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Super Hero Kids

Pediatric SMAS

Your Inquiries Answered

What is SMAS?

Superior Mesenteric Artery Syndrome (SMAS) is a rare condition that involves the small intestines. This condition occurs when the duodenum is compressed between two arteries. One being the Aorta and the other being a branch of the Aorta called the superior mesenteric artery (SMA). When the space between the aorta and SMA is too tight it can compress the duodenum. This can lead to you having SMAS.

What does the Superior Mesenteric Artery do?

The SMA supplies the midgut, the second part of the duodenum to the splenic flexure of the large intestines. The midgut develops into the distal duodenum, jejunum, ileum, cecum, appendix, ascending colon and proximal ⅔ of transverse colon. Offshoots of the SMA also feed the head of the pancreas. In layman's terms the SMA feeds a lot of structures within your GI.


  • Feeling full quickly when eating

  • Bloating after meals

  • Burping (belching)

  • Nausea and vomiting of partially digested food or bile-like liquid

  • Small bowel obstruction

  • Weight loss

  • Mid-abdominal pain

Diagnostic Tests / Imaging

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How do I receive a diagnosis?

SMAS is considered an exclusion diagnosis. So you will likely go through a lot of tests that come back normal or negative before you get diagnosed with SMAS.

What tests do I need done for a diagnosis?

  • X-rays 

  • Upper GI series

  • Ultrasound

  • Arteriography

  • CT scan

Can I have a GI illness and still have SMAS?

Absolutely, there are SMAS patients who have GI illnesses.

How do you treat SMAS?

There are a variety of treatments available for SMAS patients. Some doctors want to try you gaining weight on your own before doing anything invasive. So they may put you on meal replacement shakes and high calorie diets. Some doctors even recommend proper positioning after eating. Such as lying on your left side, standing or sitting in the knee to chest position. Some patients find that this can alleviate symptoms. But it doesn’t work for everyone.

The next option is Nasogastric decompression (NG Tube). This is a tube that passes through your nose into your stomach. By inserting the tube you can gain access to the stomach and its contents. This makes it so you can drain the contents, decompress the stomach, obtain a specimen or introduce passage into the GI tract. It can also be used as a feeding tube. NG tubes can allow you to treat gastric immobility and bowel obstructions. NG Tubes can also be used to aid in the prevention of vomiting.  

In severe cases you may receive an IV nutritional support and/or have a feeding tube placed to provide enough calories. The hope with this option is that you will be able to start oral liquids then slowly ease into soft meals. Then go back to solid foods if those steps are tolerated. 

Metoclopramide treatment to avoid vomiting may be helpful for some people. Metoclopramide is regularly used to relieve heartburn and speed the healing of sores and ulcers in the esophagus. But it also can be used to relieve symptoms caused by the slow stomach emptying. This medication is in a class of medicine called prokinetic agents. It works by speeding the movement of food through the stomach and intestines. It can also help prevent nausea and vomiting in some people.

Surgery is the final option. Most doctors want to try the other non-invasive steps first in order to avoid putting more strain on the body. SMAS surgery is considered major surgery and shouldn’t be taken lightly. 

Surgical Treatment

There are 3 common surgical options for SMAS, Strong’s Procedure, Gastrojejunostomy and Duodenojejunostomy. 
Strong’s procedure: Where the duodenum is re-positioned to the right of the superior mesenteric artery
Gastrojejunostomy: Where the jejune (the part of the intestines that continues with the duodenum) is joined directly to the stomach
Duodenojejunostomy with or without division or resection of the fourth part of the duodenum.

How does SMAS effect my mental health?

SMAS can be incredibly isolating especially as a pediatric patient. You are supposed to be going out and getting in trouble but you find yourself stuck at home or the hospital. It can feel like your own body is betraying you. It can be hard to admit that you need help or need someone to talk to you. But it's not a bad thing to have a therapist help you through this. It doesn’t make you weak to need help and never feel afraid to ask for it.

Are there illnesses that are common for SMAS patients to have?

Every SMAS is unique but there are some things we share in common, other than this illness. Weirdly enough there are a few illnesses and even surgeries we seem to share. That doesn’t mean that every SMAS patient will have all of these go on with them. Some people may only be dealing with SMAS. 

Some conditions we seem to share:

  • Median Arcuate Ligament Syndrome (MALS) 

  • Nutcracker Syndrome (NCS)

  • Pelvic Congestion Syndrome (PCS)

  • May Thurner Syndrome (MTS)

  • Ehlers Danlos Syndrome (EDS)

  • Mast Cell Activation Syndrome (MCAS)

  • Postural Orthostatic Tachycardia Syndrome (POTS)

  • Gastroparesis (GP)

How do I connect with fellow SMAS patients and caregivers?

There are a few support groups for SMAS patients and caregivers. They can mainly be found on Facebook. Our community is small but it is very compassionate and understanding. It can be a life changing experience to connect with people who understand what you are going through. There may even be people in the exact same spot as you. It can be very helpful to be able to hear both the patient and caregivers experience of SMAS. These groups were created to help us find each other. They have become a safe haven for us to share our victories and our defeats. They aren’t always happy stories but it does help to be able to share and read about our fellow warriors' experiences.

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