Overview of the Central Compartment

Overview of the Central Compartment

The central compartment is commonly referred to as level VI of the neck as described in the recent consensus update on neck dissection (4,5). The superior (hyoid) and lateral (carotid artery) central compartment boundaries are easily recognized clinically, surgically, and with current imaging modalities. The inferior border has been variably defined as the sternal notch or the innominate (brachiocephalic) artery. Use of the latter as the lower border implies inclusion of the anterior superior mediastinum above the innominate artery, sometimes referred to as level VII (4,5). The various neck levels and sublevels are presented schematically in Figure 1.

Figure 1

FIG. 1.  Schematic right anterior oblique view indicating levels of the neck and upper mediastinum relevant to neck dissection.

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The central compartment has been subdivided into right and left sides by some authors or alternatively into right, median, and left by others. These distinctions have clinical utility relevant to sided vital structures such as parathyroid glands and laryngeal nerves but are somewhat arbitrary with regard to the lymphatic drainage from central neck structures such as the thyroid gland. Indeed, the distinction between the central (level VI) and lateral cervical lymph nodes, as well as among levels I–V and sublevels Ia/Ib, IIa/IIb, and Va/Vb, is based on a premise of minimizing morbidity from injury to vital anatomic structures during compartment-oriented nodal dissection rather than a belief that lymphatic drainage observes these anatomic landmarks.