Median arcuate ligament syndrome (MALS)

Date Updated: 12/04/2020

Overview

Median arcuate ligament syndrome (MALS) occurs when the arc-shaped band of tissue in the chest area (median arcuate ligament) presses on, or traps, the artery that supplies blood to the organs in your upper abdomen (celiac artery).

The location of the median arcuate ligament and celiac artery varies slightly from person to person. Typically, the ligament runs across the largest blood vessel in the body (aorta) and sits above the celiac artery without causing problems. But sometimes the ligament or artery may be out of place, causing MALS. The ligament may also put pressure on the network of nerves surrounding the celiac artery (celiac plexus).

MALS may occur in anyone, even children. Other names for MALS are:

Celiac artery compression
Celiac axis syndrome
Dunbar syndrome

Treatment involves surgery to release (decompress) the ligament and restore blood flow through the artery.

Symptoms

Often, compression of the celiac artery doesn't cause any symptoms.

However, those with MALS can have long-term (chronic) stomach pain. Signs and symptoms of MALS include:

Pain in the upper middle stomach area, which may go away when leaning forward
Stomach pain after eating, exercising or shifting body position
Fear of eating food due to pain, leading to significant weight loss — usually greater than 20 pounds (9.1 kilograms)
Bloating
Nausea and vomiting
Diarrhea

Your doctor may hear an abnormal sound called a bruit when listening to your upper stomach area with a stethoscope. The sound occurs when a blood vessel is blocked or narrowed.

When to see a doctor

There are many different causes of stomach pain. If you have stomach pain that continues despite home care, call your doctor. You'll need a complete physical exam and tests to determine the specific cause.

If your stomach pain is severe and activity or movement makes it worse, call your doctor immediately. Seek immediate medical help if your stomach pain occurs with other concerning signs and symptoms, including:

Bloody stools
Fever
Nausea and vomiting that doesn't go away
Severe tenderness when you touch your belly area
Swelling of the belly area
Yellowing of the skin or whites of the eyes (jaundice)

Sometimes upper stomach pain can be confused with chest pain. Get emergency help or call 911 if you have chest or upper stomach pain with or without any of the following symptoms, which might signal a heart attack.

Pressure, fullness or tightness in your chest
Crushing or searing pain that spreads to your jaw, neck, shoulders, and one or both arms
Pain that lasts more than a few minutes or gets worse with activity
Cold sweats
Dizziness or weakness
Nausea or vomiting
Shortness of breath

Causes

Doctors aren't exactly sure what causes median arcuate ligament syndrome. The causes and diagnosis of MALS has been a subject of controversy. The signs and symptoms may be due to a lack of blood flow through the celiac artery, or compression on the nerves (neurological) of the celiac ganglion causing the pain.

Risk factors

Because the cause of MALS is poorly understood, the risk factors for the syndrome are unclear. MALS has been seen in children, even twins, which might mean genetics plays a role.

Some people have developed MALS after pancreatic surgery and blunt injury to the upper stomach area.

Complications

MALS complications include long-term pain, especially after meals, which can lead to a fear of eating and significant weight loss. The pain and related depression or anxiety can greatly impact your quality of life. Because MALS symptoms may be vague and mimic other conditions, it may take some time to get an accurate diagnosis.

Diagnosis

There's no specific test to diagnose MALS. Your doctor will carefully examine you and ask questions about your symptoms and health history. The physical exam is often normal in people with MALS. Bloodwork and imaging tests help your doctor rule out other causes of stomach pain.

Tests used to rule out other conditions and diagnose MALS may include:

Blood tests. Comprehensive blood tests are done to check for problems with your liver, pancreas, kidneys and other parts of the body. A complete blood cell count shows your level of white and red blood cells. A high white blood cell count can mean you have an infection.
Ultrasound of your abdomen. This noninvasive test uses high-frequency sound waves to determine how blood is flowing through your blood vessels. It can show if the celiac artery is compressed, especially when breathing in and out deeply.
Upper endoscopy. This procedure, also called esophagogastroduodenoscopy (EGD), is done to view the esophagus, stomach and upper part of the small intestine (duodenum). During an EGD, the doctor gently guides a long, flexible tube with a camera on the end (endoscope) down your throat after numbing medication is applied. If needed, the doctor can take tissue samples (biopsy) during this procedure.
Gastric emptying studies. Compression of the celiac artery can slow the rate of stomach emptying. Gastric emptying studies are done to determine how fast your stomach empties its contents. Slow or delayed gastric emptying may be from other medical conditions.
Magnetic resonance imaging (MRI). An MRI uses powerful magnets and radio waves to produce detailed images of the body area being studied. Sometimes, dye is injected into a blood vessel to more clearly show how blood moves through your arteries and veins (magnetic resonance angiogram).
Computerized tomography (CT) of the abdomen. CT uses X-rays to create 3D images of the body area examined. An abdominal CT scan can show if the celiac artery is narrowed or blocked. If the diagnosis is still unclear after other imaging tests are done, your doctor may inject a dye into a blood vessel to highlight blood flow in your arteries and veins (CT angiogram).

