Superior mesenteric artery syndrome is a rare digestive system disorder. The superior mesenteric artery provides blood to the small intestine, cecum, and colon. It crosses over the first part of the small intestine, called the duodenum. Symptoms occur when the artery obstructs the duodenum.
Superior mesenteric artery syndrome may be referred to at SMA Syndrome or as SMAS, and by a variety of other names including Cast syndrome, Wilkie syndrome, arteriomesenteric duodenal obstruction, and chronic duodenal ileus.
- abdominal fullness,
- bloating after meals,
- nausea and vomiting of partially digested food, and
- mid-abdominal “crampy” pain that may be relieved by the prone (lying on the stomach) or knee-chest position.
A number of factors may contribute to the syndrome, including:
- prolonged bed rest,
- weight loss,
- rapid growth,
- previous abdominal surgery,
- increased curvature in the lumbar portion of the spin (lordosis),
- use of body casts, and
- loss of tone in abdominal wall musculature.
The syndrome has also been reported in conjunction with pancreatitis, peptic ulcer, and other intra-abdominal inflammatory conditions.
Diagnosis of Superior Mesenteric Artery Syndrome
The diagnosis can be challenging because superior mesenteric artery syndrome is uncommon and symptoms can be nonspecific. Tests are done to differentiate the syndrome from other disorders that can cause similar clinical features.
Modern imaging techniques can provide noninvasive and detailed anatomic information that can be used in diagnosing the condition. Superior mesenteric artery syndrome is usually suspected based on signs and symptoms. A diagnosis can be confirmed by imaging studies such as an upper GI series (x-rays of the esophagus, stomach, and duodenum), hypotonic duodenography (an x-ray procedure that produces images of the duodenum), and computed tomography (CT scan).
Treatment typically focuses on addressing the underlying cause of the condition. For example, symptoms often improve by restoring lost weight with dietary or feeding strategies. Other medical strategies may be applied depending on individual circumstances.
Surgical options are rarely considered, ordinarily after other treatment strategies are tried but do not work. A multidisciplinary approach, including dieticians, can help with patient well-being before and after surgery.
Note: Many disorders can affect the digestive tract. Some can have symptoms that may be similar to or overlap with gastrointestinal (GI) functional or motility disorders. These will have uniquely identifying features which differentiate them from functional GI or motility disorders.
For More Information and Resources Relating to SMA Syndrome
Superior Mesenteric Artery Syndrome: Medscape Reference (free registration required)
National Institutes of Health (NIH), Genetic and Rare Diseases Information Center. (NIH webpage accessed December 13, 2016.)
Scovell S, Hamdan A. Superior mesenteric artery syndrome. Uptodate.com. (Webpage accessed October 1, 2017.) Access to complete article requires registration and, at minimum, a short-term subscription.