The flattest and most echogenic part of the articular pillar is identified in the axial plane.

Place the patient in the lateral decubitus position.

Place a curved array probe in the parasagittal plane and identify the superior margin of the sacrum and the transverse process of vertebra L5. Move the probe cranially while counting the transverse processes. At the target level, the probe is rotated to the axial plane and the spinous process, the articular process and the transverse process are identified.

The needle is inserted from the lateral end of the probe aiming at the groove between the superior margin of the transverse process and the superior articular proces until bony contact.

Inject 1 mL of local anaesthetic.

Place the patient sitting.

Place the linear high-frequency probe in the axial plane and identify the transverse proces of vertebra C7 – the only transverse process with no anterior tubercle

Make a parallel shift cranially while counting the transverse processes until the desired level is reached

Identify the deepest concavity of the articular pillar as the most flat and echogenic part of the articular pillar (see next page)

Check for blood vessels with color Doppler

Insert the needle in-plane from the posterior end of the probe until the needle tip touches the deepest concavity of the articular pillar.

Inject 0.5 mL of local anaesthetic.

The medial branches of the lumbar dorsal spinal rami cross the cranial margin of the transverse processes and the groove where the cranial margin of the transverse process is adjacent to the superior articular process.

The cervical medial branches from the dorsal spinal rami follow the deepest concavity of the articular pillars of the cervical vertebrae.

At the level of the Chassaignac’s tubercle (the anterior tubercle of transverse process of vertebra C6) the sympathetic trunk is typically enclosed by split layers of the prevertebral fascia. It is not possible to visualize the sympathetic trunk sonographically. Local anaesthetic should be deposited on both sides of the prevertebral fascia.

Gray rami contain postganglionic sympathetic fibres from each ganglion of the sympathetic trunk to the adjacent spinal nerves (somatic fibre) or to internal organs (visceral fibres – only in some cervical and thoracic segments). In the cervical spine region, the gray rami penetrate the prevertebral layer of the deep cervical fascia and also the longus colli muscle on their way to the spinal nerves of the brachial plexus.

White rami are only present from T1-L2. I.e. they are not present in the cervical spine segment. They contain efferent preganglionic sympathetic fibres from the ipsilateral intermediolateral cell column (only present from T1-L2) of the spinal cord. These preganglionic fibres synapse with ganglia of the sympathetic trunk either at the same level or ascend or descend within the sympathetic trunk before they synapse. The white rami also contain afferent sympathetic fibres from the cell bodies in the dorsal root ganglia.

The stellate ganglion is part of the sympathetic trunk. At the level of the transverse process of the C6 vertebral body, the sympathetic trunk runs in a cleavage of the prevertebral layer of the deep cervical fascia (between the deep cervical fascia proper and the alar fascia), medial to the carotid sheath (that contains the common carotid artery, the internal jugular vein and the vagus nerve (X)), and anterior to the colli longus muscle.

Diagnostic procedure to test whether the medial branches mediate spinal pain

Usually performed with fluoroscopy

Ultrasound guidance is a reliable alternative to fluoroscopy

Kapral S et al: Ultrasound imaging for stellate ganglion block: Direct visualization of puncture site and local anesthetic spread. Regional anesthesia 20(4): 323-328 (1995)