Fig. 2
From: The inferior vena cava: anatomical variants and acquired pathologies
The mature IVC is composed of infrarenal (right supracardinal vein), renal (right suprasubcardinal and intersubcardinal anastomoses), suprarenal (right subcardinal vein) and hepatic (vitelline veins) segments. Renal and suprarenal segments are separated by the dashed line. Posterior cardinal veins persist as paired common iliac veins which join to form the iliac confluence, whilst supracardinal veins contribute to the azygos venous system draining into the superior vena cava. The gonadal and suprarenal veins are derived from subcardinal veins