Because of its embryologic development from both the midgut and hindgut, the colon has two main sources of blood supply: the superior mesenteric (1) and the inferior mesenteric arteries (2). The superior mesenteric artery (1) supplies the right colon, the appendix, and small intestine. The middle colic artery (3) is the most prominent branch of the superior mesenteric artery. It arises after the pancreaticoduodenal vessels (see Chapter 5). The middle colic artery branches into a right and left division. The right division anastomoses with the right colic (4) and the ileocolic (5) arteries. The left branch communicates with the marginal artery of Drummond (6). The middle and right colic and ileocolic arteries are doubly ligated near their origin when a right colectomy is performed for malignancy. The ileocolic artery reaches the mesentery of the appendix from beneath the terminal ileum. Angulation or obstruction of the terminal ileum should be avoided following the ligation of the appendiceal artery (7) in the presence of a short mesentery.

The inferior mesenteric artery arises from the aorta just below the ligament of Treitz. Its major branches include the left colic (8), one or more sigmoid branches (9, 10), and the superior hemorrhoidal artery (11). Following ligation of the inferior mesenteric artery at its origin, the viability of the colon is maintained through the marginal artery of Drummond (6) by way of the left branch of the middle colic artery.