Layered relationship of Langer's axillary arch with the axillary neurovascular bundle: a cadaveric case report

Langer's axillary arch (LAA) is a common muscular variant in the axilla, yet detailed descriptions of its layered and level-dependent relationships with the axillary neurovascular bundle remain limited.

During routine educational dissection of a 79-year-old Korean male cadaver, a right-sided LAA was identified. The arch examined sequentially by anatomical layer. Morphometric data were obtained using a digital caliper. The LAA arose from the latissimus dorsi as a muscular slip (22.5 mm wide), tapered cranially, and inserted as a tendinous slip into the coracoid process (2.5 mm wide), with a total length of 45.7 mm. Along its course, the muscular portion crossed the basilic vein, which appeared slightly flattened at the point of contact, then spanned the venous interval between the basilic and brachial veins, with axillary arterial branches lying deep to the superficial venous layer. More superiorly, the tendinous portion crossed the brachial vein near its junction with the axillary vein; notably, the brachial vein was interposed between the tendinous LAA and the region where the lateral and medial cords of the brachial plexus converged, after which the LAA passed over the surface of the lateral cord before insertion.

This report provides a layer-by-layer depiction of a musculotendinous LAA that overlies multiple components of the axillary neurovascular bundle, including an observed flattening of the basilic vein and a distinctive configuration in which the brachial vein lies between the tendinous arch and the brachial plexus cords. Recognition of such level-dependent relationships may aid anatomical interpretation and surgical orientation during axillary procedures.