Retropharyngeal space

The retropharyngeal space is one of the most clinically important deep fascial spaces of the neck.

Location and extent

It is a potential space situated posterior to the pharynx and esophagus and anterior to the prevertebral muscles and fascia, extending from the base of the skull to the upper mediastinum. Anteriorly, it is bounded by the buccopharyngeal fascia, posteriorly by the alar fascia, and laterally by the carotid sheaths.

Sub-divisions of retropharyngeal space

The retropharyngeal space is divided by the alar fascia into two distinct compartments: the true retropharyngeal space anteriorly and the danger space posteriorly. The danger space extends inferiorly through the thorax to the diaphragm, providing a potential route for the spread of infection from the neck into the posterior mediastinum.

The termination of the true retropharyngeal space along the upper thoracic spine (T1-T6) is variable based on where the alar fascia joins and fuses with the visceral fascia.

Functions

The retropharyngeal space allows movement of the pharynx, larynx, and oesophagus during swallowing and neck movements.

It is subdivided into suprahyoid and infrahyoid portions. The suprahyoid part contains loose areolar tissue and the retropharyngeal lymph nodes, whereas the infrahyoid part contains mainly adipose tissue.

Retropharyngeal lymph nodes

The retropharyngeal lymph nodes lie medial to the internal carotid artery and are divided into medial and lateral groups. The medial group normally involutes during childhood, whereas the lateral group, known as the nodes of Rouvière, persists into adulthood and may serve as a site of metastatic spread from head and neck malignancies. These lymph nodes are responsible for draining much of the pharynx, nasopharynx, adenoids, posterior nasal cavity, paranasal sinuses, and middle ear.

Clinical correlate

The retropharyngeal space is a major route for the spread of deep neck infections. Because the retropharyngeal space communicates with the danger space and mediastinum, infection may spread inferiorly, leading to potentially lifethreatening complications such as descending necrotising mediastinitis, empyema, sepsis, and airway obstruction.

Summary

Remember that the retropharyngeal space lies between the buccopharyngeal fascia and alar fascia, contains the retropharyngeal lymph nodes (including the nodes of Rouvière), extends from the skull base to the upper mediastinum, and is separated from the posteriorly located danger space by the alar fascia. Its clinical importance lies in its role as a major pathway for the spread of infection from the pharynx to the mediastinum.