Anatomical variations of the azygos venous system

Abstract

ABSTRACT Introduction: The azygos venous system consists of the azygos vein on the right side and the hemiazygos and accessory hemiazygos on the left side. The latter two are said to be the tributaries rather than the equivalent of the azygos vein. This unpaired venous system is said to be full of anatomical variations and hence of much clinical significance. Aims: to study and report the prevalence of normal and anomalous variations of the azygos venous system in the region of East –Godavari district, Andhra-Pradesh (India) Methods: the present study was carried out in the Department of Anatomy, KIMS & RF, Amalapuram spanning over a period of 2 years. A total of 40 cadavers irrespective of age and sex were chosen. The entire course of the azygos venous system in these 40 cadavers was carefully noted and documented. Results: 29 cadavers showed the normal venous patterned as described in literature. The other 11 cases irrespective of age and sex showed anatomical variations which would be subsequently described in the article. Conclusion: knowledge of such variations exhibiting different drainage pattern is significant during mediastinal surgeries as it may become a potential source of hemorrhage. Also presence of such variations may lead to misinterpretation of thoracic CT and MRI findings of the posterior mediastinum.