Classification of Neck Dissections
Radical neck dissection
Refers to the removal of all lymph node groups extending from the inferior border of the mandible superiorly to the clavicle inferiorly, from the lateral border of the sternohyoid muscle, hyoid bone, and contralateral anterior belly of the digastric muscle medially, to the anterior border of the trapezius muscle laterally. Included are all lymph nodes from levels I-V with sacrifice of internal jugular vein, sternocleidomastoid muscle, and spinal accessory nerve.
Extended Radical Neck Dissection
Refers to the removal of one or more additional lymph node groups or non-lymphatic structures or both, not encompassed by the radical neck dissection.
Modified radical neck dissection
Refers to the removal of all lymph nodes by radical neck dissection with preservation of one or more of the non-lymphatic structures: i.e., the spinal accessory nerve, internal jugular vein and the sternocleidomastoid muscle.
Selective neck dissection
Refers to any type of cervical lymphadenectomy where there is preservation of one or more of the lymph node groups removed by the radical neck dissection. The types of selective dissections are described below.
Supraomohyoid Neck Dissection
Refers to the removal of lymph nodes contained in levels I-III. The posterior limit of the dissection is marked by the cutaneous branches of the cervical plexus and the posterior border of the sternocleidomastoid muscle. The inferior limit is the superior belly of the omohyoid muscle where it crosses the internal jugular vein.
Extended Supraomohyoid Neck Dissection
Adds level IV nodes as well as the nodes in Level V superior to the inferior belly of the omohyoid.
Posterolateral Neck Dissection
Refers to removal of the suboccipital lymph nodes, retroauricular lymph nodes and lymph nodes in levels II-V. Basically, all nodal groups except levels IA and IB.
Lateral Neck Dissection
Refers to the removal of lymph nodes in levels II-IV, along the internal jugular vein. Excludes nodes in Level IA, IB and V.
Central Compartment Neck Dissection
Refers to the bilateral removal of lymph nodes surrounding the midline visceral structures of the anterior neck - level VI. The lymph nodes include the pre- and paratracheal, pre-cricoid (Delphian) and perithyroidal. The superior limit of the dissection is the hyoid bone; the inferior limit is the suprasternal notch; and the lateral limits are the carotid arteries.