Superior mesenteric artery syndrome
(SMAS) is a digestive condition that occurs when the duodenum (the first part of the small intestine) is compressed between two arteries (the aorta and the superior mesenteric artery). This compression causes partial or complete blockage of the duodenum. Signs and symptoms may include abdominal fullness; bloating after meals; nausea and vomiting; and abdominal cramping that may be helped by lying in certain positions. A variety of factors may contribute to SMAS, including prolonged bed rest, weight loss, rapid growth, previous abdominal surgery, lordosis, use of body casts, and loss of tone in abdominal muscles. It may also occur with pancreatitis, peptic ulcers, and other inflammatory abdominal conditions. Treatment may include addressing the underlying cause and/or dietary modifications (small feedings or a liquid diet). Source: Genetic and Rare Diseases Information Center (GARD), supported by ORDR-NCATS and NHGRI.