[Anatomical basis for infraclavicular brachial plexus block].

BACKGROUND AND OBJECTIVES This study shows the constant infraclavicular fossa presence, aiming at using it as a pathway for infraclavicular brachial plexus block. Determining the point where brachial plexus fascicles may be located within the fossa, the authors have proposed measurements from the anterior surface of the clavicle and the angle formed by the deltoid muscle and the clavicle (deltoclavicular angle). The first measurement allows the in-depth location of the site crossed by the brachial plexus. The second determines fascicles projection within the fossa, corresponding to the needle insertion point on the skin. METHODS Measurements were made between the anterior surface of the clavicle and brachial plexus fascicles, and from the deltoclavicular angle to superficial fascicles projection. Based on the anatomic findings a technique of infraclavicular brachial plexus approach was proposed. RESULTS A hundred infraclavicular regions in cadavers were analyzed. Infraclavicular fossa was detected in 96 cases where brachial plexus fascicles were totally or partially (97.9%) located. The distance between the anterior surface of the clavicle and brachial plexus fascicles was in average of 2.49 cm and from the deltoclavicular angle to superficial fascicles projection was 2.21 cm. CONCLUSIONS Values obtained allow for the precise location of the needle insertion point which, when perpendicular to the skin, reaches brachial plexus without danger of causing pneumothorax or vascular injury, providing more safety to anesthesiologists and allowing the return to the practice of brachial plexus block below the clavicle.