Dual Thoracodorsal Nerve Origins With Coexisting Conventional and Accessory Thoracodorsal Arterial Channels: A Cadaveric Case With Additional Axillary Variants

The thoracodorsal artery and nerve are key structures in axillary, breast, and reconstructive surgery. During further dissection of the right axilla of a 78-year-old formalin-embalmed donated male cadaver, two thoracodorsal nerves were identified arising independently from the posterior cord at separate proximal levels. Two arterial channels also coursed toward the thoracodorsal territory: a conventional thoracodorsal artery arising through the subscapular system and an additional thoracodorsal-directed channel arising from a lateral thoracic-thoracodorsal trunk. Because accompanying venous anatomy, terminal intramuscular territories, and functional contributions were not mapped, these findings are described as two independently arising thoracodorsal nerve trunks with conventional and accessory thoracodorsal arterial channels rather than as two complete, functionally independent neurovascular pedicles. An accessory superior thoracic arterial channel and a communication between an intercostobrachial branch and a posterior-cord-derived branch situated between the two thoracodorsal nerve origins were also observed. The same donor and right axilla had previously been reported for other muscular and axillary branching variants; therefore, this report focuses on findings recognized during subsequent deeper dissection and explicitly separates them from previously published anatomy. These observations expand the spectrum of thoracodorsal and axillary variation and emphasize the need to identify unexpected arterial and neural structures during surgery without assuming that close spatial association necessarily represents a duplicated complete pedicle.