Title

Breaking the Vicious Cycle: A Case of Superior Mesenteric Artery Syndrome

Authors

Jiannan Huang¹, Maryam Sheikh², Joseph Schowalter³;

1 Internal Medicine, University of South Dakota Sanford School of Medicine, Sioux Falls, SD, United States.

2 Internal Medicine, Avera Medical Group, Sioux Falls, SD, United States

3 Gastroenterology, Avera Medical Group, Sioux Falls, SD, United States

Introduction

Superior mesenteric artery (SMA) syndrome is characterized by a vicious pathologic cycle (Figure 1) of aortomesenteric (AM) angle narrowing, duodenum compression leading to intractable vomiting, malnutrition, and further fat pad loss between aorta and SMA. It remains an underrecognized cause of vomiting. This clinical vignette presents a classic instance of SMA syndrome, aiming to enhance awareness of this condition.

Case Presentation

A 20-year-old female with a history of untreated depression, gastroesophageal reflux disease, and prior suicidal attempt, experienced intermittent abdominal pain, dyspepsia, and postprandial vomiting over 3 months. She presented to the emergency room with acute symptom exacerbation. Despite an 18-pound weight loss in a year, she had seen her primary care provider for “weight gain”. Physical examination revealed a slender build with a BMI of 19.1 kg/m², epigastric distension, and tenderness. Laboratory results showed normocytic anemia (Hemoglobin 11.8 g/dL) but otherwise nonrevealing blood counts, chemistry, urine, and stool studies. A computed tomography (CT) of the abdomen and pelvis showed a marked stomach distension (Figure 2A). The initial presentations and diagnostic workup suggested a gastric emptying disorder. She was hospitalized and received nasojejunal tube placement.

Subsequent esophagogastroduodenoscopy (EGD) revealed moderate extrinsic, traversable duodenal compression in the third part, characterized by pulsatile behavior. CT angiography confirmed a narrowed AM angle (19°) and AM distance (1.88 mm), establishing an SMA syndrome diagnosis (Figure 2B). Notably, her normal urinalysis suggested that she did not have co-existing Nutcracker syndrome. Conservative treatment, including gastrointestinal decompression, resulted in improvement and discharge with nutrition clinic follow-up.

The patient was re-hospitalized two weeks later due to severe vomiting, culminating in laparoscopic robotic-assisted duodenojejunal bypass surgery given the recurrence. Subsequently, a third admission occurred 6 weeks postoperatively due to a similar vomiting episode. An EGD revealed no stricture or narrowing of the anastomosis. The isolated event was attributed to gastroenteritis rather than treatment failure or complications. She recovered and gradually advanced her diet with multidisciplinary outpatient management by medical, surgical, vascular, psychiatric, and nutritional teams. At a 9-month follow-up, she maintained a stable condition, tolerating a regular diet with occasional nausea. Her BMI had increased to 21.9 kg/m².

Discussion

SMA syndrome, also called Wilkie's or cast syndrome, arises from SMA-aorta angle narrowing. It primarily affects young females (median age: 23 years)¹, often resulting from mesenteric adipose loss due to substantial weight reduction caused by dietary disorders, hypermetabolism (e.g., burns), or cachexia-inducing conditions such as malignancies or tuberculosis. Despite a notable incidence (10.8%) among patients with functional dyspepsia¹, delay in diagnosis is frequent, averaging 18 months². Imaging modalities like barium study, CT angiography, magnetic resonance imaging, and ultrasonography often lead to the diagnosis. Conservative management, including gastrointestinal decompression, boasts a 71.3% success rate³. Surgical intervention, including bypass or ostomy procedures, was pursued in ~17.5% of the patients³. SMA syndrome is a frequently overlooked cause of vomiting and weight loss in young adults and usually necessitates comprehensive multidisciplinary management. This case underscores the importance of promptly recognizing, diagnosing, and treating SMA syndrome to halt the vicious cycle of debilitating symptoms.

References

1. Oka A, et al. Superior mesenteric artery syndrome: Diagnosis and management. World J Clin Cases. 2023;11(15):3369-3384. doi:10.12998/wjcc.v11.i15.33692

2. Merrett ND, et al. Superior mesenteric artery syndrome: diagnosis and treatment strategies. J Gastrointest Surg. 2009;13(2):287-292. doi:10.1007/s11605-008-0695-4

3. Lee, T.H., Lee, J.S., Jo, Y. et al. Superior Mesenteric Artery Syndrome: Where Do We Stand Today? J Gastrointest Surg 16, 2203–2211 (2012). https://doi.org/10.1007/s11605-012-2049-5