The lateral sacral artery is one of three branches of the posterior division of the internal iliac artery.

Summary

• location: pelvis
• origin: from the posterior division of the internal iliac artery in the pelvis
• branches: superior and inferior sacral arteries
• supply: sacral meninges, piriformis muscle, erector spinae muscles, cutaneous area over sacrum

Gross anatomy

Origin

The lateral sacral artery originates from the posterior division of the internal iliac artery.

Course

It proceeds inferiorly, in close relation to the roots of the sacral plexus. It lies just lateral to the anterior sacral foramina and usually splits into superior and inferior branches, which supply 2 foramina each.

Branches

The superior branch passes medially, often anastomoses with the middle sacral artery and enters S1 and S2 foramina. It enters and supplies the sacral meninges and exits posteriorly to supply erector spinae and the cutaneous area over the sacrum, and anastomoses with the superior gluteal artery.

The inferior branch passes inferomedially over the piriformis muscle and runs down toward the coccyx, where it anastomoses with the middle sacral artery. It passes through the S3 and S4 foramina to supply spinal meninges and exits to supply muscle and overlying skin posteriorly.

Supply

The superior branch supplies the upper two sacral foramina and contents, erector spinae, and cutaneous supply over the sacrum.

The inferior branch supplies the lower two sacral foramina and contents as well as the piriformis muscle, coccyx, erector spinae, and skin over the sacrum.

Variant anatomy

Occasionally the superior and inferior sacral vessels may not stem from the lateral sacral artery. Instead, they may directly come from the internal iliac artery.

Related pathology

Sacral fractures may lead to lateral sacral artery injury due to the close relationship between the sacrum and this vasculature.