Comparison of Selective Trunk Block and Corner Pocket Approach of Supraclavicular Brachial Plexus Block : A Prospective Randomized Controlled Trial

Supraclavicular brachial plexus block (BPB) is the most used regional anesthesia technique in upper limb surgeries. It is considered equivalent to spinal anesthesia in these surgeries due to its rapid onset, reliable, effective and comprehensive block of all the necessary nerves of upper limb. Ultrasound guided corner pocket approach is the recommended and most widely practiced technique for supraclavicular BPB. In this approach, a single injection of local anesthetic is given  at the angle formed between the first rib and inferolateral side of subclavian artery 1. The limitation of this approach, however, is the deeper location of T1 ventral ramus and inferior trunk compared to superior and middle trunks. This often results in inferior trunk (C8-T1, ulnar nerve) sparing. Previous studies, also concurred this and observed an ulnar nerve sparing of 5-30%  with this approach, which can result in incomplete anesthesia for  these surgeries.2-5

With the recent updates in ultrasound resolution, it is now feasible to isolate and locate all three trunks of brachial plexus. Dr Karmakar et al. recently described one such method called as Sequential Ultrasound Imaging Technique (SUIT) to identify all the three trunks.4,5  This enables us to block each trunk separately, making Selective Trunk Block (SeTB) a potential approach to provide comprehensive and complete anesthesia or analgesia for all the patients undergoing any upper limb surgery. In this technique, we sequentially identify ventral rami of all the roots and formation of all trunks of brachial plexus.6,7 After obtaining an appropriate ultrasound view, local anesthetic is deposited two sites – one between superior and middle trunk, another at the inferior trunk.

We therefore hypothesize that an approach to selectively identify and block all three trunks should be able to produce a comprehensive and complete anasethesia for all upper limb surgeries without ulnar nerve sparing common with corner pocket approach.

REFERENCES

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2. Trivedi, Saurabh; Gupta, Srishti1; Bhardwaj, Hemendra; Sahoo, Tapan Kumar; Gupta, Seema; Trivedi, Gaurav2. Efficacy of intertruncal and corner-pocket approaches of ultrasound-guided supraclavicular block in terms of ulnar nerve blockade: A randomised controlled study. Indian Journal of Anaesthesia 67(9):p 778-784, September 2023. | DOI: 10.4103/ija.ija_45_23
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