Thoracic aortic aneurysm: causes and treatment

The aorta is the main artery carrying oxygen-rich blood from the heart to the rest of the body. The thoracic part runs through the chest. Leeds Teaching Hospitals explains that it is measured at six points along its course, and that an aneurysm is an enlargement to 1.5 times the expected diameter at one or more of them.

The wall of a healthy aorta is strong and elastic. BHF says that in an aneurysm the wall has weakened and lost its elasticity, so it does not return to shape after the blood has passed through. Patient.info says it can involve the ascending aorta, the arch, the descending aorta or the thoracoabdominal aorta.

The danger is a tear between the layers of the wall, called aortic dissection, or a rupture. BHF says dissection can be life-threatening if not treated immediately. Depending on size and growth, many aneurysms never burst or tear.

BHF lists several causes: atherosclerosis, high blood pressure, high cholesterol, genetic conditions, a congenital problem with the aorta or aortic valve, blood vessel inflammation such as giant cell arteritis or Takayasu arteritis, rarely untreated infection such as syphilis, and traumatic injury. It adds that aneurysms in younger people often have a genetic cause.

Patient.info names high blood pressure as the major risk factor for thoracic aortic disease. It also lists increasing age, smoking, high lipids, bicuspid aortic valves, sleep apnoea, chronic kidney disease and cocaine use. It notes weightlifting and stimulants may contribute through large rises in blood pressure.

• High blood pressure and smoking

• Atherosclerosis and high cholesterol

• Marfan, Loeys-Dietz and vascular Ehlers-Danlos syndromes

• A bicuspid aortic valve or other congenital aortic problem

• Inflammation of the aorta, for example from giant cell arteritis

• Family history of aortic aneurysm or dissection

As a thoracic aortic aneurysm grows, BHF says symptoms may include back pain, cough, a weak, scratchy voice, shortness of breath and tenderness or pain in the chest. Leeds Teaching Hospitals adds pain in the jaw, a hoarse voice, and difficulty breathing or swallowing for larger aneurysms. These come from pressure on nearby structures.

A bursting or tearing aneurysm is an emergency. BHF lists sharp, sudden pain in the upper back that spreads downward, pain in the chest, jaw, neck or arms, difficulty breathing, very low blood pressure, trouble swallowing and loss of consciousness. Patient.info says dissection typically brings sudden, very severe, tearing pain at its maximum from the start, unlike the building pain of a heart attack.

BHF says thoracic aortic aneurysms are often found when a test is done for something else. Tests used include chest X-ray, ECG, echocardiogram, cardiac CT scan and cardiac MRI scan. Patient.info says CT with contrast is the most widely used diagnostic tool and that echocardiography shows the aortic valve and root.

BHF notes that aortic conditions can be inherited. If a close relative has had an aortic aneurysm you should speak to your doctor about screening for you and your family. Genetic testing is available for aortic conditions and is recommended through an inherited cardiac clinic. Leeds Teaching Hospitals says relatives may be invited for assessment by a clinical genetics team.

Once an aneurysm is known, scans are repeated at intervals so changes in size can be seen early. BHF says how fast the aneurysm grows, if at all, differs for everyone.

BHF says treatment varies from regular health checks to emergency surgery, depending on cause, size, location and growth rate. Leeds Teaching Hospitals says treatment is tailored and considers size, cause, medical history and your preferences. It offers regular scans, medicines to lower blood pressure which have been shown to slow aortic enlargement, and family screening where genetics may be involved.

BHF lists medicines used to control risk factors, including angiotensin receptor blockers, beta blockers and statins. Patient.info says rigorous blood pressure control, stopping smoking and treating other cardiovascular risks are central.

Surgery is considered when the aneurysm has grown too much, causes symptoms, or in Marfan syndrome. BHF describes replacing the section of aorta with a synthetic graft. Other options are stent-based repair and, for some people with Marfan syndrome, a custom support sleeve around the aortic root. Patient.info says symptomatic aneurysms merit repair regardless of size, and that people with Marfan syndrome or a strong family history are operated on at a smaller size.

BHF says your doctor may advise avoiding heavy lifting and some physical activities that can raise blood pressure and strain the aneurysm. Leeds Teaching Hospitals separates dynamic exercise such as walking, which changes heart rate and blood pressure gradually, from static or explosive exercise such as weight lifting or sprinting, which causes sudden changes. It advises avoiding static exercise and contact sports, and discussing any new activity with your doctor.

Lifestyle measures from the same leaflet include a diet low in saturated fat, not smoking, keeping alcohol to 14 units a week or less and a healthy weight, all of which help lower blood pressure. If you may become pregnant, ask about family planning advice, since a dilated aorta can have a genetic cause.

BHF says that if you have sudden sharp upper back pain that spreads downward, chest, jaw, neck or arm pain, difficulty breathing, trouble swallowing or loss of consciousness, you or someone else should call 999 immediately.

If you have a known aneurysm and notice new chest or back pain, a hoarse voice, a cough that does not go away, or difficulty swallowing, contact your specialist team or GP promptly. Do not assume it is a pulled muscle.

Aneurysms are usually found incidentally and referred to cardiology, cardiothoracic or vascular teams. Some hospitals run dedicated aortopathy clinics, as Leeds does. Surgical planning includes a pre-operation clinic, blood tests and imaging.

Private cardiologists and cardiothoracic surgeons also see people for scans, surveillance and second opinions. Whoever you see, ask which measurement is being tracked, when the next scan is due, and at what size repair would be discussed for you.