I. GENERAL CONSIDERATIONS

A. Indications

Elective treatment of N₀ neck with significant risk of regional metastasis. See Table IIIE-1 (PDF) and Cervical Lymphadenectomy: General Considerations Treatment of selected N₁ neck disease

B. Contraindications

1. Extensive neck disease (greater than N₁)

2. Evidence of extracapsular spread by clinical or radiographic evaluation (ie, fixed nodes, involvement of deep neck muscles, cranial nerves, sternocleidomastoid muscle, internal jugular vein, carotid artery

C. Extent of Neck Dissection

The selection of which levels of lymph nodes require removal depends on the location of the primary tumor and the predicted spread of local disease to regional sites (See Table IIIE-1 (PDF))

II. PREOPERATIVE PREPARATION

A. Additional Preoperative Evaluations

CT scan of neck

B. Consent Inclusions

Same as modified radical neck dissection (see Radical neck dissection protocol)

III. NURSING CONSIDERATIONS

Same as modified radical neck dissection (see Radical neck dissection protocol)

IV. ANESTHESIA CONSIDERATIONS

Same as modified radical neck dissection (see Radical neck dissection protocol)

V. OPERATIVE PROCEDURE

A. Pertinent Anatomy

Identify the angle and body of the mandible, mastoid tip, midline of the neck, clavicle, and sternocleidomastoid muscle

B. Incisions

Utility incision from mastoid tip into a transverse lower neck skin crease is used most commonly. A posterior limb may be dropped if access to Level IV is difficult.

C. Skin Flap Elevation

1. Standard subplatysmal flap elevation leaving superficial veins and fascia of the SCM muscle down. The great auricular nerve may be preserved. If a tracheotomy has been performed, every attempt is made to keep the neck dissection separate from the tracheotomy site. If communication between the neck dissection and tracheotomy site occurs, it is closed in an airtight fashion to prevent an air leak from the suction drains.

2. Limits of elevation

a. Superior: mandible, mastoid tip, and parotid gland

b. Inferior: clavicle

c. Anterior: anterior border of sternohyoid muscle

d. Posterior: posterior border of sternocleidomastoid muscle

D. Dissection

1. Level I (submandibular and submental dissection)

a. If perifacial lymph nodes do not require removal, the superior skin flap is raised to the inferior aspect of the submandibular gland. The fascia over the gland is incised, and the posterior facial vein is ligated and divided. Both are elevated off the gland. This maneuver protects the marginal mandibular nerve from injury. The fascia is elevated to the inferior border of the mandible, and its attachments to the mandible are divided. The facial artery and vein are ligated and divided.

b. The contralateral anterior belly of the digastric muscle is defined, and the superficial fat over the anterior bellies of both digastric muscles (submental fat) is dissected in a lateral direction. The dissection is continued laterally over the ipsilateral mylohyoid muscle, which is then retracted with an Army-Navy retractor anterosuperiorly. The submandibular gland is then retracted inferiorly. The submandibular fat and lymph nodes may be swept inferiorly with a sponge. The lingual nerve and submandibular ganglion are identified. The submandibular ganglion and duct are ligated and divided. The contents of the submandibular triangle are dissected in a medial to lateral direction. The facial artery is divided a second time at the posterior aspect of the gland. The specimen is rolled off the posterior belly of the digastric muscle and kept pedicled to the Level II neck contents.

c. If the perifacial lymph nodes require removal, the superior subplatysmal flap is carefully raised with cold blunt or sharp dissection. The marginal mandibular branch of the facial nerve can be identified running just below the angle of the mandible proximally and superficial to the posterior facial vein and within the submandibular fascia in its middle portion before turning superiorly to the lower lip. The facial nerve stimulator may be used to help identify and confirm the integrity of the marginal mandibular nerve. Once identified, the nerve is carefully elevated off the underlying soft tissue with the subplatysmal flap. The remaining portion of the dissection proceeds as described above.

2. Jugular chain dissection (Levels II-IV)

a. The fascia over the sternocleidomastoid muscle is divided along its length. The fascia is elevated in a medial direction using a #15 blade scalpel. This dissection is facilitated by having an assistant retract the medial aspect of the incised fascia with Allis clamps or with digital pressure employing a sponge. The surgeon can apply counter retraction on the muscle using a sponge in one hand while dissecting with a #15 blade in the other hand.

b. The spinal accessory nerve is identified running over the lateral process of C2, posterolateral to the internal jugular vein and into the medial aspect of the SCM muscle. The spinal accessory nerve is skeletonized from the surrounding soft tissue from the skull base to the SCM. If Level IIA (supraspinal compartment) is to be removed, the fatty tissue deep to the superior portion of the sternocleidomastoid muscle and overlying the deep neck musculature is sharply divided off the deep neck musculature fascial “carpet” and pulled under the spinal accessory nerve. In this manner, Level IIA remains in continuity with the remaining neck specimen. The occipital artery is usually encountered and ligated during this dissection.

c. Once the SCM fascia has been elevated off the medial aspect of the muscle, the fascia and fat posterior to the internal jugular vein can be divided down the deep neck muscular fascial carpet. Arbitrarily establishing the posterior limit of Levels II, III, and IV as 2 cm posterior to the internal jugular vein ensures that the dissection is adequate to remove all of these levels (and some of Level V). The cervical rootlets are skeletonized as the fat and fascia are dissected anteriorly toward the internal jugular vein.

d. The specimen is elevated superior to the fascial carpet using a #15 blade, sparing the cervical rootlets, brachial plexus, and phrenic nerve. Medial retraction of the specimen by an assistant is helpful in accomplishing this task. As the specimen is rolled out medially, the vagus nerve and carotid artery are identified first and preserved. The specimen is then sharply divided off of the internal jugular vein just superficial to the adventitia. The omohyoid muscle is usually preserved but may be sacrificed if exposure of Level IV is difficult.

e. The specimen is then dissected away from the sternohyoid muscles inferiorly and off the hypoglossal nerve, branches of the internal jugular vein, and external carotid artery superiorly.

f. If free tissue transfer is required for reconstruction of a primary defect, the internal jugular vein branches and external carotid artery branches should be handled with extreme care to avoid intimal damage. Ligation of these vessels should be performed as distal as possible to optimize vascular pedicle geometry.

g. Following removal of the specimen, Level IV is inspected for a chyle leak. This is particularly important in a left neck dissection. Positive airway pressure applied by the anesthesiologist may aid in detection of a chyle leak. If a leak is detected, it is carefully ligated with a 3-0 silk suture. Closure of the leak must be ensured prior to closure of the neck.

h. The neck specimen is then divided into its component levels (ie, I, IIa, IIb, III, IV) on a back table and sent to pathology in separate containers.

E. Closure

Skin flaps are closed in 2 layers

1. Platysma/subcutaneous layer with 3-0 vicryl

2. Skin with surgical clips, 4-0 or 5-0 nylon

F. Drains

At least two fully perforated, 10 mm Jackson-Pratt drains are placed

1. Deep to the sternocleidomastoid muscle and posterior to the internal jugular vein and spinal accessory nerve

2. Anteriorly over the sternocleidomastoid muscle into Level I

3. Drains are attached to Varidyne pumps set for continuous suction at 125 cm H₂O. Suction is initiated immediately following drain placement to prevent clotting of the drain.

G. Dressing

Bacitracin ointment to skin incision

VI. POSTOPERATIVE CARE

Same as for Modified radical neck dissection protocol

VII. CPT CODING

A. 38700, Suprahyoid neck dissection (Level I)

B. 38724, Selective neck dissection (any combination of Levels I-IV)