Intercostobrachial Nerve Block

Indications and Clinical Considerations

Intercostobrachial cutaneous nerve block is used primarily as an adjunct to brachial plexus block rather than as a stand-alone regional anesthesia and pain management procedure. The intercostobrachial cutaneous nerve is not part of the brachial plexus and is often not adequately blocked when performing standard brachial plexus block techniques. This means that the medial and posterior aspect of the arm just below the axilla remains unanesthetized, making prolonged use of a pneumatic tourniquet or the performance of surgical procedures in this region problematic ( Fig. 52.1 ). The intercostobrachial cutaneous nerve is often damaged or transected during radical mastectomy surgery and has been implicated in the evolution of postmastectomy pain syndrome. The nerve may also subserve referred pain from the cardiac region.

FIG. 52.1, Intercostobrachial nerve block is not commonly used as a stand-alone pain management technique; rather, it is used to augment brachial plexus block and to provide anesthesia of the medial cutaneous surface of the arm and axilla to decrease tourniquet pain during intravenous regional anesthesia.

Clinically Relevant Anatomy

The intercostobrachial cutaneous nerve is derived from fibers of the lateral cutaneous branch of the second intercostal nerve ( Fig. 52.2 ). After piercing the intercostalis and serratus anterior muscles, the intercostobrachial cutaneous nerve traverses the axilla, where it provides communicating branches to the median cutaneous nerve. The intercostobrachial cutaneous nerve exits the axilla along with the median cutaneous nerve to provide cutaneous sensory innervation to medial and posterior aspect of the upper extremity ( Figs. 52.3 and Fig. 52.4 ). The superficial location of this nerve makes it easily accessible for ultrasound-guided nerve block.