Evaluation of sonoanatomy relevant to performing stellate ganglion blocks using anterior and lateral simulated approaches: an observational study

Abstract

Purpose Stellate (cervicothoracic) ganglion block (SGB) can be associated with serious complications, such as esophageal and vascular injury. The objective of this study was to evaluate the potential for vascular and esophageal injury in healthy subjects by examining the sonoanatomy of the neck relevant to the SGB at the sixth (C6) and seventh (C7) cervical vertebral levels and determining the incidence of blood vessels and esophagi in the simulated path of needle insertion in the conventional and two different ultrasound-guided approaches used to perform a SGB. Methods Ultrasound scanning of the neck at the C6 and C7 cervical vertebral levels was performed in 100 adult subjects, and the following measurements were obtained: the degree of deviation of the esophagus relative to the larynx/trachea; the likelihood of encountering a vessel in the simulated path of needle insertion in the two different approaches to SGB; the incidence of the vertebral artery being situated outside the foramen transversarium at the C6 level; and the distance of the simulated path of needle insertion in the anterior and lateral approaches to SGB at the C6 level. Results The position of the esophagus was found to be variable but lateral to the airway in 50% and 74% of the subjects at C6 and C7, respectively. The esophagus covered more than half of the distance between the airway and the carotid artery in 14% and 44% of the subjects at the C6 and C7 levels, respectively. With the anterior approach, a major vessel was observed in up to 29% and 43% of patients at the C6 and C7 levels, respectively. The vertebral artery was outside the foramen transversarium in 7% of subjects at the C6 level. Conclusion Major blood vessels and the esophagus are in close proximity to needle pathways during the anterior approach to SGB performed with either anatomic landmarking or fluoroscopic guidance. An ultrasound-guided lateral approach at the C6 level may possibly confer a greater margin of safety for performing SGB. RésuméObjectif Le bloc du ganglion stellaire (cervicothoracique) (BGS) peut eˆtre associe´a`des complications graves, telles que des le´sions oesophagiennes et vasculaires. Les objectifs de l'e´tude e´taient les suivants : e´tudier l'e´cho-anatomie du cou pertinente pour le BGS au niveau des 6 e et 7 e verte`bres cervicales (C6 et C7) chez des patients en bonne sante´, e´valuer le risque de le´sion vasculaire et oesophagienne en enregistrant l'incidence des vaisseaux sanguins et de This study was conducted with written informed consent from the study subjects. This report describes an observational clinical study, and it adheres to the STROBE guidelines.

Risk Vessels of Retropharyngeal Hematoma During Stellate Ganglion Block

“…5,6 However, identification of small vessels is often difficult, even by ultrasonography, because of the anatomical relation with the thyroid gland and the complex courses of the blood vessels. 7,8 Three-dimensional computed tomography (3D-CT) with contrast medium was recently introduced. This imaging modality allows identification of obscure blood vessels in the head and neck region.…”

Ultrasound-guided Stellate Ganglion Block

“…Although the vertebral artery enters the foramen transversarium at the level of C6 by which it is wellseparated from the stellate ganglion, anatomical variations are known to occur and in one of the studies, the vertebral artery was lying outside the foramen transversarium in up to 7% of the cases. 10 Studies have shown that injection of even a minimal dose of the local anesthetic into the vertebral artery can cause seizures as the injected local anesthetic directly reaches the brain.…”

“…The chances of encountering a major vessel is high with anterior approach at C7 level than at C6 level (29 and 43% respectively). 10 On the left side, the esophagus was located along the needle path in 39 of 60 cases at C7 level as compared to 22 of 60 cases at C6 level. 13 These above mentioned observations make the block at C6 more favorable.…”

Ultrasound-Guided Interventional Procedures for Chronic Pain Management

“…Injury to the esophagus, thyroid gland, thyroidal arteries and vertebral artery is a legitimate risk with both techniques [61,62]. US-guided SGB uses a medial or lateral approach [63]. The medial technique increases the chance of trauma to the esophagus and thyroidal arteries; therefore, we prefer a lateral in-plane approach which allows the needle to pass lateral and posterior to the carotid artery and anterior to Chassaignac's tubercle (Figure 10).…”

“…US-guided SGBs are more accurate (as determined by resultant Horner's syndrome) as compared with the landmark technique (100 vs 80-90%) [63]. Sonography is associated with fewer complications such as organ injury or Ultrasound-guided interventional procedures for chronic pain management REviEW future science group www.futuremedicine.com hematoma [61].…”