Atlas of General Surgical Techniques (Courtney M. Townsend Jr., B. Mark Evers)

Level III: The mid-jugular extends from the hyoid bone superiorly to the level of the cricoid cartilage inferiorly and to the posterior border of the SCM muscle.

Level IV: The lower jugular extends from the level of the cricoid superiorly to the clavicle inferiorly and to the posterior border of the SCM muscle.

Level V: The posterior triangle (spinal accessory and transverse cervical) is bounded by the anterior border of the trapezius muscle posteriorly, the posterior border of the SCM muscle anteriorly, and the clavicle inferiorly. Sublevel VA (spinal accessory nodes) is separated from VB (nodes following the transverse vessels) by a horizontal plane marking the inferior border of the anterior cricoid arch.

Level VI: Contains the prelaryngeal (Delphian), pretracheal, and paratracheal (anterior central compartment) nodes and extends from the hyoid bone superiorly to the suprasternal notch inferiorly and laterally to the medial border of the carotid sheath bilaterally.

Level VII: The upper mediastinal is inferior to the suprasternal notch in the superior mediastinum.

STEP 2: PREOPERATIVE CONSIDERATIONS

Neck dissections are often done in conjunction with resection of the primary tumor. In this case, the neck incision may be modified to include resection of both nodal disease and the primary tumor. A tracheotomy may also be necessary.

Indications for MRND with preservation of the SAN include the following:

The presence of a clearly defined plane between the SAN and tumor

Bulky nodal disease (stage N2, N3)

Persistent or recurrent nodal disease following radiation/chemoradiation therapy

Preoperative counseling must include the possibility of sacrifice of cranial nerves if involved with tumor, as well as the resulting deficits.

Two units of packed red blood cells are typed, screened, and held for transfusion if necessary.

Perioperative antibiotics are given if the upper aerodigestive tract is to be entered to resect the primary tumor.

The patient’s airway should be discussed with the anesthesiologist before surgery. The presence of a primary tumor, laryngeal edema, or effects of previous radiation therapy may dictate fiber-optic intubation or awake, local tracheotomy.

The proximity of nodal disease to the carotid sheath must be assessed for resectability. Carotid artery balloon test occlusion is performed if there is suspicion of carotid artery invasion. This will determine risk of cerebrovascular accident (CVA) if the carotid artery is resected. Carotid artery resection with or without reconstruction using saphenous vein graft is typically not considered except in radiation failures and recurrent disease.

The surgeon must be able and prepared to modify the surgical plan and the order in which various steps are performed if the tumor dictates such.

Anterior jugular vein

Sternocleidomastoid muscle

Superior thyroid artery and vein

External jugular vein

Thyroid gland

SCM clavicle head

SCM sternal head

MC

A

FIGURE 2–1

STEP 3: OPERATIVE STEPS

1.INCISION

Following oral endotracheal intubation or tracheostomy, the patient is placed supine. The neck is extended using a shoulder roll, and the head is stabilized using a doughnut cushion. The ipsilateral arm is tucked and the bed is turned with the operative field facing out (away from the anesthesiologist).

Following induction of general anesthesia, muscle relaxants are not used. This allows testing of cranial nerves with a nerve stimulator. This must be communicated to the anesthesiologist.

The surgical site is sterilely prepped with betadine from the level of the lower lip to right above the nipples, including the lower face, earlobe, and posterior neck. The prep is extended across the midline of the neck. If the primary tumor is to be resected, this area is also sterilely prepped in continuity with the neck and chest.

The sterile drapes surrounding the head and neck field are stapled or sutured to the patient.

There are many options for skin incisions, with the most commonly used ones seen here (Figure 2-1, C [half H], Figure 2-1, D [modified Schobinger], Figure 2-1, E [hockey stick]). The incision chosen depends on tumor location, including the primary tumor, and surgeon preference. I prefer the hockey stick incision that slightly crosses midline (See Figure 2-1, E) to avoid dropping a limb. If a limb is dropped, the trifurcation should be placed posterior to the carotid artery. In the event of skin necrosis, the carotid artery would not be exposed with this design.

The incision is outlined on the neck using a sterile marking pen. The mastoid tip and suprasternal notch are used as a reference.

The skin and subcutaneous tissue are injected with 1% lidocaine with 1:100,000 epinephrine to obtain hemostasis.

The superior and inferior skin flaps are raised in a subplatysmal plane to the level of the mandibular body and the clavicle, respectively. The posterior aspect of the superior flap is raised in a plane lateral to the external jugular vein, great auricular nerve, and tail of the parotid (Figure 2-2). Medially, the skin flap is elevated slightly past the midline.

If a tracheotomy is present, care must be taken not to violate the tracheotomy incision. If this does occur, the tracheotomy incision must be separated from the remainder of the neck incision to prevent contamination with air and mucus. This is done by sewing the subcutaneous tissue surrounding the tracheotomy site to the strap muscles.

C D E

FIGURE 2–1, cont’d

Lesser occipital nerve

Greater auricular nerve

External jugular vein

A B

FIGURE 2–2

The superior and inferior skin flaps are secured to the drapes using 2-0 silk stick ties and hemostats. During the dissection, retraction of the skin flaps should occasionally be released to prevent venous congestion of the flaps.

The posterior skin flap can be elevated at this time or after the level I nodal dissection is complete. I prefer the latter.

2. DISSECTION

The superficial layer of the deep cervical fascia overlying the submandibular gland is incised 1 cm anterior and 1 cm inferior to the angle of the mandible. The marginal mandibular nerve will be found in this location. It lies lateral to the facial vessels. The nerve is sharply dissected from the underlying tissue and elevated superiorly together with the fascia (Figure 2-3). This is necessary in order to dissect the prevascular facial nodes.

An Allis clamp is placed on the fibro-fatty tissue in the midline submental area lying between the anterior bellies of the digastric muscle. This tissue is dissected in an inferior and posterior direction, exposing both anterior muscle bellies and the central portion of the mylohyoid muscle. The nerve and vessels to the mylohyoid are ligated. This tissue is left attached to the hyoid bone (Figure 2-4).