Spinal Accessory Nerve: Ultrasound Findings and Correlations with Neck Lymph Node Levels

Abstract

Purpose: To evaluate the ultrasound characteristics of the spinal accessory nerve (SAN) and correlate nerve location with neck lymph node level.

Materials and Methods: 50 participants with 100 SANs were enrolled in this study. The SAN was traced from the trapezius muscle to the upper neck and was identified by a hypoechoic linear structure without color Doppler flow. The ultrasound characteristics of the SAN, such as visibility, diameter, relationship with adjacent structures, and its correlation with lymph node levels, were evaluated.

Results: The SAN was identified in 96 %-100 % of segments. The mean diameter of the SAN was 0.54 ± 0.09 mm. The SANs was located between the trapezius and levator scapulae muscles and 90.8 % were traced into the trapezius muscle. In the upper neck, the SAN passed deep into the sternocleidomastoid (SCM) muscle in 38 % of cases and between the two heads of the SCM muscle in 62 % of cases. The SAN was found at neck lymph node levels II, III, IV, and V, but not I or VI.

Conclusion: Continuous ultrasound monitoring of the SAN and its correlation with lymph node levels is possible in most patients. Our current findings may assist in the future prevention of SAN injury during ultrasound-guided procedures.

Zusammenfassung

Ziel: Bewertung der sonografischen Charakteristika des Nervus accessorius (SAN) und die Korrelation zwischen der Lage des Nervs und der Ebene der Halslymphknoten.

Material und Methoden: In diese Studie wurden fünfzig Teilnehmer mit 100 SANs aufgenommen. Der SAN wurde vom Musculus trapezius bis zum oberen Hals ausfindig gemacht und als echoarme lineare Struktur ohne Farbdopplerfluss identifiziert. Die Ultraschalleigenschaften des SAN wie Sichtbarkeit, Durchmesser, Beziehung zu den umgebenden Strukturen und dessen Beziehung mit der Ebene der Lymphknoten wurde bewertet.

Ergebnisse: Der SAN wurde in 96 – 100 % der Segmente nachgewiesen. Der mittlere Durchmesser des SAN betrug 0,54 ± 0,09 mm. Die SAN befanden sich zwischen dem M. trapezius und dem M. levator scapulae und 90,8 % wurden im M. trapezius ausfindig gemacht. Im oberen Hals verlief in 38 % der Fälle der SAN tief in den M. sternocleidomastoideus (SCM) hinein und bei 62 % zwischen den beiden Köpfen des SCM. Der SAN wurde bei den Halslymphknoten II, III, IV und V, jedoch nicht bei I oder VI entdeckt.

Schlussfolgerung: Eine fortlaufende sonografische Überwachung des SAN und dessen Beziehung zur Ebene der Halslymphknoten ist bei den meisten Patienten möglich. Unsere aktuellen Befunde könnten dazu beitragen, Verletzungen des SAN bei ultraschallgestützten Prozessen in Zukunft zu verhindern.

