[A partially duplicated vena cava inferior: clinical, macroscopic and embryologic anatomy].

Anomalies of the inferior vena cava (IVC) can become unexpected obstacles during anterior surgery exposures of the lumbar spine. Starting from a recently observed case of a partially bilateral IVC, the literature, both clinical and anatomical, was reviewed with particular respect to the requirements of spine surgery. Based on extensive radiological (especially phlebographic), surgical, and anatomical investigations, the frequency of left sided or bilateral IVC can be figured out at about 2%. The embryogenesis of the variation is contested. Our observations comprising 45 human embryos confirm the conception according to which the infrarenal segment of IVC originates from the sacrocardinal (and not from the supracardinal) vein.