Abstract
Combined ultrasound-guided blockade of the suprascapular and axillary nerves has been proposed as an alternative to interscalene blockade for pain control in shoulder joint pathology or post-surgical care. This technique could help avoid respiratory complications and/or almost total upper limb palsy. Nowadays, the axillary nerve blockade is mostly performed using an in-plane caudal-to-cephalic approach from the posterior surface of the shoulder, reaching the nerve immediately after it exits the neurovascular quadrangular space (part of the spatium axillare). Despite precluding most respiratory complications, this approach has not made post-surgical pain relief any better than an interscalene blockade, probably because articular branches of the axillary nerve are not blocked. Cephalic to caudal Methylene Blue injections were placed in the first segment of the axillary nerve of six Thiel-embalmed cadavers using an ultrasound-guided anterior approach in order to compare the distribution with that produced by a posterior approach to the contralateral axillary nerve in the same cadaver. Another 21 formalin-fixed cadavers were bilaterally dissected to identify the articular branches of the axillary nerve. We found a good spread of the dye on the axillary nerve and a constant relationship of this nerve with the subscapularis muscle. The dye reached the musculocutaneous nerve, which also contributes to shoulder joint innervation. We describe the anatomical landmarks for an ultrasonography-guided anterior axillary nerve blockade and hypothesize that this anterior approach will provide better pain control than the posterior approach owing to complete blocking of the joint nerve. This article is protected by copyright. All rights reserved.
González-Arnay, Emilio