Inferior vena cava (IVC) is the largest vein of the body and is formed by the union of the two common iliac veins at the level of the fifth lumber vertebra, and returns blood to the right atrium from the lower half of the body below the diaphragm. The complex development of the IVC, from the three primitive paired veins is responsible for numerous variations observed in the common basic plan of this vein. These anomalies may not be detected during life but have a great clinical significance in radiological and surgical practice. During routine cadaveric dissection in a 50 year old female cadaver, variations were observed in the veins forming the inferior vena cava. The variations observed were as follows: The right common iliac vein was absent, thus the inferior vena cava was formed by the union of left common iliac vein and, right external iliac vein and the right internal iliac vein. The right external iliac vein further showed duplication into anterior division and a posterior division before its termination into the inferior vena cava. It was interesting to note that the right external iliac artery coursed through the gap between the two divisions of the external iliac vein. The embryological basis and clinical significance of unusual variations of major veins forming the inferior vena cava are discussed.
IVC;left Common illiac vein;Right external iliac vein;Right internal iliiac vein;embryogenesis of pelvic veins;