Cadaveric and ultrasonographic morphometry of cervicothoracic ganglion (Stellate ganglion)

Abstract

: Stellate ganglion block (SGB) inhibits sympathetic innervation and is a common treatment for reflex sympathetic dystrophy. During the positioning of the needle, there is a risk of injury to the adjacent structures. Cardiac sympathetic denervation (CSD) to treat ventricular arrhythmias (VAs) requires transection at the middle or lower third of stellate (cervicothoracic) ganglia (SG). However, the morphological appearance of the adult SG and its distribution are not well described. : To determine the morphology of left and right SG (LSG and RSG) and their relations with adjacent structures. 1. Cadaveric: LSG and RSG (n=30) from 15 embalmed adult cadavers were dissected intact. Weights, volume, height, morphologic appearance, relationship between C8 and T1 ganglia (which form the SG) were determined. 2. Ultra-sonographic: Fifty adult patients enrolled for other than neck pathology evaluation were included. The size, shape, the relationship between the superior pole of SG and the transverse process of C7, the relationship between the superior pole of SG and the inferior thyroid artery, and the relationships between SG and other surrounding tissues were evaluated. 1. Cadaveric part: Three distinct morphologies of SG were identified: fusiform-rounded; fusiform-elongated; and bi-lobed. RSG and LSG did not differ in weight or volume. RSG were longer than LSG. Bi-lobed morphology was most common in RSGs while fused, elongated was most common in LSG 2. Ultra-sonographic part: it was difficult to visualize SG No significant differences found in thickness and cress-sectional area on right and left side. In fact, 60% of SGs were located in the C7 transverse process level, 75% of SGs were located under the inferior thyroid artery, and all of these SGs were located lateral to the thyroid gland and medial to the anterior scalene muscle and the vagus nerve.: Knowledge of the stellate ganglia’s morphology may help for greater precision and accuracy in the transection of the lower half to distal third of the SG during stellate ganglionectomy to treat cardiac arrhythmias. Ultra-sonographic guided SGB may improve safety and allows the visualization of the local anesthetic injection site. Studying the local anesthetic spread might allow the avoidance of side effects as well as typical complications of SGB. Thus, potentially improving both the safety and efficacy of the procedure.