Median arcuate ligament syndrome (MALS)

Updated: 2024-12-13

Overview

Median arcuate ligament syndrome, also called MALS, happens when the band of tissue in the upper belly area presses on the artery that sends blood to the stomach, spleen and liver. This tissue is called the median arcuate ligament. The artery is called the celiac artery.

The median arcuate ligament creates a pathway between the chest and belly area for the body's main blood vessel, called the aorta. Typically, the ligament goes across the aorta. The celiac artery sits just below the arch.

But sometimes, the ligament or arteries may be out of place. The ligament may put pressure on the celiac artery and the network of surrounding nerves, called the celiac plexus. This pressure can cause the symptoms of MALS. The condition can cause serious stomach pain in some people.

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

• Celiac artery compression syndrome.
• Celiac axis syndrome.
• Dunbar syndrome.

Treatment involves surgery to release pressure from the ligament on the artery and nerves.

Symptoms

Pressure on the celiac artery doesn't always cause symptoms. MALS symptoms are mainly caused by pressure on the nerves.

Symptoms of MALS include:

• Stomach pain after eating or exercising.
• The stomach pain gets better by leaning forward or backward or standing while eating.
• Fear of eating food because of pain.
• Unintended weight loss.
• Bloating.
• Diarrhea.
• Nausea and vomiting.

When to see a doctor

There are many different causes of stomach pain. If your stomach pain continues despite home care, call your healthcare professional. You need a complete physical exam and tests to determine the specific cause.

If your stomach pain is bad and activity or movement makes it worse, call your healthcare professional immediately. Get medical help right away if your stomach pain occurs with:

• Bloody stools.
• Fever.
• Nausea and vomiting that doesn't go away.
• Severe tenderness when you touch your belly.
• Swelling of the belly.
• Yellowing of the skin or whites of the eyes, also called jaundice.

Sometimes upper stomach pain can be confused with chest pain. Sometimes chest pain can be due to a heart attack. Call 911 or emergency medical help if you have chest or upper stomach pain with or without any of the following symptoms:

• 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.
• Shortness of breath.
• Cold sweats.
• Dizziness or weakness.
• Nausea or vomiting.

Causes

The exact cause of median arcuate ligament syndrome, also called MALS, is not known.

Risk factors

Because the cause of MALS is poorly understood, the risk factors are unclear. Median arcuate ligament syndrome is more common in adults than in children. It also is more common among women than among men.

MALS also has been seen in identical twins, so genetics may play a role.

Some people have developed median arcuate ligament syndrome after pancreatic surgery or blunt injury to the upper stomach area.

Complications

A complication of median arcuate ligament syndrome, also called MALS, is long-term pain, especially after meals. The pain can lead to a fear of eating and significant weight loss. The pain and related depression or anxiety can greatly impact quality of life. MALS symptoms may be vague. The symptoms can be similar to those of other conditions. It may take some time to get an accurate diagnosis.

Diagnosis

To diagnose median arcuate ligament syndrome, also called MALS, a healthcare professional examines you and asks questions about your symptoms. The healthcare professional may hear a whooshing sound, called a bruit, when listening to your stomach with a stethoscope. The sound may occur when a blood vessel is narrowed.

Tests

Because many conditions can cause stomach pain, you usually have many tests to find the cause and rule out other possible conditions.

Tests to diagnose median arcuate ligament syndrome may include:

