High-resolution ultrasound accurately identifies the medial antebrachial cutaneous nerve at the midarm level: A clinical anatomic study

OBJECTIVES: The present prospective volunteer study was designed to describe a technique for ultrasound identification of the medial antebrachial cutaneous nerve (MACN) and a technique for ultrasound-guided blockade of this sensory nerve of the upper limb. METHODS: Twenty male volunteers were included in this study. After cross-sectional ultrasound identification of the MACN at the upper arm, where it is closely adjacent to the basilic vein, a selective blockade via an in-plane needle guidance technique was performed with 0.3 mL of mepivacaine 1.5% under direct ultrasound visualization. Sensory loss to pinprick at the upper extremity was evaluated and compared with the contralateral side. RESULTS: Constant ultrasound visualization of the MACN adjacent to the basilic vein at the upper arm level was possible in all cases. Blockade of the MACN under direct visualization was associated with a 100% success rate. CONCLUSIONS: The results of this investigation enable selective blockade of the MACN via ultrasound. Moreover, our data provide insight regarding the specific anatomic course and the integrity of this sensory nerve, which could be used for plastic and reconstructive surgical indications and for diagnosis of nerve injury. Copyright © 2011 by American Society of Regional Anesthesia and Pain Medicine.