The internal vertebral venous plexuses (intraspinal veins) lie within the vertebral canal in the epidural space,[1][2] embedded within epidural fat.[2][3] They receive tributaries from bones, red bone marrow, and spinal cord. They are arranged into four interconnected, vertically oriented vessels - two situated anteriorly, and two posteriorly:[3]
The anterior internal vertebral venous plexus[2] consists of two large plexiform veins situated upon the posterior surfaces of the vertebral bodies and intervertebral discs on either side of the posterior longitudinal ligament (underneath this ligament they are interconnected by transverse branches into which the basivertebral veins open).[3]
The anterior and posterior internal plexuses communicate via a series of venous rings - one near each vertebra.[3] Due to these interconnections, the anterior and posterior internal plexuses were formerly considered a single vascular unit - the retia venosa vertebrarum.[4]
The Batson venous plexus, which communicates the posterior intercostal vessels with the vertebral plexus, lacks valves so blood can flow in both directions. The clinical importance of this venous communication is that it represents an important phase in the establishment of vertebral metastases[6] and neuroschistomiasis.[7]
^Sinnatamby, Chummy S. (2011). Last's Anatomy (12th ed.). Elsevier Australia. p. 453. ISBN978-0-7295-3752-0.
^Brook RC, Tung K, Oeppen R. Batson’s plexus and retrograde venous spread of malignancy – a pictorial review. Cancer Imaging. 2014;14(Suppl 1):P40. Published 2014 Oct 9. doi:10.1186/1470-7330-14-S1-P40
^Carbonell C, Rodríguez-Alonso B, López-Bernús A, Almeida H, Galindo-Pérez I, Velasco-Tirado V, Marcos M, Pardo-Lledías J, Belhassen-García M. Clinical Spectrum of Schistosomiasis: An Update. J Clin Med. 2021 Nov 25;10(23):5521. doi: 10.3390/jcm10235521. PMID 34884223; PMCID: PMC8672275.