• Blood tests. These tests are done to check for health conditions involving the liver, pancreas, kidneys and other parts of the body. A complete blood cell count shows the level of white and red blood cells. A high white blood cell count can mean there's an infection.
• Ultrasound of the abdomen. This test uses sound waves to see how blood is flowing through the blood vessels. It can show if the celiac artery is compressed, especially when breathing in and out deeply.
• Upper endoscopy. This procedure also is called esophagogastroduodenoscopy, known as an EGD. It's done to see the esophagus, stomach and upper part of the small intestine. During an EGD, a doctor guides a long, flexible tube with a camera on the end down the throat after applying numbing medicine. Also, tissue samples, called biopsies, can be removed for lab tests.
• Gastric emptying studies. Pressure on the celiac artery can slow the rate of stomach emptying. These tests can show how fast the stomach empties its contents. Slow or delayed emptying may be caused by other medical conditions.
• Magnetic resonance imaging (MRI). An MRI uses magnets and radio waves to make detailed images of the body area being studied. Sometimes, dye, called contrast, is given by IV. The dye show how blood moves through the arteries. This is called a magnetic resonance angiogram, also known as an MRA.
• Abdominal computerized tomography (CT). A CT scan uses X-rays to create cross-sectional images of parts of the body. This test can show whether the celiac artery is narrowed or blocked. A dye, called contrast, may be given by IV. The dye helps blood vessels show up more clearly on the test images. When dye is used, the test is called a computerized tomography angiogram.
• Celiac plexus block. Numbing medicine is injected into the nerves that sit on each side of the celiac artery. The numbing medicine lasts for several hours. This treatment mimics what happens during surgery to treat MALS. This test is often used to learn who may do well with MALS surgery.

Treatment

Surgery is the only treatment for median arcuate ligament syndrome, also called MALS. Surgery for MALS can improve or reduce symptoms in most people.

The most common surgical treatment is median arcuate ligament release, also called decompression. It's usually done as an open surgery through a cut in the belly area. Sometimes it is done using a camera and small instruments passed through several smaller openings. This is called laparoscopic surgery.

During decompression surgery, the surgeon cuts away parts of the median arcuate ligament. This reduces pressure on the celiac artery and nerves. The surgeon removes the nerves around the celiac artery and its branches. Bundles of nerves on each side of the celiac artery also may be removed.

Some people with MALS also may need surgery to repair or replace a blocked celiac artery and restore blood flow.

If you have MALS release surgery, you usually stay in the hospital for 2 to 3 days. You may have an ultrasound or a CT scan about a month after surgery to make sure that blood flow is fully restored. You may need to see a nutritionist to help with returning to a healthy diet. This is particularly helpful if you have not been eating or have lost a lot of weight.

Lifestyle and home remedies

Pain and stress often occur in a cycle. Pain can make you feel stressed. 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 reduce pain and improve mental health.

Coping and support

Living with MALS may make you feel sad, anxious or depressed. The challenge of getting an accurate diagnosis 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 new coping skills.

The National MALS Foundation provides information and connections for people with median arcuate ligament syndrome. Also, ask a member of your healthcare team to recommend a support group in your area.

Preparing for an appointment

Make an appointment with your healthcare professional if you have stomach pain that doesn't go away or other symptoms of median arcuate ligament syndrome.

A medical 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 appointment.

What you can do

• Be aware of anything you need to do before your appointment. You may be told not to eat or drink for a few hours before some blood or imaging tests.
• Write down all your symptoms, including any that may not seem related to median arcuate ligament syndrome.
• Write down important personal information, including any family history of heart disease, stroke, high blood pressure or blood clots, and any major stresses or recent life changes.
• Make a list of all medicines, vitamins or supplements that you're taking. Include dosages and reasons for taking each.
• Bring a family member or friend with you, if possible. Sometimes it can be hard to understand and remember all the information you receive during an appointment. The person who goes with you may remember something that you missed or forgot.
• Write down questions to ask your healthcare professional.

List your questions from most to least important in case time runs out. For median arcuate ligament syndrome, some basic questions to ask your health professional 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 best treatment?
• What's the right 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?
• Is there any information that I can take home with me? What websites do you recommend visiting?

Don't hesitate to ask any other questions.

What to expect from your doctor

Your healthcare professional is likely to ask you many questions. Being ready to answer them may save time to go over any concerns you want to spend more time on. Your healthcare team may ask:

• When did the symptoms start?
• Do you always have symptoms or do they come and go?
• How bad is your pain?
• What, if anything, seems to make your symptoms better?
• What, if anything, makes your symptoms worse?
• Do you avoid eating or exercising because of stomach pain?
• Have you lost weight?