Anatomical and histological classification of the stellate ganglion: implications for clinical nerve blocks

The stellate ganglion (SG), or cervicothoracic ganglion, is usually located anterior to the neck of the first rib. Various techniques, such as ultrasonographic imaging and fluoroscopic approaches, are used to assist in the anesthetic blockade of the SG. However, there are reported complications associated with SG block; some patients had medication-related or systemic side effects, and some had procedure-related or local side effects. So, understanding the anatomy of the SG is critical for diagnosis and treatment of nerve block accuracy and to avoid unnecessary nerve damage during surgical procedures. This study aimed to collect data for the gross shape of the SG and histologically investigate these different types.

The SG from 31 formalin-fixed adult cadavers (59 sides) were studied. The prevalence and shape of the SG were recorded and photographed. Next, the SG for each type was examined histologically.

The SG were classified into four types based on their shape: dumbbell, spindle, star, and inverted L shapes. The frequency of each type was as follows: spindle (47.46%), dumbbell (27.12%), star (23.73%), and L-inverted shapes (1.69%). Each type had a similar number of nerve cell bodies. Interestingly, the inverted-L shaped SG was histologically, discontinuous but grossly fused.

An improved understanding of the SG's macro and microanatomy can help better understand patient presentations and improve clinical and surgical results in procedures performed near this important neck structure.