SMAS (superior mesenteric artery syndrome) is a highly rare digestive condition that presents when the superior mesenteric artery causes an obstruction of the small intestine, specifically the duodenum. This obstruction is often caused when the artery bends at an unnatural angle, compressing the duodenum against the heart’s aorta. SMAS can lead to a variety of symptoms that share many similarities with other gastrointestinal disorders; in addition, the obstruction can present as intermittent or chronic, making SMAS extremely hard to diagnose. Rather than being diagnosed directly, SMAS is often diagnosed via the process of elimination of other, more common digestive disorders.
Other Names Commonly Used for Superior Mesenteric Artery Syndrome:
- Wilkie syndrome
- Arteriomesenteric duodenal compression
- Chronic duodenal ileus
- Cast syndrome
Causes of SMAS
The SMA and duodenum are separated by a cushion of fatty tissue that normally acts as a buffer, preventing the SMA from causing any obstructions to the small intestine. However, certain situations can lead to that cushion being reduced, such as sudden weight loss or an increase in body height without a corresponding weight increase. When the cushion is reduced, it can lead to a shift in the position of the SMA, changing its natural angle and causing it to press against the duodenum, resulting in a blockage.
SMAS is also a common complication that arises from patients who are recovering from scoliosis or spinal surgery, or any condition that requires a body cast to be utilized. These casts, while vital to the recovery process, can sometimes add external pressure to the body that affects the small intestine.