Features of the spatial orientation of the thoracodorsal nerve bundles

Abstract

BACKGROUND: Studying the spatial arrangement of nerve bundles makes it possible to better understand the characteristics of the occurrence and mechanisms of injuries to peripheral nerves, to develop and perform new reconstructive operations.
 AIM: To identify the features of the route, spatial orientation and relationships of the thoracodorsal nerve bundles along its entire length.
 MATERIAL AND METHODS: Intrastem dissection of 121 thoracodorsal nerves was performed in the corpses of men and women aged 40–97 years. The obtained indicators of the length (mm) and angles of deviation (degrees) of the thoracodorsal nerve bundles at different levels of their entire path were checked for normality of distribution using the Shapiro–Wilk test. When describing the studied indicators, the median (Me) and quartile intervals (Q1, Q3) were determined, and the significance of intergroup differences was determined using the Mann–Whitney U test.
 RESULTS: Along the entire path, the bundles of the thoracodorsal nerve change their spatial position 6 times and their relationship with each other 1 time. The closer the bundles are to the spinal cord and spine, the more changes (85.7%); the further to the periphery, the fewer (14.3%). The bundles of the thoracodorsal nerve are located twice in the horizontal plane, and in the proximal half of the C7 spinal nerve they are twisted relative to each other by 180° [170°; 190°], change places: the sensory ones move from the posterior position to the anterior one, and the motor one — from the anterior to the posterior one. The bundles of the thoracodorsal nerve deviate downward 4 times in the frontal plane at a total angle of 105° [95°; 115°], and in the sagittal plane they change their position 2 times and move from an oblique-anterior (15° [5°; 25°]) to an oblique-posterior (20° [10°; 30°]) position.
 CONCLUSION: The route of passage of the thoracodorsal nerve bundles along the entire path from the spinal cord to the latissimus dorsi muscle consists of eight levels of different lengths, 6 times they change their spatial orientation and 1 time their relationship with each other.