Impact of Neck Position on the Probability of Common Carotid Artery Puncture During Ultrasound-Guided Stellate Ganglion Block

Background: The carotid artery must be avoided during stellate ganglion block. However, information on optimal neck position during the ultrasound-guided approach is limited. Objective: To investigate the relation between the target area of the procedure and the carotid artery in different neck positions. Design: Observational study. Setting: Tertiary university. Participants: A total of 30 sides of the neck from 18 healthy participants were included. Methods: An ultrasound transducer was placed at the level of the anterior tubercle of C6 with a short-axis view for measuring the distance from the tip of the C6 anterior tubercle to the margin of the carotid artery. The participants were first examined through ultrasonography in 3 different rotational neck positions (neutral, semicontralateral rotation, and full-contralateral rotation), in the supine position. After changing to the lateral decubitus position, the measurement was performed again in the same 3 neck positions. Main Outcome Measures: The C6 anterior tubercle to carotid distance was measured with ultrasound. Results: The C6 anterior tubercle to carotid distance was the longest with full-contralateral neck rotation (P <.05). The distance was longer in the semicontralateral neck rotation compared with the neutral neck position (P <.05). Supine or decubitus positions did not affect the distance. Conclusions: We suggest that the full-contralateral neck rotation posture in either the supine or decubitus position is most beneficial for avoiding damage to the carotid artery during the ultrasound-guided stellate ganglion block. Level of Evidence: Not applicable.