Incision And Flaps

The exact location and type of skin incision will depend on the site of the primary tumor and whether a unilateral or bilateral neck dissection is planned. The following are the main goals to be achieved by the skin incision:

• Allow adequate exposure of the surgical field.

• Assure adequate vascularization of the skin flaps.

Figure 4-6 Some popular skin incisions for functional and selective neck dissection. (A) Gluck incision for unilateral and bilateral neck dissection. (B) Double-Y incision of Martin. (C) Single-Y incision. (D) Schobinger incision. (E) Conley incision. (F) Mac Fee incision. (G) H incision.

• Protect the carotid artery if the sternocleidomastoid muscle has to be sacrificed.

• Include scars from previous procedures (e.g., surgery, biopsy, etc.).

• Consider the location of the primary tumor.

• Facilitate the use of reconstructive techniques.

• Contemplate the potential need of postoperative radiotherapy.

• Produce acceptable cosmetic results.

A number of skin incisions may be used for neck dissection (Fig. 4-6). A popular incision in our practice is the classic Gluck incision (Fig. 4-6A), which is basically an apron flap incision, with a vertical posterolateral arm to approach the supraclavicular area. For a bilateral functional neck dissection the incision extends between both mastoid tips, crossing the midline at the level of the cricoid arch. This incision allows good exposure when the neck dissection is to be combined with total or partial laryngectomy. Sometimes the vertical arm can be avoided by prolonging the apron flap in a posteroinferior direction, thus producing a better cosmetic result. When the operation includes a total laryngectomy the tracheostomy is usually incorporated in the incision. On the other hand, for partial laryngectomies and other tumors requiring temporary tracheostomy, a small independent horizontal incision is made at the level of the second tracheal ring for the tracheostomy.

The double-Y incision of Martin (Fig. 4-6B) is also popular for functional and selective neck dissection. A chin extension may be used when the removal of the primary tumor requires an intraoral approach. A well-known disadvantage of this incision is the compromise to the blood supply, especially in the two crossings of the incision. Thus, the vertical arm of the incision should

be placed posterior to the carotid artery. The cosmetic result is improved by giving the vertical arm a slightly S-shaped curve.

The single-Y incision (Fig. 4-6C) avoids one of the crossings of the double-Y incision but makes the dissection of the supraclavicular fossa difficult.

The Schobinger flap (Fig. 4-6D) is also designed to protect the carotid artery by means of a large anteriorly based skin flap. However the blood supply to the posterosuperior part of the flap is not good and, occasionally, this area becomes devitalized.

The Conley modification (Fig. 4-6E) of the Schobinger flap brings the posterosuperior arm of the incision a little further anteriorly. The vertical arm of the incision is extended more posteriorly, toward the lateral third of the clavicle.

The incisions commonly used for radical neck dissection in previously irradiated patients may also be used for functional neck dissection. These include the Mac Fee parallel transverse incision (Fig. 4-6F) and the H incision (Fig. 4-6G). They both allow a good preservation of the blood supply to the skin flaps. The Mac Fee incision has excellent cosmetic results. However, the approach to the neck is not as good as with other incisions. Because a functional approach to the neck is not possible in previously irradiated patients where no fascial spaces remain after radiation, this incision is not commonly used for functional procedures. However, it may be useful for modified radical neck dissection when the extension of nodal disease allows preservation of some neck structures. Many other skin incisions may be used depending on the clinical characteristics of the lesion and the personal preference of the surgeon.

After the incision is completed, the skin flaps are elevated deep to the platysma muscle, preserving the superficial layer of the cervical fascia (Fig. 4-7). Preservation of the external lymphatic envelope allows further fulfillment of the basic anatomical principle of the functional approach (i.e., removal of the fascial walls of the lymphatic container along with the lymphatic tissue of the neck).

Figure 4-7 The skin flaps have been raised, preserving the superficial layer of the deep cervical fascia (right side). US, upper skin flap; SG, submandibular gland; tc, transverse cervical branch from the superficial cervical plexus; SC, sternocleidomastoid muscle; ga, great auricular nerve; Erb's point.

Figure 4-7 The skin flaps have been raised, preserving the superficial layer of the deep cervical fascia (right side). US, upper skin flap; SG, submandibular gland; tc, transverse cervical branch from the superficial cervical plexus; SC, sternocleidomastoid muscle; ga, great auricular nerve; Erb's point.

The limits for a complete functional neck dissection are similar to those of the classic radical neck dissection (Fig. 4-8). The surgical field should expose superiorly the inferior border of the mandible and the tail of the parotid gland. Inferiorly, the flap should be raised up to the level of the clavicle and the sternal notch. The midline of the neck will be the anterior border of the surgical field for a unilateral neck dissection. Finally, the posterior border of the sternocleidomastoid muscle in the upper part of the surgical field, and the anterior border of the trapezius muscle in the lower half of the neck, constitute the posterior boundary of the dissection. After the flaps have been raised, the underlying neck structures can be seen shining through the superficial layer of the cervical fascia (Figs. 4-7, 4-8).

The flaps must be protected by means of wet surgical sponges. Frequent moistening of the sponges will help to keep the skin flaps in good condition throughout the operation. It should be remembered that this may be a long operation since neck dissection is often performed in conjunction with removal of the primary tumor and, in some instances, reconstructive procedures. Thus, all efforts should be made to preserve the skin in good condition until the end of the procedure.

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