Median Arcuate Ligament Syndrome (MALS)

Diagnosis

To diagnose median arcuate ligament syndrome, also called MALS, a healthcare professional performs a physical exam and asks detailed questions about your symptoms. While listening to your abdomen with a stethoscope, the healthcare professional may hear a whooshing sound known as a bruit. This sound can occur when a blood vessel is narrowed or compressed.

Because many conditions can cause chronic abdominal pain, several tests are usually needed to confirm the diagnosis and rule out other possible causes.

Tests

A combination of laboratory tests and imaging studies may be used to diagnose median arcuate ligament syndrome:

• Blood tests are done to look for conditions affecting the liver, pancreas, kidneys and other organs. A complete blood count shows levels of red and white blood cells. An elevated white blood cell count may suggest infection.

• Abdominal ultrasound uses sound waves to evaluate blood flow through abdominal blood vessels. This test can show compression of the celiac artery, especially during deep breathing in and out.

• Upper endoscopy, also called esophagogastroduodenoscopy or EGD, allows a doctor to examine the esophagus, stomach and upper small intestine using a flexible tube with a camera. Tissue samples may be taken during the procedure for further testing.

• Gastric emptying studies measure how quickly food leaves the stomach. Compression of the celiac artery can slow stomach emptying, although delayed emptying may also be caused by other medical conditions.

• Magnetic resonance imaging uses magnets and radio waves to create detailed images of internal structures. When contrast dye is given through a vein to evaluate blood flow in the arteries, the test is called magnetic resonance angiography or MRA.

• Abdominal computerized tomography creates detailed cross-sectional images using X-rays. When contrast dye is used to better visualize blood vessels, the test is called a computerized tomography angiogram. This imaging can show narrowing or blockage of the celiac artery.

• Celiac plexus block involves injecting a numbing medication around the nerves near the celiac artery. Relief of symptoms after this injection may help predict whether surgery for MALS will be effective.

Treatment

Surgery is currently the only treatment option for median arcuate ligament syndrome. In most people, surgery helps improve or reduce symptoms.

The most common surgical approach is median arcuate ligament release, also known as decompression surgery. This procedure removes pressure from the celiac artery and surrounding nerves. It may be performed as an open surgery through a single incision in the abdomen or as a minimally invasive laparoscopic procedure using small incisions and a camera.

During decompression surgery, the surgeon cuts the fibers of the median arcuate ligament to relieve compression. Nerves around the celiac artery and its branches are often removed. In some cases, bundles of nerves on each side of the artery are also removed.

Some people with MALS may need additional surgery to repair or replace a narrowed or blocked celiac artery to restore normal blood flow.

After MALS release surgery, the hospital stay is usually two to three days. Follow-up imaging, such as an ultrasound or CT scan, may be done about one month after surgery to confirm improved blood flow. Nutritional support may be recommended, especially for people who have had difficulty eating or have experienced significant weight loss.