Abstract
Introduction The azygos system of veins (ASV) is a very variable structure characterized as a
communication between the inferior and superior vena cava, having the azygos vein
(AV), the hemiazygos vein (HV), and the accessory hemiazygos vein (HAV) as its main
components, which are responsible for the mediastinal viscera and for the thoracoabdominal
wall drainage. The aim of the present study is to report an anatomical variation found
in a male cadaver at the Laboratory of Anatomy of the University Center of UNIFACISA,
Campina Grande, PB, Brazil.
Case Report In the posterior mediastinum, the union of the HV, of the HAV, and of the 8th left posterior intercostal vein formed a common trunk at the level of the left 8th intercostal space, crossing the mediastinum posterior to the aorta artery, ending
up in the AV, in the right hemithorax.
Conclusion The study of the anatomical variations of the ASV is important and will provide knowledge
for physicians not to confuse them with pathological processes in imaging exams. Moreover,
it can provide safety in surgical approaches of the thorax.
Keywords
azygos system - anatomic variation - thorax drainage - vascular variation and macroscopic
human anatomy.
