Intertruncal approach to the supraclavicular brachial plexus, current controversies and technical update: a daring discourse.

We propose a new approach to local anesthetic injection for the supraclavicular brachial plexus block: an intertruncal approach by which local anesthetic is deposited in the two adipose tissue planes between the upper and middle and the middle and lower trunks. We present sonographic and microscopic images to illustrate the relevant anatomy. This approach offers potential advantages over the 'corner pocket' technique in that it results in consistent local anesthetic spread to the three plexus trunks and the needle endpoint lies farther away from the pleural surface which is important for the prevention of pneumothorax. It also offers an advantage over the 'intracluster' approach as it purposefully avoids intraneural injection respecting the integrity of the epineurium of individual trunks. Comparative studies are required to confirm that these anatomic and technical advantages result in improved outcomes.