Treatment

Surgery is the only treatment option for MALS. The most common procedure is called median arcuate ligament release, or median arcuate ligament decompression. It's usually done as an open surgery but sometimes can be done as a minimally invasive (laparoscopic or robotic) procedure.

While you're under general anesthesia, a surgeon divides the median arcuate ligament and network of nerves in the stomach area (celiac plexus). Doing so provides more room for the artery, restores blood flow and relieves pressure on the nerves.

Some people with MALS may need an open surgery to repair or replace a blocked celiac artery and fully restore blood flow (revascularization).

If you have MALS release surgery, you'll usually stay in the hospital for two to three days. You'll need an ultrasound about a month after surgery to confirm that blood flow through the celiac artery is fully restored. Several studies have shown that surgery to release the median arcuate ligament is safe, even in children with MALS. It often results in immediate pain relief and improves the person's quality of life.

Lifestyle and home remedies

Pain and stress often occur in a cycle. Pain can make you feel stressed, and stress can make pain worse. MALS pain may make it difficult to eat, exercise, sleep and do everyday tasks. Relaxation techniques, such as deep breathing and meditation, may ease pain and boost your mental health.

Coping and support

Living with MALS may make you feel sad, anxious or depressed. The challenge of getting an accurate diagnosis — and having so many medical tests — may be overwhelming. Sharing your thoughts and feelings with others who have similar experiences may be helpful. A support group can provide emotional support and help you learn about new coping skills. The National MALS Foundation provides information and connections for people with median arcuate ligament syndrome. Or, ask your doctor, clinic or hospital if they can recommend a support group in your area.

Preparing for an appointment

If you think you have stomach pain that doesn't go away, or think you may have median arcuate ligament syndrome, it's important that you make an appointment with your doctor. If median arcuate ligament syndrome is found early, treatment may be more effective.

A doctor's appointment can be brief, and there is often a lot to discuss. So it's a good idea to be properly prepared for your appointment. Writing down your list of questions or concerns is one of many steps you can take to get ready for your doctor's visit.

What you can do

Be aware of any pre-appointment restrictions. When you make the appointment, be sure to ask if there's anything you need to do in advance, such as not drinking or eating anything for a few hours. You may need to do this if your doctor orders blood or imaging tests.
Write down all your symptoms, including any that may seem unrelated to median arcuate ligament syndrome.
Write down key personal information, including any family history of heart disease, stroke, high blood pressure, blood clots, and any major stresses or recent life changes.
Make a list of all medications, vitamins or supplements that you're taking.
Bring a family member or friend with you, if possible. Sometimes it can be difficult to understand and remember all the information received during an appointment. The person who goes with you may remember something that you missed or forgot.
Write down questions to ask your doctor.

List your questions from most to least important, in case time runs out. For median arcuate ligament syndrome, some basic questions to ask your doctor include:

What is likely causing my symptoms or condition?
What are other possible causes for my symptoms or condition?
What kinds of tests will I need?
What's the most appropriate treatment?
What's an appropriate level of physical activity?
What are the alternatives to the primary approach that you're suggesting?
I have other health conditions. How can I best manage them together?
Are there any restrictions that I need to follow?
Are there any brochures or other printed material that I can take home with me? What websites do you recommend visiting?

Don't hesitate to ask your doctor additional questions during your appointment.

What to expect from your doctor

Your doctor is likely to ask you a number of questions. Being ready to answer them may save time to go over any concerns you want to spend more time on. Your doctor may ask:

When did you first start having symptoms?
Do you always have symptoms or do they come and go?
How severe is your pain?
What, if anything, seems to make your symptoms better?
What, if anything, makes your symptoms worse?