Dunbar syndrome is a condition that causes severe abdominal pain and is caused by compression of the visceral artery by the medial arcuate ligament, which connects the diaphragm to the spine. The pressure this creates on a nerve group can cause severe abdominal pain, which is further aggravated during and after eating. Other symptoms that may arise include nausea, vomiting, diarrhea, fatigue, intolerance to physical exertion and ultimately even malnutrition. The diagnosis of Dunbar syndrome is often only made once many other disorders, including the intestines, stomach and gallbladder, have been excluded.

Dunbar syndrome

• Dunbar syndrome in brief
• Symptoms
• Making a diagnosis
• Cause
• Therapy

Dunbar syndrome in brief

Dunbar syndrome is a condition that causes severe and incessant abdominal pain due to compression of the celiac artery by the medial arcuate ligament, which is located at the base of the diaphragm. Dunbar’s syndrome is also known by the following English names:

• Median arcuate ligament syndrome (MALS)
• Celiac trunk compression syndrome
• Celiac axis syndrome

Symptoms

People with Dunbar syndrome usually present with a severe form of abdominal pain that does not go away and often worsens during and shortly after eating. Patients can therefore vomit a lot and eventually eat so little that they become malnourished. The pain occurs in the diaphragm, the part of the upper abdomen just below the ribs, also called the epigastrium. The pain can be on either the left or right side. As a result of the pain and the little food that patients usually consume, many also suffer from a lack of energy and an inability to tolerate physical exertion. People often feel very nauseous for long periods of time. The condition is often accompanied by diarrhea, but there are also patients who exhibit constipation. Lying or sitting in a certain position can make the pain worse. A physical examination by a doctor may reveal increased noise from the blood vessels in the epigastrium.

Making a diagnosis

The diagnosis of Dunbar syndrome is not an easy one. Often people have already been examined for numerous other conditions and the diagnosis is the result of ruling out many other possible causes. The entire digestive tract has often already been x-rayed using, among other things, an endoscopy, colonoscopy and a screening for reflux disease and various gallbladder diseases. If it is suspected that a patient suffers from Dunbar’s syndrome, the best diagnostic test is often a duplex examination, which consists of a combination of an ultrasound of the blood vessels and measuring the flow velocity of the blood in the relevant vessels. An increased flow velocity of the blood in the celiac artery or intestinal artery is then observed. More clarity can possibly be obtained by making an angiography in which the anatomy of the celiac trunk is further examined.

Cause

The abdominal pain characteristic of Dunbar syndrome is caused by compression of the celiac artery by the middle arcuate ligament, which is located at the base of the diaphragm. The visceral artery is an important branch of the aorta, which supplies blood to the stomach, liver and other vital organs. The middle arcuate ligament is a piece of tissue that curves around the aorta and connects the diaphragm to the spine. In people with Dunbar syndrome, the arcuate ligament functions like a hammer and the celiac trunk acts like an anvil between which nerves are squeezed, causing severe pain. This can also occur without causing complaints. Only when it causes complaints is it referred to as Dunbar syndrome.

Therapy

The only way to relieve the symptoms of Dunbar syndrome is to resolve the compression of the celiac trunk. This requires a procedure in which the nerve group where the pain originates is provided with a blockade. This procedure is done under local anesthesia. You lie on your stomach on a table and a thin needle is inserted into your back under the guidance of X-rays. This involves injecting an anesthetic. If the pain returns, the procedure must be repeated. While a nerve block only provides pain relief for a few weeks for one patient, it may continue to have an effect for years for another. To definitively solve the problem, a surgical procedure can be chosen to remove the compression.