Mesenteric Arteries and Median Arcuate Ligament Syndrome

In your abdomen there is a large artery called the aorta. This artery transports the blood from your heart out to your organs and muscles in your abdomen and lower limbs. Just below your ribs there are several branches from the aorta:

• Coeliac trunk
  This is the first branch from the abdominal aorta and it divides into multiple branches to take blood to your stomach, liver and spleen.
  
• Superior mesenteric artery
  This is the second branch from the abdominal aorta and it branches into smaller arteries to take blood to your intestines.

These are the blood vessels which take oxygenated blood from your heart to your digestive system. Unfortunately, sometimes people can develop narrowing in these arteries and this is called atherosclerosis. The atherosclerosis is made up of fatty material which can become calcified and hard. If you develop atherosclerosis in your mesenteric arteries it is possible this can cause a lack of blood to your digestive system. This is known as ischemia, and symptoms may include weight loss and pain after eating.

Median arcuate ligament syndrome occurs when the ligament in the abdomen is located in a position that obstructs the coeliac trunk. As a result, the artery becomes compressed and kinked and may restrict blood flow to parts of your digestive system.

It's important to know that although the sonographer may see some compression of the coeliac trunk, this may not actually be the cause of your symptoms. Some people will have significant compression of their coeliac trunk but be completely asymptomatic. This is why it is important that you see your doctor to discuss all of your clinical symptoms in combination with all the imaging.

The sonographer will use the ultrasound machine to look at the arteries that branch from the aorta in your abdomen. For this scan it is best not to eat or drink (except water) for about four hours before you arrive for your ultrasound as this limits the amount of bowel gas that can interfere with the imaging. If you require food for medication then that is fine to eat.

During the scan you will lie down on the bed. The sonographer will use a transducer and gel to take images of the arteries in your abdomen. Sometimes they will have to press firmly in order to get good views of the artery.

If the sonographer needs to check for median arcuate ligament syndrome (MALS) then they will ask you do some breathing exercises during the scan, taking a deep breath in and also breathing all the way out.

The scan usually takes about 15-30 minutes, after this the sonographer will complete their diagram and report for the referring doctor.