Anatomy variation of brachial plexus trunks during supraclavicular nerve block: clinical image

For successful ultrasound-guided peripheral nerve block, recognition of anatomy of interest either as normal or abnormal is vital. We report the image of anatomical variation of brachial plexus at supraclavicular level in a 28-year-old healthy male with no significant medical history and no prior neck surgery, injury, or radiation exposure who came for wrist surgery. A caudal tilt towards ipsilateral lung during supraclavicular ultrasound scanning revealed the presence of superior and middle trucks, superior and medial to subclavian artery respectively rather than being situated lateral to artery along with inferior trunk (Fig. 1). Anomalies of brachial plexus have usually been reported in interscalene region.¹ Rarely a single trunk abnormality has been reported in supraclavicular region.² Thus, our report of images of deviation of two trunks are clinically compelling. When there are alterations in signaling between mesenchymal and neuronal growth cones or circulatory factors at time of development of brachial plexus such abnormalities can occur.³ The anomaly recognition allowed us to individually block the trunks and achieve a successful surgical anesthesia (Figs. 2 and 3). In conclusion, anatomical variation of brachial plexus can happen, and use of ultrasound helps identifying them to safely and successfully administer the block.

Figure 1
Brachial plexus anomaly at supraclavicular level with superior and middle trunks superior and medial to subclavian artery, respectively.

Figure 2
Targeted blocking of superior and middle trunks.

Figure 3
Targeted blocking of inferior trunk.

References

• ¹
  Kessler J, Gray AT. Sonography of scalene muscle anomalies for brachial plexus block. Reg Anesth Pain Med. 2007;32: 172-3.
• ²
  Chin KJ, Niazi A, Chan V. Anomalous brachial plexus anatomy in the supraclavicular region detected by ultrasound. Anesth Analg. 2008;107:729-31.
• ³
  Padur AA, Kumar N, Shanthakumar SR, Shetty SD, Prabhu GS, Patil J. Unusual and unique variant branches of lateral cord of brachial plexus and its clinical implications ‒ A cadaveric study. J Clin Diagn Res. 2016;10:AC01-4.

Publication Dates

• Publication in this collection
  14 Oct 2022
• Date of issue
  Nov-Dec 2022

History

• Received
  31 May 2022
• Accepted
  24 June 2022