On one side it is bounded by the prevertebral fascia.

[1] On the other side, some sources define it as bounded by the vertebral bodies,[2] and others define it as bounded by the longus colli.

[1] It includes the prevertebral muscles (longus colli and longus capitis), vertebral artery, vertebral vein, scalene muscles, phrenic nerve and part of the brachial plexus.

[3] In trauma, an increased thickness of the prevertebral space is a sign of injury, and can be measured with medical imaging.

Causes of enlarged prevertebral space could be edema, hematoma, abscess, tumors, and post surgical changes.