The left colic artery is a branch of the

inferior mesenteric artery In human anatomy, the inferior mesenteric artery (IMA) is the third main branch of the abdominal aorta and arises at the level of L3, supplying the large intestine from the distal transverse colon to the upper part of the anal canal. The region ...

distributed to the

descending colon In the anatomy of humans and homologous primates, the descending colon is the part of the colon extending from the left colic flexure to the level of the iliac crest (whereupon it transitions into the sigmoid colon). The function of the descen ...

, and left part of the

transverse colon In human anatomy, the transverse colon is the longest and most movable part of the Large intestine#Structure, colon. Anatomical position It crosses the abdomen from the ascending colon at the right colic flexure (hepatic flexure) with a downward ...

. It ends by dividing into an ascending branch and a descending branch; the terminal branches of the two branches go on to form anastomoses with the middle colic artery, and a sigmoid artery (respectively).

Structure

The left colic artery usually represents the dominant arterial supply to the left colic flexure.

Course

The left colic artery passes to the left posterior to the

peritoneum The peritoneum is the serous membrane forming the lining of the abdominal cavity or coelom in amniotes and some invertebrates, such as annelids. It covers most of the intra-abdominal (or coelomic) organs, and is composed of a layer of mesotheli ...

. After a short but variable course, it divides into an ascending branch and a descending branch.

Branches and anastomoses

Ascending branch

The ascending branch passes superior-ward. It passes anterior to the (ipsilateral) psoas major muscle, gonadal vessels,

ureter The ureters are tubes composed of smooth muscle that transport urine from the kidneys to the urinary bladder. In an adult human, the ureters typically measure 20 to 30 centimeters in length and about 3 to 4 millimeters in diameter. They are lin ...

, and

kidney In humans, the kidneys are two reddish-brown bean-shaped blood-filtering organ (anatomy), organs that are a multilobar, multipapillary form of mammalian kidneys, usually without signs of external lobulation. They are located on the left and rig ...

; it passes posterior to the

inferior mesenteric vein In human anatomy, the inferior mesenteric vein (IMV) is a blood vessel that drains blood from the large intestine. It usually terminates when reaching the splenic vein, which goes on to form the portal vein with the superior mesenteric vein (SMV) ...

. Its terminal branches form anastomoses with those of the middle colic artery; it also forms anastomoses with the descending branch (of the left colic artery).

Descending branch

The descending branch passes inferolaterally. It forms anastomoses with the superior-most sigmoid artery as well as the ascending branch (of the left colic artery), thereby participating in the formation of the marginal artery of the colon.

Variation

The left colic artery may have a common origin with a sigmoid artery, or may arise by branching of from a sigmoid artery. Occasionally, the left colic artery may arise from either the superior mesenteric artery, the middle colic artery, or the proximal-most jejunal artery; rarely, an accessory left colic artery may arise from the aforementioned arteries. An accessory left colic artery may also arise from the left colic artery itself.

Clinical significance

The left colic artery may be ligated during

abdominal surgery The term abdominal surgery broadly covers surgical procedures that involve opening the abdomen (laparotomy). Surgery of each abdominal organ is dealt with separately in connection with the description of that organ (see stomach, kidney, liver, e ...

to remove

colorectal cancer Colorectal cancer (CRC), also known as bowel cancer, colon cancer, or rectal cancer, is the development of cancer from the Colon (anatomy), colon or rectum (parts of the large intestine). Signs and symptoms may include Lower gastrointestinal ...

. This may have poorer outcomes than preserving the artery.

Additional images

File:Gray1041.png, Superior and inferior duodenal fossæ. File:Gray1042.png, Duodenojejunal fossa.

References

External links

Lotti M. Anatomy in relation to left colectomy
* * - "Intestines and Pancreas: Branches of the Inferior Mesenteric Artery" * * Arteries of the abdomen {{circulatory-stub pt:Artéria cólica direita