Descending branch of left colic artery

At a glance

English

Descending branch of left colic artery

Latin (TA2)

Ramus descendens arteriae colicae sinistrae

System

Artery

Region

Trunk

Side

Single, on the midline

About the descending branch of left colic artery

Soon after it leaves the inferior mesenteric artery, the left colic artery divides on the posterior abdominal wall. One branch climbs towards the splenic flexure; the other, the descending branch, turns downwards along the left side of the abdomen to supply the lower descending colon.

The descending branch runs behind the parietal peritoneum, on the left posterior wall, towards the left iliac fossa. Along its way it sends small vessels into the descending colon and lower down it joins the uppermost sigmoid artery, another branch of the inferior mesenteric artery. Through this junction it forms part of the marginal artery, the line of anastomosing vessels along the mesenteric edge of the colon from which short straight arteries pass into the bowel wall.

The descending colon is fixed to the back wall without a mesentery, so the artery and its branches reach the bowel through the loose tissue behind the peritoneum. In left-sided colon surgery the vessel is divided with the left colic artery, and the surgeon relies on the marginal artery to carry blood along the remaining bowel.

If the origin of the inferior mesenteric artery is narrowed or blocked, as can happen with disease of the aorta, the left colon can still stay perfused, because the descending branch and the marginal artery receive blood from the superior mesenteric side above and from the rectal vessels below.

Course and supply

Arises from

The left colic artery, at its division into ascending and descending branches on the posterior abdominal wall.

Ends in

Ends by anastomosing with the highest sigmoid artery and joining the marginal artery of the colon.

Supplies

Supplies the lower part of the descending colon.