easily the spinal accessory nerve can be reached during surgery. Only the skin, subcutaneous fat, and superficial fascia protect it. In patients with thin skin and minimal adipose tissue, it can be remarkably superficial (Figures 17.4, 17.5).

Figure 17.4 Basal cell carcinoma located over the spinal accessory nerve.

Figure 17.5 Spinal accessory nerve (arrow) is visible after removal of basal cell carcinoma.

The superficial cervical plexus also emerges near Erb’s point from the posterior border of the sternocleidomastoid muscle, and includes the following sensory nerves: the lesser occipital nerve, the great auricular nerve, the transverse cervical nerve, and the supraclavicular nerve. These nerves provide sensation to an area that begins with the anterior and lateral neck and moves superiorly to include much of the ear and mastoid region (Figure 17.6).