Overview

Median arcuate ligament syndrome (MALS) occurs when the arc-shaped band of tissue in the chest area (median arcuate ligament) presses on the artery that sends blood to the upper abdomen. The artery is called the celiac artery. MALS can cause stomach pain in some people.

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). It sits above the celiac artery. 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 median arcuate ligament syndrome (MALS) can have long-term (chronic) stomach pain. The symptoms may be due to a lack of blood flow through the celiac artery or compression on nerves in the area.

Symptoms of MALS include:

  • Pain in the upper middle stomach area, which may go away when leaning forward
  • Stomach pain after eating, exercising or changing body position
  • Bloating
  • Diarrhea
  • Fear of eating food due to pain, leading to significant weight loss — usually greater than 20 pounds (9.1 kilograms)
  • 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 health care provider. 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 provider immediately. Seek immediate medical help if your stomach pain occurs with:

  • 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. Sometimes it can be due to a heart attack. Get emergency help or call 911 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

Doctors aren't exactly sure what causes median arcuate ligament syndrome. The causes and diagnosis of MALS are a subject of controversy.

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. 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 and can mimic other conditions. It may take some time to get an accurate diagnosis.

By Mayo Clinic Staff