Topics

Topic

design image
Vertebral venous plexus

The vertebral venous plexus is an extensive, valveless venous network located within and around the vertebral column. It serves as a major pathway for venous drainage of the spine and provides important collateral circulation between the pelvis, thorax, and cranial cavity. The system is clinically important because it may act as a conduit for the spread of infection and metastasis, particularly to the spine and skull base.

This plexus is divided into internal and external components, both interconnected and communicating with systemic venous systems.

Synonyms

  • Spinal venous plexus

  • Batson’s plexus

  • Epidural venous plexus

Location and Pathways

  • Internal vertebral venous plexus:

    • Lies within the vertebral canal, in the epidural space, surrounding the dura mater

    • Runs longitudinally along the vertebral bodies and posterior elements

  • External vertebral venous plexus:

    • Located on the outer surfaces of the vertebral column (anterior and posterior to vertebral bodies and arches)

  • Connections:

    • Communicates superiorly with the cranial dural venous sinuses

    • Communicates inferiorly with the pelvic venous plexuses

    • Laterally communicates with segmental veins (intercostal, lumbar, sacral veins)

Relations

  • Anteriorly: Vertebral bodies and intervertebral discs

  • Posteriorly: Vertebral laminae and ligamentum flavum

  • Laterally: Pedicles and intervertebral foramina (communicating with segmental veins)

  • Medially: Dura mater and spinal cord (for internal plexus)

Function

  • Provides venous drainage of the vertebral column, spinal cord, and meninges

  • Acts as a valveless collateral pathway, allowing bidirectional blood flow

  • Balances venous return between cranial, thoracic, abdominal, and pelvic regions

  • Serves as a pressure-regulating network during changes in posture, coughing, or straining

Clinical Significance

  • Metastasis pathway: Provides a route for spread of pelvic/abdominal malignancies (e.g., prostate, breast, kidney) to spine and brain without passing through lungs

  • Infections: Acts as a conduit for spread of pelvic/abdominal infections to spinal canal

  • Epidural venous engorgement: Seen in increased intra-abdominal/intrathoracic pressure (e.g., pregnancy, IVC obstruction)

  • Spinal surgery relevance: Prominent epidural veins may cause bleeding during laminectomy or discectomy

MRI Appearance

T1-weighted images:

  • Venous plexus shows as flow voids (dark signal channels) in normal fast-flowing veins

  • Slow flow or thrombosed segments may appear as intermediate-to-bright signal

T2-weighted images:

  • Normal plexus shows signal voids due to flow

  • Slow or stagnant flow may appear bright hyperintense

  • Enlarged veins may appear as serpiginous structures within epidural space

T1 Fat-Sat Post-Contrast:

  • Plexus enhances strongly and uniformly after contrast

  • Distended epidural veins appear as enhancing serpiginous channels

  • Thrombosed veins may enhance irregularly or show no enhancement centrally

3D T2 SPACE / CISS:

  • Venous plexus appears as flow void tubular channels within epidural fat

  • Excellent sequence for showing relationship to traversing/exiting nerve roots and thecal sac

  • Enlarged or varicose epidural veins displace adjacent structures

CT Appearance

Non-Contrast CT:

  • Plexus usually not seen unless markedly enlarged

  • Appears as soft tissue density along epidural or paravertebral regions

  • Phleboliths (calcifications) may rarely be seen in chronic venous changes

Post-Contrast CT:

  • Enhancing tubular/serpiginous channels along vertebral canal and paravertebral areas

  • Prominent in venous engorgement or collateral circulation (e.g., IVC obstruction, pelvic tumor spread)

MRI image

Vertebral venous plexus mri axial anatomy image-img-00000-00000

MRI image

Vertebral venous plexus mri sag anatomy image-img-00000-00000