Superior mesenteric artery (SMA) syndrome arises from a reduction in the angle formed between the SMA and the aorta, thereby compressing the third portion of the duodenum. This phenomenon may be caused by a number of factors, one of which being acute weight loss. We report a case of a female patient presenting with abdominal pain and vomiting who developed superior mesenteric artery (SMA) syndrome as a result of rapid weight loss, thought to be secondary to amphetamine abuse. This association can often be overlooked and, to our knowledge, has not been previously reported.
The superior mesenteric artery (SMA) syndrome, also known as Cast Syndrome, Mesenteric Root Syndrome, or Wilke’s disease, is a rare cause of mechanical small intestinal obstruction and classically associated with rapid weight loss. SMA syndrome stems from compression on the third portion of the duodenum, resulting from the acute angle created between the superior mesenteric artery and the aorta, as caused by paucity of mesenteric and retroperitoneal fat pads. An illustration of this concept can be seen in Figure
A schematic view of the aorta, SMA, and third portion of the duodenum. (a) Loss of mesenteric fat producing an acute angle between aorta and SMA and compression of the duodenum. (b) Presence of mesenteric fat and a normal angle between aorta and SMA.
The patient being presented is a 30-year-old Asian-American female with a past medical history significant for Attention Deficit Hyperactivity Disorder (ADHD) and bipolar disorder and is prescribed a daily regimen of 10 mg amphetamine/dextroamphetamine. She presented with right upper quadrant and epigastric pain of 5 days’ duration. The pain was described as sharp, constant, and exacerbated by eating. It was associated with bilious, nonbloody vomiting, nausea, anorexia, and a thirty-pound weight loss over a time period of two months. The patient stated that she was under a significant amount of stress and she recently increased the dosage of her amphetamine/dextroamphetamine, the exact amount of which she was not able to specify. Examination revealed cachexia (BMI of 15.6) and right upper quadrant tenderness upon palpation. Abdominal CT scan (Figure
Contrast CT of the abdomen showing the distance between aorta and SMA (white arrow, marked as 3.6 mm). Also seen are a dilated stomach and duodenum and location of the SMA (black arrow).
Angiography of the abdominal aorta. The celiac and SMA branches are identified, as well as a narrow-angle formed between the abdominal aorta and the SMA branch.
Located in the retroperitoneum, the third portion of the duodenum runs through the acute angle created by the aorta and its branching artery known as the superior mesenteric artery [
The FDA approves the use of amphetamines for indications such as ADHD and narcolepsy; however, the off-label use and abuse of these drugs have grown to become a dangerous epidemic in the United States in recent years, most notably amongst young, college-aged individuals. Amphetamine abuse may involve acquisition from illicit sources or manipulation of legal doses, which we suspect led to our patient’s rapid weight loss and SMA syndrome. Amphetamine abuse may be difficult to recognize, and a patient’s history is oftentimes withheld. Therefore, when presented with a patient complaining of abdominal symptoms mimicking small bowel obstruction in the setting of rapid weight loss, one should consider the diagnosis of amphetamine-induced weight loss causing SMA syndrome.
The authors declare that there is no conflict of interests regarding the publication of this paper.