Compression of the duodenum between the aorta and the superior mesenteric artery can result in a obstruction of the passage in the horizontal duodenal segment with severe postprandial upper abdominal pain, vomiting, belching, nausea and can then lead to considerable weight loss. This clinical picture is referred to as superior mesenteric artery syndrome, SMA syndrome or Wilkie syndrome.
To diagnose this clinical picture, functional sonography is required during and after food intake, which shows that the food runs against the clamp of the aorta and superior mesenteric artery and the right-sided portion of the horizontal portion of the duodenum expands considerably, while the portion between the two arteries remains narrow. In typical cases, this should result in a configuration similar to that of a curved clamp.
Compression of the duodenum at high peristaltic pressure and even higher counterpressure of the vascular clamp from the aorta (bottom) and superior mesenteric artery (top)
This makes it clear that a strong driving force is pushing the duodenum against the clamp of the aorta and superior mesenteric artery, so that the duodenum is maximally dilated and yet is unable to widen the gap between the aorta and superior mesenteric artery sufficiently to ensure adequate transportation of food.
The diagnosis is often made when the angle between the aorta and the superior mesenteric artery is narrow.
In my many years of personal experience with many patients presenting with a suspected diagnosis of Wilkie syndrome, I must advise against relying on this angle sign.
For several reasons, this sign is completely unreliable:
At best, similar statements can be made with fluoroscopy after food intake. In this case, however, the arteries cannot be seen directly, the intestine is clearly visible as it is filled with high-contrast “food” (barium swallow). However, it can be shown whether there is a blockage in the right-sided portion of the horizontal duodenal segment. However, the examination is associated with radiation exposure, whereas the ultrasound examination is completely harmless and can use the food that causes the patient particular difficulties in real life.
Angle measurements are therefore unsuitable for detecting Wilkie syndrome.