The following information may help to address your question:
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.
The superior mesenteric artery arises from the aorta and is enveloped in fatty and lymphatic tissue (mesenteric pad). It forms an angle of about 38 º and 65º with the abdominal aorta (due in part, to the mesenteric fat pad). Because the third part of the duodenum courses between the angle formed by the superior mesenteric artery and aorta, any factor that sharply narrows the angle between the aorta and superior mesenteric artery can cause entrapment and compression of the third part of the duodenum resulting in superior mesenteric artery syndrome. This angle correlates with body mass index.
A variety of factors can contribute to the narrowing of the aorto-mesenteric angle:
There are some reports about more than one case in the same family and one report about affected identical twins, which suggests a genetic predisposition in some patients.
There are also several reported cases of superior mesenteric artery syndrome associated with celiac axis compression syndrome.
Treatment for superior mesenteric artery syndrome typically focuses on addressing the underlying cause of the condition. For example, symptoms often improve after lost weight is restored or a body cast is removed. Nasogastric decompression (a tube passed through the nose into the stomach) and proper positioning after eating (such as lying in the left side or standing or sitting with a knee-to-chest position) may be recommended to alleviate symptoms.
In severe cases, intravenous (IV) nutritional support and/or a feeding tube may be needed to provide enough calories. 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 to avoid vomiting may be beneficial for some people.
Surgery may be needed if other treatment strategies do not work. However, other treatment options should usually be tried for at least 4-6 weeks before considering surgery.
Surgery options are: