The "axillary tunnel": an anatomic reappraisal of the limits and dynamics of spread during brachial plexus blockade.

Background: Various anatomic factors have been described as affecting the distribution of a solution injected around the brachial plexus. Using computerized axial tomography dye studies, we introduce a new concept.

Methods: Ten patients with brachial plexus catheters sited using the bent needle supraclavicular technique were studied.