Neck dissection, also known as cervical lymphadenectomy, is the surgical procedure for the management of metastatic cervical lymphadenopathy. There are multiple types of neck dissection that vary by the structures removed ¹. This article reflects the 2001 classification by the American Head and Neck Society and the American Academy of Otolaryngology-Head and Neck Surgery ^1,2.

Terminology

It is worth noting that although the classification presented here, based on that proposed by the American Academy of Otolaryngology-Head and Neck Surgery is most widely used, other terminology is encountered. Alternative terms generally similar to radical neck dissection include: comprehensive neck dissection, complete functional neck dissection, full neck dissection, total neck dissection and many other variants ^3,4.

Classification

Radical neck dissection

Radical neck dissection is the historical standard by which subsequent approaches are compared and defined. The radical neck dissection involves removal of all ipsilateral cervical lymph nodes from levels I through V, as well as the submandibular gland.

Three key extranodal structures are also removed:

• spinal accessory nerve

• sternocleidomastoid muscle

• internal jugular vein (IJV)

Modified radical neck dissection

Modified radical neck dissection involves removal of cervical nodes, levels I through V, as in classical radical neck dissection, but with preservation of one or more of the key extranodal structures (spinal accessory nerve, sternocleidomastoid muscle, and internal jugular vein). Although previously grouped by types (I through III), variation in practice makes it advisable to name explicitly the structures spared in a modified radical neck dissection (e.g. modified radical neck dissection with preservation of the spinal accessory nerve).

Selective neck dissection

Selective neck dissection (SND) involves removal of some but not all of the cervical lymph node groups removed in the radical neck dissection.

Historically, there were named subtypes of selective neck dissections:

• supraomohyoid: levels I-III

  • extended supraomohyoid (anterolateral): levels I-IV

• posterolateral: levels II-V, suboccipital, postauricular

• lateral (jugular): levels II-IV

• anterior (central): level VI

Due to evolving practices, the 2001 classification omitted the named subtypes in favor of precise description with "SND" and parentheses denoting the levels removed, e.g. SND (I-IV).

The cervical lymph nodes groups/levels typically removed depends on expected patterns of metastatic spread from a given primary site ²:

• oral cavity: levels I-III

  • some surgeons also include some or all of level IV

• oropharynx, hypopharynx, larynx: levels II-IV

  • excluding level IIB in some cases of laryngeal or hypopharyngeal cancer

  • plus retropharyngeal nodes if the primary lesion involves the pharyngeal wall

  • plus level VI if the primary lesion extends below the glottis level

  • plus superior mediastinal nodes if the primary lesion extends below the suprasternal notch level

• thyroid: level VI

• skin of posterior scalp and upper neck: levels II-V, suboccipital, postauricular

• skin of preauricular, anterior scalp, temporal region: levels II-III, level VA, parotid, facial, external jugular

• skin of anterior and lateral face: levels I-III, parotid, facial

Dissections are performed bilaterally if the primary lesion crosses the midline.

Extended radical neck dissection

Extended radical neck dissection involves removal of levels I through V and key non-nodal structures (spinal accessory nerve, sternocleidomastoid muscle, and internal jugular vein), as in classical radical neck dissection, but with removal of one or more additional lymph node groups and/or non-lymphatic structures.

Such nodal groups include:

• suboccipital nodes

• retropharyngeal nodes

• parotid nodes

• facial nodes (e.g. buccinator nodes)

• level VI (e.g. paratracheal nodes, Delphian node, perithyroidal nodes)

• superior mediastinal nodes

Possible non-lymphatic structures include:

• carotid artery

• hypoglossal nerve

• vagus nerve

• paraspinal muscles