Skip to main content

Refining the ultrasound-guided interscalene brachial plexus block: the superior trunk approach

Raffinement du bloc interscalénique échoguidé du plexus brachial: la voie de la branche supérieure



The conventional ultrasound-guided interscalene block targets the C5 and C6 nerve roots at approximately the level of the cricoid cartilage where they lie in the groove between the anterior and middle scalene muscles. This technique, although effective at providing regional anesthesia of the shoulder, is associated with risks of phrenic nerve palsy, injury to the dorsal scapular and long thoracic nerves, and long-term postoperative neurologic symptoms. In this case report, we describe the ultrasound-guided superior trunk block. This procedure targets the C5 and C6 components of the brachial plexus more distally after they unite into the superior trunk but before the suprascapular nerve branches off.

Clinical features

We performed an ultrasound-guided superior trunk block to provide perioperative analgesia for ambulatory arthroscopic shoulder repair in a patient with moderate chronic obstructive pulmonary disease. The technique, relevant sonoanatomy of the brachial plexus, and the potential advantages of the superior trunk block are discussed.


The enhanced anatomical knowledge provided by ultrasound-guidance has allowed anesthesiologists to devise new block techniques and refine existing ones. The superior trunk block is an example of this refinement and is intended as an alternative to the conventional interscalene block for anesthesia of the shoulder. Further research is planned to confirm the efficacy and safety of the technique.



Le bloc interscalénique échoguidé conventionnel cible les racines nerveuses C5 et C6 approximativement à la hauteur du cartilage cricoïde où elles traversent un espace entre les muscles scalènes antérieur et moyen. Bien que cette technique produise une anesthésie régionale efficace de l’épaule, elle est associée à des risques de paralysie du nerf phrénique, de lésion du nerf dorsal de la scapula et des nerfs thoraciques longs, ainsi qu’à des symptômes neurologiques postopératoires à long terme. Dans ce rapport de cas, nous décrivons un bloc échoguidé de la branche supérieure. Cette procédure cible les branches C5 et C6 du plexus brachial plus distalement, après leur union pour former la branche supérieure, mais avant la division du nerf suprascapulaire.

Caractéristiques cliniques

Nous avons pratiqué un bloc échoguidé de la branche supérieure pour obtenir une analgésie périopératoire au cours d’une réparation de l’épaule par voie arthroscopique en ambulatoire chez un patient ayant une maladie pulmonaire obstructive chronique d’intensité modérée. La technique, l’anatomie échographique pertinente du plexus brachial et les avantages du bloc de la branche supérieure sont discutés.


L’amélioration des connaissances anatomiques procurée par l’échoguidage a permis aux anesthésiologistes de mettre au point de nouvelles techniques de blocs et de raffiner celles qui existent. Le bloc de la branche supérieure est un exemple de ce raffinement et est vu comme une technique de remplacement du bloc interscalénique conventionnel pour l’anesthésie de l’épaule. D’autres études sont prévues pour confirmer l’efficacité et l’innocuité de la technique.

This is a preview of subscription content, access via your institution.

Fig. 1
Fig. 2
Fig. 3
Fig. 4


  1. 1.

    Nadeau MJ, Levesque S, Dion N. Ultrasound-guided regional anesthesia for upper limb surgery. Can J Anesth 2013; 60: 304-20.

    PubMed  Article  Google Scholar 

  2. 2.

    Sites BD, Taenzer AH, Herrick MD, et al. Incidence of local anesthetic systemic toxicity and postoperative neurologic symptoms associated with 12,668 ultrasound-guided nerve blocks: an analysis from a prospective clinical registry. Reg Anesth Pain Med 2012; 37: 478-82.

    CAS  PubMed  Article  Google Scholar 

  3. 3.

    Lee JH, Cho SH, Kim SH, et al. Ropivacaine for ultrasound-guided interscalene block: 5 mL provides similar analgesia but less phrenic nerve paralysis than 10 mL. Can J Anesth 2011; 58: 1001-6.

    PubMed  Article  Google Scholar 

  4. 4.

    Riazi S, Carmichael N, Awad I, Holtby RM, McCartney CJ. Effect of local anaesthetic volume (20 vs 5 ml) on the efficacy and respiratory consequences of ultrasound-guided interscalene brachial plexus block. Br J Anaesth 2008; 101: 549-56.

    CAS  PubMed  Article  Google Scholar 

  5. 5.

    Merchant R, Chartrand D, Dain S, et al. Guidelines to the practice of anesthesia – revised edition 2014. Can J Anesth 2014; 61: 46-71.

    PubMed  Article  Google Scholar 

  6. 6.

    Maybin J, Townsley P, Bedforth N, Allan A. Ultrasound guided supraclavicular nerve blockade: first technical description and the relevance for shoulder surgery under regional anaesthesia. Anaesthesia 2011; 66: 1053-5.

    CAS  PubMed  Article  Google Scholar 

  7. 7.

