Osmosis video - Superior mesenteric artery syndrome

Superior mesenteric artery syndrome (SMAS) is a condition caused by compression of the small intestine (jejunum) between the aorta and the superior mesenteric artery. It is a rare disorder, usually occurring in people who have lost a large amount of weight, including the initially present mesenteric fat. This causes the aortomesenteric angle to go from a normal 45-degree angle down to as little as 6 degrees. The result is small bowel obstruction which can cause early satiety and vomiting and can be corrected with weight gain, and in certain cases, surgery.