BLOCK AT A GLANCE
Block of the brachial plexus at the medial aspect of the infraclavicular fossa, close to the midpoint of the clavicle.
Indications: Same as with traditional infraclavicular block—anesthesia and analgesia for the upper extremity, elbow, forearm, and hand surgeries. Analgesia for shoulder procedures.
Goal: Local anesthetic (LA) spread between the three cords of the brachial plexus
Local anesthetic volume: 15 to 20 mL
The ultrasound (US)-guided brachial plexus block at the costoclavicular space has been recently described as an alternative approach to the traditional infraclavicular block (sagittal paracoracoid approach deep to the pectoral muscles). Of note, the site of injection is similar to the landmark-based “vertical infraclavicular brachial plexus block” (VIB) described by Kilka et al. The compact organization of the brachial plexus at this level, clustered lateral to the artery and more superficial than in the traditional approach, may be more favorable to block with a single needle pass. The more cephalad spread of LA toward the supraclavicular fossa also may reach the trunks of the brachial plexus and, therefore, provide shoulder analgesia.
Few recent studies suggest that the onset of sensory and motor block may be somewhat faster compared to the paracoracoid approach and that lower volumes of LA may be efficacious.
Limitations and Specific Risks
The cephalic vein and the thoracoacromial artery may be on the needle’s path. Care must be taken to avoid these vessels during needle advancement. Otherwise, risks are similar as for infraclavicular block and mostly related to the proximity of the axillary artery, vein, and the pleura.
The transition from trunks to cords of the brachial plexus occurs at the costoclavicular space, where all the neural elements travel flattened, arranged laterally to the axillary artery. It is at this level that the lateral and medial pectoral nerves leave the corresponding cords, whereas the subscapular and thoracodorsal nerves leave the posterior cord. More distally, the cords separate from each other and surround the axillary artery as they travel deep to the pectoral muscles (Figure 16-1).
Functional anatomy of the brachial plexus for the costoclavicular approach. Note the relationship of the brachial plexus cords to the proximal axillary artery. BP, brachial plexus; AV, axillary vein; AA, axillary artery.
CROSS-SECTIONAL ANATOMY AND ULTRASOUND VIEW
The cords of brachial plexus at this location lie between the subclavius and the anterior serratus muscle, lateral to the artery, in a consistent relationship to each other. The lateral cord is in the most superficial, the posterior and medial cords lie lateral and medial respectively sharing a common sheath. The second rib can be imaged deep to the serratus muscle. The axillary vein is located medially to the artery and ...