An anatomy-first synthesis linking classical dissection, high-resolution MRI, histology, anatomical variation, and the expanding clinical use of stellate ganglion block.
The paper identifies the SG by a reproducible three-dimensional neighbourhood: anterior to the neck of the first rib, lateral to the longus colli muscle, and posterior to the vertebral artery.
The clinical label often implies a single star-shaped ganglion. Anatomically, the lower cervical sympathetic chain can instead show incomplete fusion, intermediate/vertebral ganglia, variable ansa subclavia, and accessory pathways.
Inferior cervical and first thoracic ganglia form the SG in approximately four of five individuals.
Spindle, dumbbell, truncated, perforated, and inverted-L morphologies are reported in dissection studies.
Published incidence varies widely across anatomical studies.
Click each landmark to see why it helps identify—and safely approach—the ganglion.
The review includes original 1.5-T MRI material rather than relying only on historical cadaveric descriptions.
Siemens Magnetom Avanto.
TR 550 ms · TE 12 ms.
Inter-slice gap 0.3 mm.
FOV 300 mm.
Several structures can change the location, shape, or accessibility of the lower cervical sympathetic system.
May lie superior to the SG around the pre-foraminal vertebral artery and can be prominent when the SG itself is small.
Short and long loops can connect the lower cervical sympathetic ganglia around the subclavian artery.
Accessory sympathetic pathways can bypass the expected chain anatomy and help explain incomplete sympathetic blockade.
The SG is usually precostal but may be more cervical/supracostal or descend behind the pleura toward the second rib.
Vertebral, inferior thyroid, ascending/deep cervical, carotid, and subclavian vessels alter needle corridors and risk.
The paper's axial MRI series emphasises that left/right vascular topography at C6–T1 is not necessarily mirror-symmetric.
The review discusses reported applications of stellate ganglion block while emphasising image guidance and the structures at risk.
Cardiac arrhythmias, chronic pain syndromes, PTSD, sleep disorders, postoperative recovery, and neuroimmune modulation.
Vertebral and other cervical arteries, internal jugular vein, pleura, recurrent laryngeal nerve, and phrenic nerve.
Because true fusion is not universal, “lower cervical sympathetic block” may sometimes be anatomically more precise than the conventional label “stellate ganglion block”.