1957 – Hayes Martin describes routine use of the radical neck dissection for control of neck metastases.
1967 – Oscar Suarez and E. Bocca describe a more conservative operation that preserves SAN, IJV and SCM.
Last 3 decades – Further operations have been described to selectively remove the involved regional lymph groups.
Division of the Neck into Levels and Sublevels
To describe the lymph nodes of the neck for neck dissection, the neck is divided into 6 areas called Levels. The levels are identified by Roman numeral, increasing towards the chest. A further Level VII to denote lymph node groups in the superior mediastinum is no longer used. Instead, lymph nodes in other non-neck regions are referred to by the name of their specific nodal groups.
Level II – This includes lymph nodes of the upper jugular group and is divided into sublevels IIA and IIB.
:Level II is bounded by the inferior border of the hyoid, the base of skull, the stylohyoid muscle and the posterior border of the SCM. Sublevel IIA nodes lie anterior to the SAN. Sublevel IIB nodes lie posterior to the SAN.
Level III – This includes lymph nodes of the middle jugular group.
:This level is bounded by the inferior border of the hyoid and the inferior border of the cricoid, the posterior border of the sternohyoid and the posterior border of the SCM.
Level IV – This includes lymph nodes of the lower jugular group.
:This level is bounded by the inferior border of the cricoid, the clavicle / sternal notch, the posterior border of the sternohyoid and the posterior border of the SCM.
Level V – This includes posterior compartment lymph nodes.
:This compartment is bounded by the clavicle, the anterior border of the trapezius, the posterior border of the SCM. It is divided into sublevels VA and VB.
Level VI – This includes the anterior compartment lymph nodes.
Radical Neck Dissection – removal of all ipsilateralcervical lymph node groups from levels I through V, together with SAN, SCM and IJV.
Modified Radical Neck Dissection – removal of all lymph node groups routinely removed in a RND, but with preservation of one or more nonlymphatic structures.
Selective Neck Dissection – cervical lymphadenectomy with preservation of one or more lymph node groups that are routinely removed in a RND. Thus for oral cavity cancers, SND is commonly performed. For oropharyngeal, hypopharyngeal and laryngeal cancers, SND is the procedure of choice.
Extended Neck Dissection. This refers to removal of one or more additional lymph node groups or nonlymphatic structures, or both, not encompassed by the RND.
