Variations in the distance between the cricoid cartilage and targets of stellate ganglion block in neutral and extended supine positions: an ultrasonographic evaluation.

C6TP and C7TP are located approximately 15 and 25 mm, respectively, caudal to the cricoid cartilage in the extended supine position. Our results highlight the fact that there can be significant anatomic variation between the extended and neutral supine positions used in stellate ganglion block, which should be kept in mind when devising easily identifiable and palpable surface landmarks.