The features of the intrafascicular structure of the thoracodorsal nerve trunk in terms of ­restoring afferent innervation in breast reconstruction

Abstract

Aim. To study of anatomical and topographic features and the intrafascicular structure of the thoracodorsal nerve trunk in the brachial plexus. Methods. The study was performed on the brachial plexus preparations of 80 male and female corpses. Short and long branches, secondary bundles, primary trunks, spinal nerves, anterior and posterior roots of the spinal cord were layer-by-layer anatomically prepared from brachial plexus. The angles of inclination from the arising site of the thoracodorsal nerve, the topography throughout and after entering the latissimus dorsi muscle were studied. The length and thickness of the thoracodorsal nerve, including the extramuscular and intramuscular parts, were measured. ­After isolation and fixation of the preparations, intrafascicular dissection of the thoracodorsal nerve was performed throughout the brachial plexus, by using microsurgical instruments and a binocular magnifier. Results. The length of the thoracodorsal nerve consists of extramuscular and intramuscular parts and was equal to 17.9 cm, of which the extra-muscular part was three-quarters of the total length of the nerve. The nerve trunk dissection revealed that the thoracodorsal nerve consists of 1–4 nerve fascicles and most frequently, in 46.2% of preparations, the thoracodorsal nerve arises from the C 7 nerve root. The presence of motor and sensory portions of nerve fibers in the thoracodorsal nerve was found. In 90.2% of the preparations, the motor portion was located in the posterior-lateral part of the nerve and sensory in the anterior-medial. In most cases, both the sensory and motor fas­cicles arose from C 7 , or motor fascicle from C 7 and sensory from C 8 . Conclusion. The intrafascicular dissection of the thoracodorsal nerve revealed microtopography of the sensitive and motor portions of nerve fibers in the nerve and along the entire length of the brachial plexus; in breast reconstruction, after mastectomy with thoracodorsal flap for the preservation of afferent innervation, it is recommended to cross only motor fibers of the thoracodorsal nerve.