Marginal artery of the colon
In human anatomy, the marginal artery of the colon, also known as the marginal artery of Drummond, the artery of Drummond, and simply as the marginal artery, is an artery that connects the inferior mesenteric artery with the superior mesenteric artery. It is sometimes absent, as an anatomical variant. Structure. The marginal artery runs in the mesentery close to the large intestine as part of the vascular arcade that connects the superior mesenteric artery and the inferior mesenteric artery. It provides an effective anastomosis between these two arteries for the large intestine. Variation. The marginal  artery is almost always present, and its absence should be considered a variant. Clinical significance. Removal of the inferior mesenteric artery. Along with branches of the internal iliac arteries, it is usually sufficiently large to supply the oxygenated blood to the large intestine. This means that the inferior mesenteric artery does not have to be re-implanted (re-attached) into the repaired abdominal aorta in abdominal aortic aneurysm repair. Arc of Riolan. The Arc of Riolan (Riolan's arcade, Arch of Riolan, Haller's anastomosis), also known as the meandering mesenteric artery, is another vascular arcade present in the colonic  mesentery that connect the proximal middle colic artery with a branch of the left colic artery. This artery is found low in the mesentery, near the root. In the setting of chronic ischemic colitis, both the marginal artery and the meandering mesenteric artery may be enlarged significantly, and may provide significant blood flow to the ischemic colonic segment. History. The marginal artery is also known as the marginal artery of Drummond.