    Sakamoto Y. Spatial relationships between the morphologies and innervations of the scalene and anterior vertebral muscles. Ann Anat 2012; 194: 381-8.

    PubMed  Article  Google Scholar 

  8. 8.

    Gutton C, Choquet O, Antonini F, Grossi P. Ultrasound-guided interscalene block: influence of anatomic variations in clinical practice (French). Ann Fr Anesth Reanim 2010; 29: 770-5.

    CAS  PubMed  Article  Google Scholar 

  9. 9.

    Filip P. Complex arithmetic at the brachial plexus roots. Reg Anesth Pain Med 2009; 34: 79-80.

    PubMed  Article  Google Scholar 

  10. 10.

    Mian A, Chaudhry I, Huang R, Risk E, Tubbs RS, Loukas M. Brachial plexus anesthesia: A review of the relevant anatomy, complications, and anatomical variations. Clin Anat 2014; 27: 210-21.

    PubMed  Article  Google Scholar 

  11. 11.

    Siegenthaler A, Moriggl B, Mlekusch S, et al. Ultrasound-guided suprascapular nerve block, description of a novel supraclavicular approach. Reg Anesth Pain Med 2012; 37: 325-8.

    PubMed  Article  Google Scholar 

  12. 12.

    Ip VH, Tsui BC. Lower interscalene approach for elbow surgery. Can J Anesth 20013; 60: 600-1.

  13. 13.

    Orebaugh SL, McFadden K, Skorupan H, Bigeleisen PE. Subepineurial injection in ultrasound-guided interscalene needle tip placement. Reg Anesth Pain Med 2010; 35: 450-4.

    PubMed  Article  Google Scholar 

  14. 14.

    Saporito A. Dorsal scapular nerve injury: a complication of ultrasound-guided interscalene block. Br J Anaesth 2013; 111: 840-1.

    CAS  PubMed  Article  Google Scholar 

  15. 15.

    Thomas SE, Winchester JB, Hickman G, DeBusk E. A confirmed case of injury to the long thoracic nerve following a posterior approach to an interscalene nerve block. Reg Anesth Pain Med 2013; 38: 370.

    PubMed  Article  Google Scholar 

  16. 16.

    Hanson NA, Auyong DB. Systematic ultrasound identification of the dorsal scapular and long thoracic nerves during interscalene block. Reg Anesth Pain Med 2013; 38: 54-7.

    PubMed  Article  Google Scholar 

  17. 17.

    Pakala SR, Beckman JD, Lyman S, Zayas VM. Cervical spine disease is a risk factor for persistent phrenic nerve paresis following interscalene nerve block. Reg Anesth Pain Med 2013; 38: 239-42.

    PubMed  Article  Google Scholar 

  18. 18.

    Hogan QH. Phrenic nerve function after interscalene block revisited: now, the long view. Anesthesiology 2013; 119: 250-2.

    PubMed  Article  Google Scholar 

  19. 19.

    Kaufman MR, Elkwood AI, Rose MI, et al. Surgical treatment of permanent diaphragm paralysis after interscalene nerve block for shoulder surgery. Anesthesiology 2013; 119: 484-7.

    PubMed  Article  Google Scholar 

  20. 20.

    Kessler J, Schafhalter-Zoppoth I, Gray AT. An ultrasound study of the phrenic nerve in the posterior cervical triangle: implications for the interscalene brachial plexus block. Reg Anesth Pain Med 2008; 33: 545-50.

    PubMed  Google Scholar 

  21. 21.

    Murata H, Sakai A, Hadzic A, Sumikawa K. The presence of transverse cervical and dorsal scapular arteries at three ultrasound probe positions commonly used in supraclavicular brachial plexus blockade. Anesth Analg 2012; 115: 470-3.

    PubMed  Article  Google Scholar 

Download references


Dr. Ki Jinn Chin is supported by a 2013-2015 Merit Award from the Department of Anesthesia, University of Toronto.


This work did not receive any direct funding support.

Conflicts of interest

None declared.

Author information



Corresponding author

Correspondence to Ki Jinn Chin MBBS.

Additional information

Author contributions

David Burckett-St.Laurent and Ki Jinn Chin contributed substantially to the conception and drafting of the article. David Burckett-St.Laurent, Vincent Chan, and Ki Jinn Chin contributed substantially to the design and drafting of the article.

Electronic supplementary material

Below is the link to the electronic supplementary material.

Supplementary material 1 (WMV 8107 kb)

Rights and permissions

Reprints and Permissions

About this article

Verify currency and authenticity via CrossMark

Cite this article

Burckett-St.Laurent, D., Chan, V. & Chin, K.J. Refining the ultrasound-guided interscalene brachial plexus block: the superior trunk approach. Can J Anesth/J Can Anesth 61, 1098–1102 (2014).

Download citation


  • Brachial Plexus
  • Formoterol
  • Tiotropium
  • Tiotropium Bromide
  • Suprascapular Nerve