Anomalous azygos veins - its embryological basis and clinical significance

Authors

  • Uma Shivanal Department of Anatomy, Mysore Medical College and Research Institute, Mysore, Karnataka
  • Geethanjali HT Department of Anatomy, Mandya Institute of Medical Sciences, Mandya, Karnataka

DOI:

https://doi.org/10.18203/2320-6012.ijrms20150624

Keywords:

Azygos vein, Hemiazygos vein, Accessory azygos vein

Abstract

Background: The anatomical knowledge of the variability of the azygos venous system is important for the surgical interventions of the posterior mediastinum and also during radiological investigations/diagnosis especially CT and MRI. The variant azygos venous system might be confused with thoracic aorta aneurysms, lymphadenopathy and tumours of posterior mediastinum.

Methods: The present study was undertaken on 10 embalmed adult human cadavers irrespective of sex, used for undergraduate dissection from the Department of Anatomy, Mandya Institute of Medical Sciences, Mandya. In this present study, formation, course and termination pattern of azygos system of veins was observed in 10 dissected human cadavers. Out of which 2 cadavers showed different types of variations.

Results: In the present study, normal azygos venous system was found in 8 specimens accounting for 80%. Variations were found in 2 specimens (20%); one specimen presented with connection between accessory hemiazygos vein and hemiazygos vein, 3 transverse channels across vertebral column and the other specimen showed absence of accessory hemiazygos vein and shifting of azygos vein towards midline.

Conclusions: Accurate knowledge about these kinds of variations is very important to identify, especially in the computed tomography and magnetic resonance imaging of mediastinum. The abnormal azygos venous system may easily be confused with aneurysm, lymphadenopathy and other abnormalities like tumor. It is important to keep these kinds of variations in mind while performing the mediastinal operations or surgery of large vessels.  

 

References

Susan Standring. Azygos vein. In: Susan Standring, eds. Gray’s Anatomy: the Anatomical Basis of Clinical Practice. 40th ed. London: Churchill Livingstone Elsevier; 2008: 939-940.

Datta AK. Thorax and abdomen. In: Datta AK, eds. Essentials of Human Anatomy. 9th ed. Kolkata: Current Books International; 2010: 100-102.

Kutoglu T, Turut M, Kocabiyik N, Ozan H, Yildirim M. Anatomical analysis of azygos vein system in human cadavers. Rom J Morphol Embryol. 2012;53(4):1051-6.

Naveen K, Satheesha NB, Surekha S, Somayaji SN. Azygos ladder and looped thoracic duct - a case report. IJAV. 2011;4:80-2.

Elzbieta KS, Marcin W, Michal S, Helena K. Variability of the azygos vein system in human foetuses. Folia Morphol. 2003;62(4):427-30.

Bergman RA, Afifi AK, Miyauchi R. Azygos vein. Illustrated Encyclopedia of Human Anatomic Variation: Opus II: Cardiovascular system: Veins: Head, Neck and Thorax. Anatomy Atlases, 2015. Available at: http://www.anatomyatlases.org/AnatomicVariants/Cardiovascular/Text/Veins/Azygos.shtml.

Arslan G, Cebuk M, Ozkaynak C, Sindel T, Lüleci E. Absence of the azygos vein. J Clin Imaging. 2000;24:157-8.

Quraishi MB, Mufti O, Wase A. Absent left and right superior vena cava and azygos continuation of inferior vena cava: a rare anomaly of systemic venous return. J Invasive Cardiol. 2010;22:E159-61.

Quadros LS, Potu BK, Guru A, Pulakunta T, Ray B, D’Silva SS, et al. Anomalous azygos venous system in a south Indian cadaver: a case report. Cases J. 2009;2:6746.

Lapierre C, Siles A, Bigras JL. Partial anomalous pulmonary venous return to the azygos vein: an unusual case. Pediatr Cardiol. 2010;31:749-50.

Uemura M, Takemura A, Ehara D, Yasumitsu H, Ohnishi Y, Suwa F. Left superior vena cava with left azygos vein. Okajimas Folia Anat Jpn. 2009;86:55-60.

Nathan H. Anatomical observations on the course of the azygos vein (vena azygos major). Thorax. 1960;15:229-32.

Lydia SQ, Bhagath KP, Anitha G, Thejodhar P, Biswabina R, Suhani SD, et al. Anomalous azygos venous system in a south Indian cadaver: a case report. Cases J. 2009;2:6746.

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Published

2017-01-12

How to Cite

Shivanal, U., & HT, G. (2017). Anomalous azygos veins - its embryological basis and clinical significance. International Journal of Research in Medical Sciences, 3(9), 2323–2326. https://doi.org/10.18203/2320-6012.ijrms20150624

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Original Research Articles