A Letter to the Editor: Impact of Neck Position on the Probability of Common Carotid Artery Puncture during Ultrasound-Guided Stellate Ganglion Block

Dear Dr. Friedly,

We commend Park and colleagues for investigating and presenting data to improve the safety of a potentially high-risk procedure^1,2. We agree that the contralateral head-turn is the optimal position when performing a stellate ganglion block under ultrasound guidance. This position improves the working space for the proceduralist, and as now shown by Park and colleagues, increases the distance from the carotid artery, reducing the risk of inadvertent vascular injury.

We note that the figures provided by Park and colleagues have mislabeled the longus capitis and longus colli muscles. This distinction is important, as the injection target is the prevertebral fascia over the longus colli, which resides posterior and medial to the longus capitis (see our modification of Park and colleagues - Figure 1B Original and Figure 1B Modified)². Their needle trajectory as shown is incorrect, as it should be steeper and directed further towards the longus colli. Of note, this would not change their measurement of distances presented, as they were calculated from C6 anterior tubercle to carotid artery. The increased depth and angulation required for the correct needle position may serve to strengthen the study’s main findings that the carotid artery distance is increased in a contralateral head position (shown in Figure 1B Modified). Their Figure 2 is correctly depicted and labeled, showing the longus colli medial to the anterior tubercle with the overlying prevertebral fascia.

Figure 1.

(B) Original Image. At the level of C6, with a short-axis view with full-contralateral neck rotation in the supine position. SCM = sternocleidomastoid muscle; PT = posterior tubercle; AT = anterior tubercle; Lc = longus colli muscle; CA = carotid artery. (B) Modified Image. Needle trajectory is now steeper and directed further toward the longus colli with the middle cervical ganglion medial to the needle tip.