When symptoms of many GI disorders overlap, this can complicate a diagnosis. Nausea, vomiting, and abdominal bloating are vague clues that could point to any number of GI conditions, including SMA Syndrome.
What is SMA Syndrome?
SMA stands for superior mesenteric artery, which is a major blood vessel that supplies the small intestine, cecum, and colon. SMA Syndrome may also be known by several other names including, SMAS, Wilkie Syndrome, Cast Syndrome, arteriomesenteric duodenal obstruction, and chronic duodenal ileus. Whatever the name, this rare condition arises when the duodenum becomes compressed between the aorta and superior mesenteric artery. This often occurs as a result of dramatic weight loss and deterioration of the mesenteric fat pad that cushions the superior mesenteric artery. Other etiologies include, recent abdominal or spinal surgery, bedrest, use of body casts (hence, the name “Cast Syndrome”), or genetic predisposition.
Symptoms of SMA Syndrome mimic those of a small bowel obstruction. Individuals with SMA Syndrome may report nausea and vomiting, especially after meals, abdominal bloating, and early satiety. Lying prone or with knees to chest may help relieve symptoms. Diagnosis is made with radiographic evidence of a narrowed angle (less than 20°) between the aorta and superior mesenteric artery.
Nutrition implications of SMA Syndrome
The symptoms of SMA Syndrome—nausea, vomiting, early satiety—will likely interfere with nutritional intake. The nutritional impact of SMA Syndrome may vary between patients. Some individuals may be able to tolerate small, frequent meals or a liquid or soft diet. In contrast, other individuals may not be able to tolerate oral or gastric enteral feeding at all, in which case, nasojejunal feeding or parenteral nutrition may be needed.
Malnutrition may frequently be diagnosed alongside SMA Syndrome. When this is the case, nutrition interventions should begin early and be as aggressive as necessary, depending on the severity of malnutrition.
How dietitians can help
Given that SMA Syndrome often arises in patients who have experienced rapid, significant weight loss, a dietitian plays an integral role in recovery. Dietitians can offer customized medical nutrition therapy during the most acute phases of SMA Syndrome. If nutrition support is needed, dietitians can tailor the nutrition prescription to the patient’s specific needs. Full recovery and resolution of symptoms often includes weight gain to restore the mesenteric fat pad and widen the angle between the aorta and superior mesenteric artery. Dietitians can provide regularly scheduled follow ups and help clients set realistic goals to achieve healthy, sustainable weight gain.
Sara Glanz, MS, RD, LD, CNSC worked as a traveling dietitian for Dietitians On Demand for two years before joining the team as the corporate dietitian. In this role, she has championed the continuing education program to empower dietitians everywhere to achieve their professional goals.
International Foundation for Gastrointestinal Disorders. Superior mesenteric artery (SMA) syndrome. https://www.iffgd.org/other-disorders/sma-syndrome.html. Updated May 19, 2018. Accessed May 30, 2019.
NIH: National Center for Advancing Translational Sciences. Superior mesenteric artery syndrome. Genetic and Rare Diseases Information Center website. https://rarediseases.info.nih.gov/diseases/7712/superior-mesenteric-artery-syndrome. Updated February 20, 2017. Accessed May 30, 2019.