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Superior mesenteric artery syndrome

Other Names for this Disease
  • Arteriomesenteric duodenal compression syndrome
  • Cast syndrome
  • Vascular compression of the duodenum
  • Wilkie syndrome
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Your Question

I have been recently diagnosed with superior mesenteric artery syndrome. Can you provide me with information about this condition?

Our Answer

We have identified the following information that we hope you find helpful. If you still have questions, please contact us.

What is the superior mesenteric artery?

The superior mesenteric artery is a large artery in the abdominal cavity that provides blood to the small intestine, cecum, and colon. The small intestine is the portion of the digestive system most responsible for absorption of nutrients from food into the bloodstream.[1]  Click here to view a diagram of the superior mesenteric artery from the MERCK Manual Web site.

The superior mesenteric artery makes its way between two layers of the mesentery (membranous tissue which carries blood vessels and lymph glands and attaches organs to the abdominal wall) and crosses over the first part of the small intestine, called the duodenum.  The duodenum is where partly digested foods from the stomach mix with bile from the gall bladder and digestive juices from the pancreas.[2]

Last updated: 7/26/2012

What is superior mesenteric artery syndrome?

Superior mesenteric artery syndrome (SMAS) is a digestive condition that occurs when part of the duodenum (the first part of the small intestine) is compressed between the aorta and the superior mesenteric artery. This compression causes partial or complete obstruction of the duodenum.[3] 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 conditions inside the abdomen.[4] Treatment may include treating the underlying cause, and small feedings or a liquid diet.[4][3]
Last updated: 3/26/2014

What are the signs and symptoms of superior mesenteric artery syndrome?

Symptoms associated with superior mesenteric artery syndrome may include abdominal fullness, bloating after meals, nausea and vomiting of partially digested food, and mid-abdominal "crampy" pain that may be relieved by the prone or knee-chest position.[5]
Last updated: 7/26/2012

What causes superior mesenteric artery syndrome?

A variety of factors can contribute to the development of superior mesenteric artery syndrome (SMAS), including:
  • prolonged bed rest
  • rapid, severe weight loss
  • rapid growth
  • previous abdominal surgery
  • lordosis
  • use of body casts
  • loss of tone in abdominal muscles

SMAS has also been reported to occur in some people with pancreatitis, peptic ulcers, and other inflammatory conditions in the abdomen.[5] Rarely, the condition may be caused by an anatomical abnormality (such as unusual position or location of the artery). Familial SMAS, recurrent SMAS, and idiopathic neonatal SMAS have also been reported.[3]

Last updated: 3/26/2014

How might superior mesenteric artery syndrome be treated? 

In cases of acute superior mesenteric artery syndrome (SMAS), treatment typically focuses on removing or stopping the underlying cause of the condition.[3] For example, symptoms often improve after lost weight is restored or a body cast is removed.[6] Treatment in most cases is conservative at first and may involve adequate nutrition, nasogastric decompression (a tube passed through the nose into the stomach), and proper positioning after eating (such as lying prone and knee-to-chest position). In some cases, both enteral and parenteral nutritional support may be needed to provide enough calories.[3]

Affected people can usually then be started on oral liquids, followed by slow and gradual introduction of small and frequent soft meals as tolerated. Then, regular solid foods may be introduced. Metoclopramide treatment may be beneficial for some people.[3]

Surgery may be needed when conservative treatment doesn't work, particularly in people with a long history of progressive weight loss, pronounced duodenal dilatation with stasis, and peptic ulcer disease. However, people should generally try conservative treatment for at least 4-6 weeks before considering surgery.[3]
Last updated: 3/26/2014

  • Small Intestine. MedlinePlusMedical Encyclopedia. November 8, 2010; Accessed 7/26/2012.
  • Duodenum. MedlinePlus Medical Encyclopedia. October 30, 2010; Accessed 7/26/2012.
  • Frederick Merrill Karrer. Superior Mesenteric Artery Syndrome. Medscape Reference. September 4, 2012; Accessed 3/26/2014.
  • Superior Mesenteric Artery (SMA) Syndrome. International Foundation for Functional Gastrointestinal Disorders. January 17, 2013; Accessed 3/26/2014.
  • Juan-R. Malagelada, Carolina Malagelada . Chapter 8 - Nausea and Vomiting. In: Mark Feldman, Lawrence S. Friedman, Lawrence J. Brandt. Sleisenger & Fordtran's Gastrointestinal and Liver Disease, 8th edition. Philadelphia, PA : Saunders Elsevier; 2006;
  • Lawrence J Brandt. Chapter 35 - Vascular Lesions of the Gastrointestinal Tract. In: Mark Feldman, Lawrence S. Friedman. Sleisenger & Fordtran's Gastrointestinal and Liver Disease, 8th edition. Philadelphia, PA: Saunder Elsevier; 2006;