Etiology of Acute Mesenteric Ischemia Three major vessels serve the abdominal contents: Celiac trunk: Supplies the esophagus, stomach, proximal duodenum, liver, gallbladder, pancreas, and spleen Superior mesenteric artery (SMA): Supplies the distal duodenum, jejunum, ileum, and colon to the splenic flexure Inferior mesenteric artery (IMA): Supplies the descending colon, sigmoid colon, and rectum Collateral vessels are abundant in the stomach, duodenum, and rectum; these areas rarely develop ischemia.