Can a nearly blocked superior mesenteric artery cause chronic nausea?

Superior Mesenteric Artery Stenosis Can Cause Chronic Nausea

Yes, a nearly blocked superior mesenteric artery (SMA) can cause chronic nausea as part of chronic mesenteric ischemia syndrome. This occurs when there is insufficient blood flow to the intestines due to arterial stenosis, leading to a constellation of symptoms including nausea.

Pathophysiology and Clinical Presentation

Chronic mesenteric ischemia (CMI) occurs when there is significant narrowing or blockage of the mesenteric arteries, most commonly the superior mesenteric artery. The European Society of Cardiology (ESC) guidelines describe the classic clinical presentation:

• Patients with mesenteric artery disease typically present with "abdominal angina," characterized by painful abdominal cramps and colic occurring in the post-prandial phase 1
• Nausea is a prominent feature of what is called "ischemic gastropathy," along with vomiting, diarrhea, malabsorption, and unintended progressive weight loss 1
• Food aversion develops as patients learn to associate eating with pain 1

Diagnostic Approach

When chronic nausea is suspected to be related to SMA stenosis, the following diagnostic approach is recommended:

1. Initial Imaging: CT angiography (CTA) of the abdomen and pelvis is the recommended first-line diagnostic test with sensitivity and specificity of 95-100% 2

2. Duplex Ultrasound (DUS): The ESC guidelines indicate that DUS has become the imaging method of choice for initial evaluation of mesenteric artery disease 1

   • The diagnostic performance may be improved by a post-prandial test
   • Should be performed in specialized centers by experienced technicians

3. Additional Imaging: When DUS is inconclusive, CTA or gadolinium-enhanced MRA are indicated 1

Clinical Clues Suggesting SMA Stenosis as Cause of Nausea

The following factors increase the likelihood that chronic nausea is related to SMA stenosis:

• Postprandial timing of symptoms (particularly nausea occurring after meals)
• Weight loss due to food aversion
• Other atherosclerotic risk factors (hypertension, diabetes, smoking, hypercholesterolemia) 1
• History of other atherosclerotic diseases (coronary artery disease, peripheral artery disease)
• Abdominal bruit on physical examination 1

Management Considerations

If SMA stenosis is confirmed as the cause of chronic nausea:

1. Revascularization: For symptomatic patients, revascularization should not be delayed 1

   • Endovascular therapy (angioplasty and stenting) has become the first-line approach in most centers 1
   • Open surgical bypass offers improved patency and lower re-intervention rates but higher initial risk 1

2. Risk Factor Modification:

   • Smoking cessation is essential
   • Management of hypertension, diabetes, and hypercholesterolemia

Important Considerations

• Severity of Stenosis: Symptoms typically develop when at least two of the three main mesenteric vessels (celiac trunk, SMA, inferior mesenteric artery) are affected 1

• Differential Diagnosis: Other conditions that can cause similar symptoms include:

  • Superior mesenteric artery syndrome (compression of duodenum between SMA and aorta) 3, 4, 5, 6, 7
  • Non-occlusive mesenteric ischemia 1
  • Median arcuate ligament syndrome 1

• Progression Risk: Untreated symptomatic mesenteric artery disease can lead to starvation, bowel infarction, and death 1, 2

Conclusion

When evaluating a patient with chronic nausea, particularly when associated with postprandial abdominal pain and weight loss, SMA stenosis should be considered in the differential diagnosis. Early diagnosis and appropriate management can prevent progression to acute mesenteric ischemia, which carries a high mortality rate.