Teaching Case

A 30-year-old male patient was admitted to the emergency department with postprandial epigastric and right-upper-quadrant pain associated with nausea. Medical history revealed a recent rapid weight loss (10 kg in the past two months) and a current body mass index (BMI) of 23.4. He had no past history of abdominal surgery.

On physical examination the patient was in pain and appeared quite uncomfortable. His symptoms were relieved by lying in the left lateral side or by acquiring a knee-chest position (Fig. 1). He was dehydrated and afebrile. The abdomen was soft with mild discomfort on palpation at the epigastric area but with no rebound or rigidity tenderness. Laboratory tests including complete blood count, liver and kidney function tests were normal. Ultrasonography demonstrated a hyperactive duodenum, a left-sided inferior vena cava (IVC) and a narrowed angle between the superior mesenteric artery and the aorta (Fig. 2, 3). No free intraperitoneal fluid was detected. Therefore, the diagnosis of superior mesenteric artery syndrome was suggested and was further confirmed with an upper gastrointestinal fluoroscopic examination and a contrast-enhanced computed tomography (Fig. 4-6). The patient was treated conservatively with intravenous fluid and electrolyte replacement and was discharged on the third day in stable condition.

Wilkie's syndrome or superior mesenteric artery syndrome is a rare aetiology of intestinal obstruction resulting from the compression of the third part of the duodenum between the superior mesenteric artery (SMA) and the aorta [1-2].The syndrome was first observed in 1842 by von Rokitansky, but was reported later in 1927 by Wilkie [1-3]. The SMA arises normally from the abdominal aorta at a 25°-60° angle and is surrounded by fatty tissue that protects the duodenum from compression [3]. Severe weight loss results in loss of the mesenteric fat pad and the SMA may compress the duodenum. The most common causative factors that result in an acute aorto-SMA angle and may predispose to duodenal mechanical obstruction are: i) Rapid weight loss (as in malignancy, severe burns, malabsorption syndromes and eating disorders: anorexia nervosa and bulimia nervosa), ii) Congenital short or high fixed ligament of Treitz and iii) Spinal deformity-trauma/scoliosis correction surgery [2-4]. Patients may present with acute or chronic forms of duodenal obstruction and symptomatology usually includes intermittent nausea and postprandial abdominal distention-epigastric pain. In severe cases of duodenal obstruction epigastralgia may be followed by vomiting. The differential diagnosis should be made from more common causes of small bowel obstruction such as adhesions, hernias and tumours. Cross sectional examinations with its multiplanar capabilities can evaluate the aortomesenteric angle and provide the clue for the correct diagnosis [5, 6]. An upper gastrointestinal fluoroscopic examination remains a valuable imaging tool because it can show the dilation of the first and second portions of the duodenum and the abrupt compression of the third portion (“cut-off sign”). Conservative treatment is indicated initially in Wilkie's syndrome and includes fluid and electrolyte replacement, total parenteral nutrition and nasogastric decompression in cases of gastric dilation [7]. The reversal of predisposing factors is of paramount importance and the patients are encouraged to restore their normal body weight. In our case, although the patient had a normal BMI, the recent rapid weight loss was the precipitating cause of the syndrome. He is currently under a normal caloric diet in order to regain weight. In cases of conservative treatment failure the syndrome can be treated surgically by means of duodenojejunostomy, gastrojejunostomy or a Roux-en-Y procedure [3-4, 8]. All the aforementioned techniques create a bypass route but are reserved only for the severe forms of the syndrome and providing that conservative treatment measures have failed.