Arteria sacralis mediana
The median sacral artery is a small single posterior branch of the distal abdominal aorta that descends to supply structures in the pelvis.
Summary
- location: abdomen and pelvis
- origin and termination: originates as a posterior branch of the distal abdominal aorta just above the level of the bifurcation; terminates in the coccygeal body
- supply: L4 and L5, sacrum, coccyx and superoposterior rectum (minor)
- relations: anterior to the L4 and L5 vertebrae, sacrum and coccyx; posterior to the left common iliac vein
Gross anatomy
Origin
The median sacral artery arises as a small single posterior branch of the distal abdominal aorta just above the level of the bifurcation into right and left common iliac arteries (L4 level).
Course
It descends roughly in the midline anterior to L4 and L5 vertebral bodies, then over the sacral promontory and down towards the coccyx.
Termination
The median sacral artery terminates by tapering off in the coccygeal body
Branches
- anastomoses with the lumbar branch of the iliolumbar artery and lateral sacral arteries
- tiny branches to the rectum
Supply
The median sacral artery contributes to the arterial supply of the 4th and 5th lumbar vertebrae, sacrum, coccyx and superoposterior rectum (minor contribution).
Relations
- anterior to the L4 and 5 vertebrae, sacrum and coccyx
- posterior to the left common iliac vein
- accompanied (typically on the right) by the median sacral vein
Variant anatomy
The median sacral artery may give rise to a fifth lumbar artery.