The aorta — the largest artery in your body — serves as a sort of highway for transferring high-oxygen blood from the heart to the rest of your body. As soon as it exits the left blood ventricle (aortic bulb), it rises up (ascending aorta), curves around the heart (aortic arch), and then continues to go down (descending aorta) before reaching the abdomen (now called an abdominal aorta), where it finally splits into two iliac arteries supplying the legs and pelvic organs.
The aorta's wall is composed of three layers — the smooth inner layer, the middle layer (mostly elastin fibers), and the outer layer (collagen).
What is aortitis?
Any inflammatory disease that attacks blood vessels is falls under the umbrella of "vasculitis". Vasculitis that strikes the aorta is called "aortitis". This term comprises several groups of diseases, which can be of infectious or non-infectious origin.
Infectious aortitis is caused by microorganisms, and can be classified as:
- Viral (mostly caused by hepatitis viruses or HIV infections).
- Bacterial (mostly caused by Staphylococcus or Salmonella species).
- Mycobacterial (caused by Mycobacterium Tuberculosis), often found in immunocompromised patients, such as HIV-positive people.
- Luetic (caused by syphilis), a sexually transmitted chronic disease, which shows its effects on the aorta several years after the initial infection.
Viruses and bacteria can infect the aortic wall in several ways directly or via blood — the infection can enter your body with an infected needle or during a physical trauma. Most patients with viral or bacterial aortitis are over 50, and men are diagnosed with aortitis more often than women.
Non-infectious aortitis can develop as a part of a different vasculitis, depending on the size of the blood vessel where the disease originated.
That means there are three main non-infectious types of vasculitis, most of them autoimmune diseases.
Large-vessel vasculitis covers:
- Giant-cell arteritis, most common in the USA, with patients mostly being white males older than 50 years.
- Takayasu arteritis, a disease of unknown origin, which can lead to the narrowing and eventual blockage of the aorta (which is why it’s known as a “pulseless disease”), although aneurysms have also been described. It’s more common in Asian females.
- Systemic lupus erythematosus, primarily associated with other aortic issues (blood clots, aneurysms, dissection), leading to vasculitis.
- Ankylosing spondylitis, a rheumatic disease associated with aortic valve problems, potentially leading to heart failures and strokes.
Medium-vessel vasculitis includes:
- Rheumatoid vasculitis, which can affect the aorta, aortic valve, and the heart itself.
- Polyarteritis nodosa
- Kawasaki’s disease
Small-vessel vasculitis is seen in:
- Behçet disease
- Cogans’s Syndrome
- Granulomatosis with polyangiitis
Aortitis can also be induced by ionizing radiation, mostly as a result of radiation therapy, or sarcoidosis. It can further develop without a previously known cause, also known as an idiopathic aortitis, diagnosed mainly in the thoracic part of the aorta in women during aneurysm surgery.
Do I have aortitis?
Because the term "aortitis" encompasses such a large number of different diagnoses, signs and symptoms may vary depending on the part of the aorta affected, as well as the cause behind the infection. That brings us to the conclusion that the symptoms are most often non-specific.
The most common signs and symptoms include:
- Fever
- Headache, vertigo
- Back pain
- Weight loss
- Fatigue
- Night sweating
- High blood pressure
- Claudication (muscle cramps and pain)
- Issues with the aortic valve
- Issues with damaged aortic wall, such as aneurysms, dissections, blood clots, and aortic rupture
Because these signs range from a simple fever to a catastrophic aortic rupture, doctors need to thoroughly investigate the disease so they can reach a correct diagnosis.
How is aortitis diagnosed?
Blood and urine tests are the first step in this complicated process. Besides a complete blood count, it involves liver and kidney function, rheumatologic and inflammation parameters so doctors can try to pinpoint what the kind of arteritis you are dealing with. The benefit of a laboratory test is that it can tell you the nature of the aortitis, so that medications can be prescribed immediately.
Today, modern imaging solutions are routinely used to make a diagnosis of aortitis. By visualizing the blood vessel and comparing the results clinically and with the tests in the laboratory, we can learn a lot about the vessel.
Imaging modalities used in aortitis diagnosis are:
- Ultrasound can visualize the thickened aortic wall, but it’s also useful in the diagnosis of stenosis, blood clot and aneurysm. With the doppler option, blood flow can be viewed and measured. Transesophageal ultrasound (TEE) is also useful when visualizing the heart and the ascending aorta.
- CT scan. Because of its high resolution, you can see both the aortic wall and its lumen, alongside other blood vessels and organs.
- MRI scan. Similar to a CT, maybe even more precise, although still an option unavailable to some (people with metallic implants and impaired kidney function can’t do an MRI scan).
- Angiography. Once the gold standard, CT scans have largely replaced this diagnostic technique today. It can visualize blood flow with great precision. The downsides are that you can’t see the aortic wall. Also, it’s an invasive procedure involving a relatively high dose of radiation.
- PET scan. Positron-emission tomography helps assess inflammatory activity in your organism. Another upside is that you can view a hybrid PET-CT scan, and enjoy the best of both worlds.
How is aortitis treated?
If the cause of the aortitis is infectious, the first step is to get rid of those microorganisms. In case of bacteria, your doctor will prescribe antibiotics, or some other culture-specific drug, depending on the nature of the microorganism.
Prednisone is the medication of choice in large-vessel diseases. As a corticosteroid, it suppresses the immune system, so it is used as an anti-inflammatory drug or as an immunosuppressant medication. Other medications may include methotrexate, azathioprine, and infliximab.
If the aortitis is associated with potential complications such as aneurysms or stenosis, surgery is in order.
Open aortic reconstructive surgery involves replacing the damaged part of the aorta with a synthetic graft.
The aorta can also be revascularized, either through surgery or with the help of a catheter.
Dilatation with the help of a balloon catheter, or making a bypass are also potential options for the surgeon.
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