Key words

ultrasound - anatomy - thyroid

• References

• 1 Bostrom D, Dahlin LB. Iatrogenic injury to the accessory nerve. Scand J Plast Reconstr Surg Hand Surg 2007; 41: 82-87
• 2 London J, London NJ, Kay SP. Iatrogenic accessory nerve injury. Ann R Coll Surg Engl 1996; 78: 146-150
• 3 Morris LG, Ziff DJ, DeLacure MD. Malpractice litigation after surgical injury of the spinal accessory nerve: an evidence-based analysis. Arch Otolaryngol Head Neck Surg 2008; 134: 102-107
• 4 Durazzo MD, Furlan JC, Teixeira GV et al. Anatomic landmarks for localization of the spinal accessory nerve. Clin Anat 2009; 22: 471-475
• 5 Dailiana ZH, Mehdian H, Gilbert A. Surgical anatomy of spinal accessory nerve: is trapezius functional deficit inevitable after division of the nerve?. J Hand Surg Br 2001; 26: 137-141
• 6 Hone SW, Ridha H, Rowley H et al. Surgical landmarks of the spinal accessory nerve in modified radical neck dissection. Clin Otolaryngol Allied Sci 2001; 26: 16-18
• 7 Shin JE, Baek JH, Lee JH. Radiofrequency and ethanol ablation for the treatment of recurrent thyroid cancers: current status and challenges. Curr Opin Oncol 2013; 25: 14-19
• 8 Kraft M, Gurtler N, Schmuziger N et al. Ultrasound-guided core-needle biopsy in the diagnosis of head and neck lesions. J Laryngol Otol 2007; 121: 895-896
• 9 Kim BM, Kim EK, Kim MJ et al. Sonographically guided core needle biopsy of cervical lymphadenopathy in patients without known malignancy. J Ultrasound Med 2007; 26: 585-591
• 10 Screaton NJ, Berman LH, Grant JW. Head and neck lymphadenopathy: evaluation with US-guided cutting-needle biopsy. Radiology 2002; 224: 75-81
• 11 Yamashita Y, Kurokawa H, Takeda S et al. Preoperative histologic assessment of head and neck lesions using cutting needle biopsy. Oral Surg Oral Med Oral Pathol Oral Radiol Endod 2002; 93: 528-533
• 12 Ridder GJ, Pfeiffer J. Usefulness of cutting needle biopsy in recurrent and advanced staged head and neck malignancies in a palliative setting. Support Care Cancer 2007; 15: 1301-1307
• 13 Baek JH, Kim YS, Sung JY et al. Locoregional control of metastatic well-differentiated thyroid cancer by ultrasound-guided radiofrequency ablation. Am J Roentgenol Am J Roentgenol 2011; 197: W331-W336
• 14 Bodner G, Harpf C, Gardetto A et al. Ultrasonography of the accessory nerve: normal and pathologic findings in cadavers and patients with iatrogenic accessory nerve palsy. J Ultrasound Med 2002; 21: 1159-1163
• 15 Nason RW, Abdulrauf BM, Stranc MF. The anatomy of the accessory nerve and cervical lymph node biopsy. Am J Surg 2000; 180: 241-243
• 16 Valtonen EJ, Lilius HG. Late sequelae of iatrogenic spinal accessory nerve injury. Acta Chir Scand 1974; 140: 453-455
• 17 Fellmer PT, Fellmer J, Jonas S. Injury to the Spinal Accessory Nerve during Lymph Node biopsy: Expert Witnesses and Evidence-Based Procedures. Zentralbl Chir 2013; DOI: 10.1055/s-0032-1327889:.
• 18 Canella C, Demondion X, Abreu E et al. Anatomical study of spinal accessory nerve using ultrasonography. Eur J Radiol 2013; 82: 56-61
• 19 Mirjalili SA, Muirhead JC, Stringer MD. Ultrasound visualization of the spinal accessory nerve in vivo. J Surg Res 2012; 175: e11-e16
• 20 Ha EJ, Baek JH, Lee JH et al. Characteristic ultrasound feature of traumatic neuromas after neck dissection: direct continuity with the cervical plexus. Thyroid 2012; 22: 820-826
• 21 Ha EJ, Baek JH, Lee JH et al. Clinical significance of vagus nerve variation in radiofrequency ablation of thyroid nodules. Eur Radiol 2011; 21: 2151-2157
• 22 Som PM, Curtin HD, Mancuso AA. Imaging-based nodal classification for evaluation of neck metastatic adenopathy. Am J Roentgenol Am J Roentgenol 2000; 174: 837-844
• 23 Townsley P, Ravenscroft A, Bedforth N. Ultrasound-guided spinal accessory nerve blockade in the diagnosis and management of trapezius muscle-related myofascial pain. Anaesthesia 2011; 66: 386-389
• 24 Sripada R, Bowens Jr C. Regional anesthesia procedures for shoulder and upper arm surgery upper extremity update – 2005 to present. International anesthesiology clinics 2012; 50: 26-46
• 25 Kierner AC, Zelenka I, Heller S et al. Surgical anatomy of the spinal accessory nerve and the trapezius branches of the cervical plexus. Arch Surg 2000; 135: 1428-1431
• 26 Pereira MT, Williams WW. The spinal accessory nerve distal to the posterior triangle. J Hand Surg Br 1999; 24: 368-369
• 27 Kessler J, Gray AT. Course of the spinal accessory nerve relative to the brachial plexus. Reg Anesth Pain Med 2007; 32: 174-176