Cross-sectional anatomy

Cross-sectional anatomy

Cranial to C4, the cervical plexus is located within the prevertebral layer of deep cervical fascia in a groove between the longus capitis and the middle scalene muscle. At the level of C4- C5, the plexus is located superficial to the prevertebral fascia overlying the interscalene groove, immediately deep to the sternocleidomastoid muscle (SCM). 

Deep injection technique: Local anesthetic can be deposited at the C2-C4 paravertebral space, deep to the prevertebral fascia; this blocks the entire plexus (high risk for complications).

Intermediate injection technique: Local anesthetic is injected at the level of the transverse process of C4, between the prevertebral fascia and the investing layer of the deep cervical fascia.

Superficial injection technique: At the level of C6, the local anesthetic is injected subcutaneously and superficially to the deep cervical fascia to block all or specific cutaneous branches.

Cervical plexus (transverse view at the level of C4 and C6). Injection site for superficial, intermediate, and deep cervical plexus blocks.

Cervical plexus transverse view at the level of C4 and C6.