S3593 Superior Mesenteric Artery Syndrome: A Rare Cause of Gastrointestinal Obstruction

Abstract

INTRODUCTION: Superior mesenteric artery syndrome is an uncommon cause of proximal intestinal obstruction that occurs when the abdominal aorta and the superior mesenteric artery compress the distal part of the duodenum. It has been referred to by a variety of other names, including Cast Syndrome, Wilkie’s syndrome and duodenal vascular compression. Here we present the case of a 29-year-old female who was diagnosed with superior mesenteric artery syndrome refractory to conservative treatment. CASE DESCRIPTION/METHODS: The patient is a 29-year-old female with a medical history of generalized anxiety disorder and major depressive disorder who presented to the emergency department (ED) complaining of abdominal pain, nausea, and vomiting for 2 months. Abdominal pain was described as intermittent, sharp, located in the epigastric area, associated with nausea, non-bilious, non-bloody vomiting, bloating, and unintentional weight loss. On physical exam, the patient looked cachectic, with a tender abdomen. Initial workup was remarkable for hypokalemia and hypochloremia. Notable imaging included an abdominal X-ray showing a fluid-filled dilated stomach compatible with gastric outlet obstruction. A computed tomography (CT) scan of the abdomen and pelvis showed marked gastric dilatation with lesser dilatation of the first and second portion of the duodenum with narrowing or compression at the third and fourth portion and proximal jejunum. Additionally there was a decreased aorta mesenteric distance and angle, most likely compatible with a superior mesenteric artery (SMA) syndrome (Figure 1,2,3). The patient subsequently underwent esophagogastroduodenoscopy (EGD) that revealed copious amounts of retained bilious liquid and food material in the proximal stomach with no evidence of gastric outlet obstruction. There were no gross endoluminal lesions in the duodenum, but the sweep could not be traversed due to extrinsic compression likely secondary to SMA syndrome. The patient received adequate intravenous hydration and nasogastric tube (NGT) decompression with improvement of symptoms. After improvement of symptoms the patient left the hospital against medical advice and refused further evaluation. DISCUSSION: Superior mesenteric artery syndrome, although rare, should be considered as one of the differential diagnoses in the presence of partial or complete gastrointestinal obstruction. This can be successfully managed with conservatory measures, thus avoiding surgery which is reserved for refractory cases.Figure 1.: CT scan of the abdomen showing marked gastric dilation (blue arrows).Figure 2.: CT of the abdomen (axial view) showing decreased distance between the abdominal aorta (red arrow) and superior mesenteric artery (blue arrow) consistent with SMA syndrome.Figure 3.: CT of the abdomen (sagittal view) showing decreased distance between the abdominal aorta (red arrow) and superior mesenteric artery (blue arrow) consistent with SMA syndrome.