Left colic arteryThe left colic artery is a branch of the inferior mesenteric artery that supplies the distal thirds of the transverse colon. It courses retroperitoneally behind the left colic mesentery until it bifurcates into an ascending and descending branch.
The branches of the left colic artery anastomose with branches of the middle colic and sigmoid arteries and contribute to the formation of the marginal artery of Drummond, an arterial channel that supplies the large intestine.
|Origin||Inferior mesenteric artery|
|Branches||Ascending and descending branch|
|Supply||Distal third of the transverse colon|
The left colic artery is a branch of the inferior mesenteric artery, arising shortly after its origin from the aorta. It courses upwards posterior to the left colic mesentery and crosses over the anterior surface of the left psoas major muscle, left ureter and gonadal vessels.
Branches and supply
After completing its course, the left colic artery divides into its terminal branches; the ascending and descending branch.
- Ascending branch: courses superiorly, anterior to the left kidney and then enters the transverse mesocolon. In the area of the splenic flexure, the ascending branch of the left colic artery anastomoses with the left branch of the middle colic artery, which arises from the superior mesenteric artery. This anastomosis is called the arcade of Riolan, which signifies a direct communication between the superior and inferior mesenteric arteries. This communication is significant to provide collateral blood flow in the event of a stenosis and occlusion.
- Descending branch: courses laterally in the retroperitoneum towards the descending colon, where it anastomoses with one of the sigmoid arteries, thereby contributing to the formation of the marginal artery of Drummond.