A left<unk>  vena cava results from regression of the right supracardinal vein with<unk> e of the left supracardinal vein.
The prevalence is 0.2%–0.5%
The major clinical significance of this anomaly is the potential for misdiagnoses as left sided paraaortic lymphadenopathy.
Spontaneous rupture of an abdominal aortic aneurysm into a left<unk>  vena cava has been reported.
Transjugular access to the infrarenal<unk>  vena cava for placement of an<unk>  vena cava filter may be difficult.
Typically, the left<unk>  vena cava joins the left renal vein, which crosses anterior to the aorta in the normal fashion, uniting with the right renal vein to form a normal right sided prerenal<unk>  vena cava.  
Image 1 - Duplication of<unk>  vena cava. This is a not uncommon variation. The left sided IVC (black arrow) most commonly ends in the normal left renal vein. Image 2 - Duplication of superior vena cava. This is a rare variation of the SVC. The left sided SVC (white arrow) is draining into the left atrium, thereby bypassing the pulmonary circulation. The right SVC is normal.   (Image courtesy of Dr Abhijit Datir)
Image 1 - Duplication of<unk>  vena cava. This is a not uncommon variation. The left sided IVC (black arrow) most commonly ends in the normal left renal vein. Image 2 - Duplication of superior vena cava. This is a rare variation of the SVC. The left sided SVC (white arrow) is draining into the left atrium, thereby bypassing the pulmonary circulation. The right SVC is normal.   (Image courtesy of Dr Abhijit Datir)
Persistent left inferior vena cava
Persistent left superior vena cava
Double inferior vena cava
Congenital stenosis of vena cava
Aberrant subclavian artery
Interrupted aortic arch
Pruned pulmonary vasculature
Persistent thyroglossal duct