Anatomical Relationship Between the Terminal Thoracic Duct and Brachial Plexus: A Cadaveric Study

Objective To study the anatomical relationship between the terminal portion of the thoracic duct (TD) and the brachial plexus (BP). Methods Anatomical study performed on 72 fresh cadavers, dissected only on the left side. Anatomical structures were preserved, and measurements were performed using an digital caliper. Statistical analysis was performed with a 95% confidence interval and a precision level set at 3 mm. Results The TD terminated on the left side in 100% of specimens. Three termination sites of the thoracic duct (TD) were identified: the internal jugular vein (50.0%), the junction between the internal jugular and subclavian veins (45.8%), and directly into the subclavian vein (4.2%). The TD ran parallel to the brachial plexus (BP) in 62.5% of cases and perpendicular in 37.5%. The structures closest to the TD were the phrenic nerve and the C5 root, at an average distance of 17 mm. Discussion This anatomical proximity has important surgical implications. Understanding these relationships may reduce the risk of TD injury during BP surgeries. Conclusion There is a consistent anatomical relationship between the TD and BP, typically within 2 cm, highlighting the need for careful dissection in this region.