Middle rectal artery
The middle rectal artery, also called the middle hemorrhoidal artery, or middle anorectal artery, is an inconsistent branch of the anterior division of the internal iliac artery which supplies the rectum. It is found in the lesser pelvis, running within the lateral fascial coverings of the mesorectum.
Upon reaching the rectum, it splits into smaller branches and which supply the muscles of the middle and lower parts of the rectum.
This article will discuss the anatomy and function of the middle rectal artery.
|Origin||Internal iliac artery|
|Branches||Rectal, prostatic, seminal, vaginal branches|
|Supply||Middle and lower parts of the rectum; prostate, seminal vesicles, vagina|
Origin and course
The middle rectal artery usually arises from the anterior division of the internal iliac artery and courses inferiorly across the lesser pelvis, and enters the mesorectum.
They are ensheathed by fascia along with the branches of the inferior hypogastric plexus and are sometimes together referred to as the ‘lateral rectal ligaments’.
The middle rectal artery then continues vertically, before taking a 90° turn to transversely approach the lower rectum, where it splits into several terminal branches.
Branches and supply
The middle rectal artery gives off terminal branches forming weak anastomoses with the superior and inferior rectal arteries, as well as the median sacral artery. The branches of the middle rectal artery supply the middle and lower portions of the rectum.
In addition, the middle rectal artery occasionally gives rise to several other arteries, such as vaginal branches in females which supply the vagina, prostatic and seminal branches in males supplying the prostate and seminal vesicles, and rarely an inferior lateral sacral branch.
The middle rectal artery is highly inconsistent. It is variably present, with studies suggesting it is more commonly present in males than females. When present, it is more often unilateral than bilateral and it often has a variable point of origin. On the other hand, it can occasionally be found in duplicates and more. The middle rectal artery can arise as a common trunk with the uterine, inferior vesical, internal pudendal, or inferior gluteal arteries.