Presented at the 2012 AAPM Annual Meeting « Back

Anatomic Variation Relevant to Ultrasound-Guided Stellate Ganglion Block

Anuj Bhatia, MD FRCPC, bhatiaanuj@hotmail.com¹, David Flamer, MD¹, Philip Peng, MBBS FRCPC², (1) University of Toronto, Toronto, Ontario, Canada, (2) Department of Anesthesia, University of Toronto, Toronto, Ontario, Canada

Introduction: Stellate ganglion block (SGB) is performed using anatomic-landmark-based or fluoroscopic-guided techniques at level of the sixth cervical (C6) vertebra to provide analgesia and restore function in patients with sympathetically maintained upper extremity pain. An ultrasound (US)-guided SGB can improve efficacy and reduce complications. This study assessed variation in regional neck anatomy and analyzed two different US-guided approaches for SGB. Materials and Methods: Following protocol approval by IRB, 100 subjects ages 18–70 were enrolled. A linear probe (13-6 MHz) was used to scan regional anatomy of the neck at the levels of bilateral fifth, sixth, and seventh cervical vertebrae. Anterior and lateral approaches for needle trajectory were simulated to assess their safety and accuracy. Results: A high incidence of partial/complete lateral esophageal displacement in relation to the cricoid at the level of the C6 vertebrae was found (left: 88%, right: 2%). The distance between lateral esophageal border and medial wall of carotid artery was 9mm. Vascular analysis revealed vertebral artery entering foramen transversarium at or above level of C6 vertebra in 8% of subjects. Twenty-two percent of subjects had thyroid vessels lying in path of a simulated anterior approach for SGB. Conclusion: This study revealed significant variations in anatomy as relevant to SGB. Variable location and course of esophagus, thyroid, and vertebral vessels expose patients to risk of complications and block failure. Use of US can reduce these risks and approach can be individualized depending on the pre-block scan. References: 1)Gofeld et al. Development and validation of a new technique for ultrasound-guided stellate ganglion block. Reg Anesth Pain Med. 2009;34:475-9.

Funding: None