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).

Figure 17.6 Cutaneous nerve supply of the superficial cervical plexus.

The external jugular vein runs vertically downward across the sternocleidomastoid muscle and dives into the deep fascia at the base of the neck. The other large arteries and veins are protected by the muscles of the neck.

The platysma muscle is the superficial muscle of the anterior neck. This paper-thin muscle is embedded in the superficial fascia, which is continuous with the superficial musculoaponeurotic system (SMAS) of the face. The platysma muscle tenses the neck and pulls the lower lip downward. It covers most of the anterior triangle of the neck, but only covers a small inferior corner of the posterior triangle. It does not cover the path of the spinal accessory nerve as it courses through the mid-section of the posterior triangle.

RECONSTRUCTIVE OPTIONS

The three best reconstructive options for repairing a defect on the neck are primary closure, primary closure, and primary closure. Because the neck is a large reservoir of loose and lax skin, it becomes a convenient location to perform surgery. Even in the younger patient, the skin tension lines are often apparent. When planned with the patient properly positioned as mentioned earlier, a surgeon can take advantage of the laxity and skin tension lines, and consistently provide a superior cosmetic outcome. When a wound is on the lateral neck, every effort should be made to orient the repair inside or parallel to the relaxed skin tension lines. When this is done, even remarkably large wounds can be brought together in a primary closure with surprising ease.

In the following example, a basal cell carcinoma was removed from the right lateral neck. The resulting defect was 11.2 × 5.7 cm² in size (Figure 17.7), and was closed in a primary fashion (Figure 17.8). The patient is pictured six months later in Figure 17.9.

Figure 17.7 Large defect on the neck following Mohs micrographic surgery.

Figure 17.8 Primary closure of neck large neck wound.

Figure 17.9 Scar following primary closure at six-month follow-up.

Because a primary closure is such a great option for surgical defects of the neck, it is rare that a flap or skin graft is required. Of the many flaps that may be available, transposition flaps including rhombic and bilobed flaps may be helpful for recruiting skin and laxity from distant locations. Split-thickness skin grafts and full-thickness skin grafts are also possibilities when the other options for repair are limited. However, the morbidity of a large skin graft and its donor site may outweigh the benefit to the primary defect. Wounds on the neck can also do well when they are allowed to heal by secondary intention.

When wounds are oval, and the long axis is vertically oriented, orienting the closure in a transverse skin tension line can be a challenge. When a more vertical orientation is required, Z-plasties can be used to keep the tension vectors as transverse as possible. When wounds are located in the anterior midline of the neck, the defect can be closed vertically in the midline. However, a band-like scar may result from this, requiring scar modification with a Z-plasty to lengthen the scar and shift tension vectors.

Most wounds on the posterior neck can be closed primarily along skin tension lines just like on the lateral neck. However, the posterior neck is also a good location for a wound to heal by secondary intention. Even incredibly large wounds on the posterior neck can heal into remarkably thin scars. Some would argue that wounds in this area actually heal better when left to granulate than when closed primarily. The authors have treated several patients with acne keloidalis nuchae or hidradenitis suppurativa with wide excisions, and allowed them to granulate. The results are consistently excellent. Figure 17.10 shows a patient immediately after a wide excision of acne keloidalis nuchae on the posterior neck, and Figure 17.11 shows his final result after healing by secondary intention.

Figure 17.10 Posterior neck wound following wide excision of acne keloidalis nuchae.

Figure 17.11 Final scar after neck wound was allowed to heal by secondary intention.

Neck wounds that extend onto the mastoid region can be a challenge to close because the mastoid does not share the same laxity of the neck. This is another region that does remarkably well with secondary intention healing. Pictured in Figure 17.12 is a patient with a large defect of the neck, mastoid, and posterior ear. Figure 17.13 shows the wound healing well at 4 weeks. The healing wound is shown again at 4 weeks from a different angle in Figure 17.14, and it is already possible to see that the final result will be comparable to anything that could have been achieved with a flap or graft. The contracting forces of wound closure worked to the patient’s advantage, shrinking the size of the scar as it pulled the neck skin towards the defect.

Figure 17.12 Large defect on the neck and mastoid following Mohs micrographic surgery.

Figure 17.13 Wound healing by secondary intention, four weeks after Mohs surgery.

Figure 17.14 Another view of the wound at four weeks after surgery.

Other good options for repairing defects in the mastoid region are the rhombic transposition flap and an advancement flap. Both flaps allow the surgeon to borrow from the laxity of the neck and transfer the tissue onto the mastoid region (see Figures 17.15, 17.16).

Figure 17.15 Rhombic transposition flap.

Figure 17.16 Advancement flap.

Lastly, we must mention the musculocutaneous flap, which can be used to repair very large wounds that result from deep dissections of the neck. Musculocutaneous flaps involving the trapezius, latissimus dorsi, and pectoralis major muscles can be used. These flaps are helpful after large masses are removed from the deep musculature of the neck or the floor of the mouth, leaving defects both deep and wide.

REGIONAL PEARLS/COMPLICATIONS

When operating on the neck, the surgeon must always be mindful of the possibility of airway compression and obstruction. In cutaneous surgery, it is not usually an issue, but one must always be aware of it.

Additionally, on the neck, hemostasis must be meticulous. A dressing that applies significant pressure is not an option on the neck. Furthermore, the neck is highly mobile, and the neck will routinely undergo considerable movement after surgery. This movement can open vessels that are not completely ligated or coagulated. Additionally, the neck is at high risk for hematoma development because it can easily expand. In many locations, simply suturing a wound closed applies a small amount of pressure that can help vessels coagulate, but this is not true of the neck. The laxity of the neck will provide ample space for a hematoma.

SUMMARY

The majority of wounds on the neck are relatively easy to repair because of the excess skin and the abundant laxity of the neck. Most can be nicely repaired with a primary closure, and the best results are obtained when the repair is oriented in the relaxed skin tension lines. Occasionally a flap or skin graft is helpful, especially in the mastoid region.