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Lateral sacral vein

The lateral sacral vein is a paired venous structure that accompanies the lateral sacral artery along the anterior surface of the sacrum. It collects venous blood from the sacral region and communicates with surrounding venous plexuses. The veins drain into the internal iliac vein, playing an important role in pelvic venous return and venous anastomoses.

Clinically, the lateral sacral veins are relevant in pelvic surgery, trauma, and oncology because they connect with the internal vertebral venous plexus, providing a potential route for metastatic spread to the spine.

Synonyms

  • Sacral lateral vein

  • Veins of the sacrum (lateral group)

  • Lateral sacral venous plexus

Origin, Course, and Tributaries

  • Origin: Arises from venous tributaries on the anterior surface of the sacrum and sacral foramina

  • Course:

    • Runs vertically along the lateral side of the sacrum, accompanying the lateral sacral artery

    • Receives tributaries from the sacral spinal veins, muscles, and adjacent venous plexuses

    • Communicates with the internal vertebral venous plexus through the intervertebral foramina

  • Termination: Empties into the internal iliac vein

  • Tributaries:

    • Venous branches from sacral canal and sacral foramina

    • Connections from presacral and sacral venous plexuses

Relations

  • Anteriorly: Sacral bodies and presacral fascia

  • Posteriorly: Sacral canal and spinal venous plexuses

  • Laterally: Internal iliac vein and pelvic viscera

  • Medially: Sacral foramina and communicating venous channels

Function

  • Drains venous blood from the sacral region, sacral spinal canal, and posterior pelvis

  • Provides a major connection between pelvic venous plexuses and the vertebral venous system

  • Plays a role in maintaining collateral venous circulation in the pelvis

Clinical Significance

  • Metastatic spread: Provides a pathway for tumor cells to spread between pelvic organs and the vertebral column

  • Surgical relevance: May cause significant bleeding if injured during pelvic or spinal surgery

  • Trauma: Can be a source of hemorrhage in pelvic fractures

  • Venous congestion: May participate in pelvic venous disorders or presacral venous varices

MRI Appearance

T1-weighted images:

  • Vein lumen shows low signal intensity when patent

  • Thrombosed vein may show intermediate to high signal intensity depending on clot age

  • Surrounding fat: bright, outlining the vessel course

T2-weighted images:

  • Flowing blood appears as signal void (dark linear channel)

  • Slow flow or dilatation may appear with bright intraluminal signal

  • Surrounding fat: moderately bright

STIR (Short Tau Inversion Recovery):

  • Vein lumen usually suppressed and dark (if flow present)

  • Thrombosis or inflammatory changes may appear as bright hyperintensity

  • Fat around vein: suppressed (dark), enhancing contrast of vessel walls

T1 Fat-Sat Post-Contrast:

  • Patent vein enhances with contrast, showing a bright lumen

  • Thrombosed segments fail to enhance

  • Perivenous inflammation or tumor invasion may enhance heterogeneously

CT Appearance

Non-Contrast CT:

  • Veins appear as soft tissue density channels along sacrum

  • Thrombosis: appears as hyperdense intraluminal filling

  • Surrounding fat planes clearly define venous channels

Post-Contrast CT:

  • Patent veins enhance and opacify with contrast

  • Thrombosed veins remain unenhanced

  • Dilated veins/varices appear as tortuous enhancing channels

  • Tumor or inflammatory involvement may present as perivenous soft tissue thickening

MRI image

Lateral sacral vein mri axial anatomy image-img-00000-00000

MRI image

Lateral sacral vein mri axial anatomy image-img-00000-00000_00001

MRI image

Lateral sacral vein mri coronal anatomy image-img-00000-00000

MRI image

Lateral sacral vein mri coronal anatomy image-img-00000-00000_00001