In order to diagnose MALS, patients often undergo a multidisciplinary evaluation with several specialties including gastroenterology, vascular surgery, general surgery, cardiology, anesthesia pain management, interventional radiology, and psychological assessment. The evaluation includes several gastroenterology tests including upper endoscopy and colonoscopy, motility studies, gastric emptying tests, and serology studies. Not all patients require all the above-mentioned tests, but an expert opinion of a gastroenterologist is critical to guide the diagnostic work-up and to establish that MALS is the most likely cause of the pain. A surgical consultation with an expert on MALS treatment is needed once the diagnosis is contemplated. Among patients who are on narcotic pain medication, anesthesia pain clinic consultation and a therapeutic plan to decrease or discontinue the use of narcotics is important prior to proceeding with invasive treatment.

The compression of the celiac artery is a key component of the diagnosis of MALS. This can be determined using noninvasive vascular imaging such as duplex arterial ultrasound, computed tomography angiography (CTA), or magnetic resonance angiography (MRA). The use of invasive diagnostic angiography is discouraged and is not necessary to diagnose MALS. Regardless of the imaging method, the study should be performed with respiratory maneuvers to demonstrate the active compression of the artery, which is usually worse on deep expiration. Our preference is to start with a duplex arterial ultrasound and then to obtain a CTA with respiratory maneuvers on inspiration and expiration .

A frequent test is the ‘celiac ganglion block’, which involves local injection of anesthetic and/or steroids in the location of the celiac ganglion and adjacent nerves. The test may be used as a surrogate or “therapeutic trial” to anticipate the effects of surgical treatment of MALS, which involves release or removal of the arcuate ligament muscle and fibers as well as the removal of the adjacent ganglion tissue (ganglionectomy). The surgical treatment can be done using open surgical or laparoscopic approaches. The rationale for performing celiac ganglion blockage is to try to anticipate if numbing of the sympathetic ganglion or nerves would yield symptomatic relief. It remains controversial if the test is absolutely necessary or not, but we favor obtaining a celiac ganglion block to anticipate if there is a correlation with symptoms. In addition, some patients may benefit from longer-lasting effect by local injection of steroids in the celiac ganglion.

Diagnostic tests:

Imaging of the celiac artery compression

  • Duplex or doppler mesenteric ultrasound with breathing protocol with inspiration and expiration
  • Computed tomography angiography (CTA) with breathing protocol with inspiration and expiration
  • Magnetic resonance angiography (MRA)
  • Catheter abdominal angiography with contrast dye

Evaluation of other gastrointestinal disorders     

  • CT scan with and without contrast dye of the chest, abdomen, and pelvis
  • Gastric emptying transit motility study with small bowel follow through
  • HIDA (hepatobiliary iminodiacetic acid) scan of gallbladder
  • Endoscopy (EGD) and colonoscopy with biopsies
  • 24-hour pH impedance probe
  • Esophageal manometry
  • Gastric tonometry
  • Blood work panels
  • Chest X-ray
  • Electrocardiogram (EKG)
  • Stool tests