Ultrasonographic Study of the Anatomical Relationship Between the Lateral Antebrachial Cutaneous Nerve and the Cephalic Vein

Abstract

Objective: To define the anatomy of the lateral antebrachial cutaneous nerve (LABCN) and the cephalic vein (CV) in the anterior forearm region of living humans using ultrasonography for preventing LABCN injury during cephalic venipuncture.

Methods: Thirty forearms of 15 healthy volunteers were evaluated using ultrasonography to identify the point where the LABCN begins to contact with the CV, and the point where the LABCN separates from the CV. The LABCN pathway in the forearm in relation to a nerve conduction study was also evaluated.

Results: The LABCNs came in contact with the CV at a mean of 0.6±1.6 cm distal to the elbow crease, and separated from the CV at a mean of 7.0±3.4 cm distal to the elbow crease. The mean distance between the conventionally used recording points (point R) for the LABCN conduction study and the actual sonographic measured LABCN was 2.4±2.4 mm. LABCN usually presented laterally at the point R (83.3%).

Conclusion: The LABCN had close proximity to the CV in the proximal first quarter of the forearm. Cephalic venipuncture in this area should be avoided, and performed with caution if needed.

Keywords: Lateral antebrachial cutaneous nerve; Phlebotomy; Ultrasonography.

Fig. 1. Schematic relationship of the lateral antebrachial cutaneous nerve (LABCN), cephalic vein (CV), and biceps tendon (BT) at the anterior aspect of the forearm. Point M, meeting point of LABCN and CV; Point A, point where LABCN and CV come apart.

Fig. 2. Transverse view of ultrasonographic images of the course of the LABCN (arrows) at the elbow crease level (A), at the level of point M and A (B, C), and at the distal 12 cm level (D). LABCN, lateral antebrachial cutaneous nerve; CV, cephalic vein; Point M, meeting point of LABCN and CV; Point A, point where LABCN and CV come apart.