Left colic artery
The left colic artery is a branch of the inferior mesenteric artery. Structure. It runs to the left behind the peritoneum and in front of the psoas major muscle. After a short, but variable, course, it divides into an ascending and a descending branch. The stem of the artery or its branches cross the left ureter and left internal spermatic vessels. The ascending branch crosses in front of the left kidney and ends, between the two layers of the transverse mesocolon, by anastomosing with the middle colic artery; the descending branch anastomoses with the highest sigmoid artery . From the arches formed by these anastomoses branches are distributed to the descending colon and the left part of the transverse colon. Clinical significance. The left colic artery may be ligated during abdominal surgery to remove colorectal cancer. This may have poorer outcomes than preserving the artery.