An Anatomical Study of the Length of the Neural Pedicle after the Bifurcation of the Thoracodorsal Nerve: Implications for Innervated Free Partial Latissimus Dorsi Flaps

Background: For innervated functional muscle transplant procedures, it is essential to have knowledge about the length of nerve pedicles available for nerve anastomosis. For the latissimus dorsi muscle, the thoracodorsal nerve divides into two funicles that separately innervate the medial and lateral portions of the muscle. This suggests the possibility of a multiple, segmentally innervated latissimus dorsi muscle transfer. The branching and length of the thoracodorsal nerve distal to the bifurcation have not been described. This surgical-anatomical study presents anatomical data on these practical/clinical issues. Methods: Eleven latissimus dorsi muscles were dissected in eight adult embalmed human specimens. The thoracodorsal neurovascular bundle was dissected from insertion to proximal of the bifurcation. Measurements were taken indirectly from standardized photographic images and analyzed with ImageJ and standard spreadsheet software. Results: The mean age of the specimens was 66 years. The median pedicle length of the lateral part of the muscle was 3.8 cm (range, 2.41 to 5.93 cm). The median length of the medial branch was 3.49 cm (range, 1.7 to 5.12 cm). Proximal branching of the medial pedicle of the bifurcation was identified in approximately two-thirds of the specimens and had a median of 3.55 cm (range, 2.54 to 4.68 cm). The veins and arteries showed a similar pattern, with a median length slightly less than that of the thoracodorsal nerve. Conclusion: The separate neurovascular branches and its minimal pedicle length make the latissimus dorsi muscle very suitable for single functional free muscle transfer, using only the lateral part of the latissimus dorsi muscle, and double functional free muscle transfer using only one vascular pedicle. (Plast. Reconstr. Surg. 127: 210, 2011.)