Review of Sympathetic Blocks

Abstract

The autonomic nervous system is composed of the sympathetic and parasympathetic nervous systems. The sympathetic nervous system is implicated in situations involving emergent action by the body and additionally plays a role in mediating pain states and pathologies in the body. Painful conditions thought to have a sympathetically mediated component may respond to blockade of the corresponding sympathetic fibers. The paravertebral sympathetic chain has been targeted for various painful conditions. Although initially injected using landmark-based techniques, fluoroscopy and more recently ultrasound imaging have allowed greater visualization and facilitated injections of these structures. In addition to treating painful conditions, sympathetic blockade has been used to improve perfusion, treat angina, and even suppress posttraumatic stress disorder symptoms. This review explores the anatomy, sonoanatomy, and evidence supporting these injections and focuses on ultrasound-guided/assisted technique for the performance of these blocks.

Subfascial versus extrafascial ultrasound-guided stellate ganglion block in patients with post-mastectomy sympathetically mediated pain: A randomized clinical trial

“…21 Interpatient variation means the stellate ganglion is fused with the first thoracic ganglia in up to 80% of the population, meaning that for the majority of patients, the spread of local anaesthetic down to the level of T2 is needed to achieve a successful block. 22…”

“…21 Interpatient variation means the stellate ganglion is fused with the first thoracic ganglia in up to 80% of the population, meaning that for the majority of patients, the spread of local anaesthetic down to the level of T2 is needed to achieve a successful block. 22 Of note, the traditional landmark guided, paratracheal method of SGB is performed at the site of C6. This approach has been described as suboptimal, due to the risk of damage imposed by the manual pressure needed to displace the thyroid and carotid artery to create a passageway for injection.…”

<p>Ultrasound-Guided Thoracic Paravertebral Block as a Sympathetic Blockade for Upper Extremity Neuropathic Pain: A Prospective Pilot Study</p>

“…In order to perform a sympathetic blockade of the upper extremity, US-guided SGB or FS-guided TSGB has been mainly implemented. 34,35 However, SGB is incomplete due to Kuntz bypass 36,37 and TSGB has a higher risk of pneumothorax because the needle should reach the anterior paravertebral space (Figure 4). 10,20 For this reason, TSGB usually requires FS guidance.…”

Bi-national survey of Korea and Japan related to the injection site for ultrasound-guided stellate ganglion blocks and anatomic comparisons using cadaver dissection

“…An accurate knowledge of anatomy is also essential to performing safe and effective blockades, and so the exact positions of the cervical sympathetic trunk and stellate ganglion have always been of considerable interest to interventional pain physicians. However, topographic descriptions of the cervical sympathetic trunk have been reported differently according to the literature [11][12][13].…”