Carotid Artery Tortuosity With a Vertebral Artery Entering the Transverse Foramen at an Atypical Level: A Cadaveric Case Underlining the Need for Thorough Anatomical Assessment Before a Stellate Ganglion Block.

A stellate ganglion block (SGB) is a therapeutic procedure that transiently interrupts the cervical sympathetic trunk using a local anesthetic, applied not only for pain management but also for conditions such as facial nerve palsy, sudden sensorineural hearing loss, hyperhidrosis, post-traumatic stress disorder, and certain cardiac arrhythmias. The widespread adoption of ultrasound guidance has improved both the safety and the precision of SGB. During cadaveric dissection at Teikyo University School of Medicine in 2024, a rare coexistence of right common carotid artery (RCCA) tortuosity and a high-rising right vertebral artery (RVA) was identified in an 86-year-old female. The RVA ascended superior to the upper margin of the thyroid gland and likely entered the transverse foramen at C4-C5, in contrast to the left vertebral artery, which entered at the typical C6 level. This previously unreported combination of vascular anomalies underscores the diversity of cervical vascular anatomy and highlights potential risks during neck procedures, including SGB, tracheostomy, thyroid surgery, and anterior cervical spine interventions. Pre-procedural ultrasound provides a noninvasive and cost-effective method for mapping vascular structures; however, its effectiveness depends on the clinician's anatomical expertise and interpretive accuracy. This case emphasizes the importance of integrating detailed anatomical knowledge with ultrasound assessment to enhance procedural safety and prevent iatrogenic complications.