What Is MALS (Median Arcuate Ligament Syndrome)?

National Leadership in MALS Care

University Hospitals Harrington Heart & Vascular Institute is recognized across the country as leader in advanced minimally invasive and surgical techniques, achieving remarkable patient outcomes. In the area of MALS care, for more than 20 years, vascular surgeon Dr. W. Michael Park has played a key role nationally in improving the diagnosis and treatment of MALS, as well as becoming a devoted MALS patient advocate.

One of just six physicians on the National MALS Foundation Clinical Advisory Board, Dr. Park is working to establish and optimize a Vascular Compression Center within UH Harrington Heart & Vascular Institute. This center operates as a multidisciplinary collaboration between vascular medicine and vascular surgery, gastroenterology, general surgery, psychiatry, social work and pain management.

Signs & Symptoms of Median Arcuate Ligament Syndrome (MALS)?

MALS reduces blood flow to the stomach, liver and other organs, which can result in pain in the upper part of the belly. The symptoms of MALS are often similar to appendicitis, stomachache, irritable bowel syndrome (IBS) and other stomach problems.

Symptoms of MALS include:

• Stomach pain after eating, exercising or changing body position
• Chronic pain in the upper middle stomach area, which may go away when leaning forward
• Bloating
• Nausea and vomiting
• Diarrhea
• Delayed gastric emptying (delay of food moving from the stomach into the small intestine)
• Fear of eating caused by pain, which can lead to significant weight loss (usually greater than 20 pounds)

How Common is MALS?

MALS is a rare condition, with a couple of thousand cases treated annually in the U.S. The condition most often occurs in thin, younger women.

Diagnosis of Median Arcuate Ligament Syndrome (MALS)

Because the symptoms of MALS are similar to other stomach conditions, diagnosis can be a long process, with some patients waiting years for a positive diagnosis.

If your doctor suspects you have MALS, they will perform a physical examination and review your symptoms and medical history. When listening to your upper abdominal area with a stethoscope, your physician may hear a sound called a bruit if you have MALS; a bruit can be present when a blood vessel is narrowed or blocked.

Your doctor may also order blood work and certain imaging tests to help rule out more common causes of symptoms associated with MALS. These include:

• Gastroesophageal reflux disease (GERD)
• Gastritis
• Gastroparesis
• Problems with your pancreas, liver, gallbladder, spleen or intestines
• Atherosclerosis (the buildup and hardening of plaque inside the arteries)

If other conditions are ruled out and MALS is still suspected, your healthcare provider typically will order an ultrasound as the next step. Using high-frequency sound waves, this noninvasive test shows how blood is flowing through your blood vessels. An abdominal ultrasound can show compression of the celiac artery, especially when the patient takes in and releases deep breaths.

Following an ultrasound, a CT scan is usually done to map the anatomy and help with surgical planning. A CT scan is a type of X-ray imaging test that takes cross-sectional images of specific parts of the body. If the celiac artery is narrowed or blocked, an abdominal CT scan can show it. A variant of a CT scan called a CT angiogram, in which dye is injected into a blood vessel to enhance the imaging, may also be used.

The last diagnostic step is usually a celiac plexus nerve block, a procedure performed under fluoroscopy guidance. A celiac plexus nerve block temporarily numbs the nerves under compression in people with MALS. If the procedure brings symptom relief, you may benefit from surgery on the affected ligament and nerves. For some people, a celiac plexus block can relieve MALS-related pain for weeks, months or even years.

Other tests that may be used to diagnose MALS include:

• Magnetic resonance imaging (MRI)/magnetic resonance angiogram (MRA): An MRI test uses radio waves and powerful magnets to produce detailed images of the body. And MRA is a type of MRI where dye is injected into a blood vessel, so the movement of blood through the arteries and veins can be viewed more clearly.
• Upper endoscopy: Also called an esophagogastroduodenoscopy (EGD), this procedure is used to visually examine the upper digestive system. During the procedure, the provider gently guides a long, flexible tube with a camera on its end (endoscope) down your throat following application of a numbing medication. If needed, the provider can also take a tissue sample (biopsy) during the procedure.
• Gastric emptying studies: Compression of the celiac artery can cause slow or delayed gastric emptying. A gastric emptying study can help your doctor determine how fast your stomach empties its contents.

Treatment of Median Arcuate Ligament Syndrome (MALS)

Presently, the only treatment option for MALS is surgery. The most common such procedure is called a median arcuate ligament release, or median arcuate ligament decompression, which is done to reduce painful compression of the median arcuate ligament on the celiac artery. This surgery is increasingly performed as a minimally invasive (laparoscopic or robotic) procedure but is also done as traditional “open” surgery.

In the laparoscopic technique, a vascular surgeon makes five to six small (about 1/2-inch) incisions and inserts instruments through them to separate the median arcuate ligament and divide the nerves of the celiac plexus (neurolysis). The operation stops the ligament from putting pressure on the celiac artery, restores normal blood flow and relieves pressure on the surrounding nerves.

Most patients who get laparoscopic surgery for MALS stay one night in the hospital and are able to resume a normal diet the following morning. Patients receive medication to relieve any pain or discomfort caused by the incisions.

Most people who get this procedure report that their MALS symptoms, such as pain with eating and chronic pain in the upper middle stomach area, significantly improve after their surgery. Patients generally are able to return to their normal activities within two weeks.

Some people with MALS must get traditional surgery instead. In the open technique, a vascular surgeon makes a large incision down the middle of the abdomen. People who have the open MALS release procedure may need to stay in the hospital for three to five days to recover. These patients can usually return to their normal activities within four to six weeks.

Follow-Up Care

Most people who have surgery for MALS will have a duplex ultrasound a month after their procedure to check to see that there is no further compression of the median arcuate ligament.

Some patients continue to have a narrowing of the celiac artery following surgery because of the buildup of scar tissue. This typically does not cause symptoms can be treated with medications or other nonsurgical methods or, more rarely, another celiac plexus block. In addition, sometimes stenting of the of the celiac axis or other endovascular procedures may be needed.

A small percentage of people who experience repeated episodes of MALS may be candidates for surgical release of scar tissue, typically done as an open operation.