What You Need to Know About Thoracic Aortic Aneurysms
Experts describe how this dangerous aneurysm is best managed.
The aorta is the largest blood vessel in the body and arguably the most important: It carries oxygenated blood away from the heart to all parts of the body.
The section that runs from the heart through the chest is called the thoracic aorta.
When a section of aorta wall weakens, it may bulge as blood surges through it. A bulge, or aneurysm, increases the risk the aorta will burst (rupture) or tear apart (dissect). Both scenarios are medical emergencies that many patients do not survive. That's why preventing a rupture or dissection is so important.
"As soon as a thoracic aortic aneurysm is discovered, the patient should see a cardiologist with expertise in aortic disease. This provides the best chance of appropriate and timely decisions about managing the aneurysm to prevent a catastrophe," says Eric Roselli, MD, director of the Aorta Center at Cleveland Clinic.
Until an aneurysm reaches a certain size, there are many things that can be done to lessen stress on the artery wall. Maintaining tight blood pressure control is critical. New guidelines recommend achieving a target blood pressure less than 130/80 millimeters of mercury (mmHg), which Cleveland Clinic believes is a critical goal for patients with thoracic aneurysm. "This usually requires a medication such as beta blockers. Even a low dose may be helpful," says Dr.Roselli.
Taking It Easy
Most patients with thoracic aortic aneurysm may safely participate in moderately intense aerobic activities, such as walking, jogging or cycling.
Lifting weights or other heavy items should be discouraged, since this may cause a significant short-term increase in blood pressure. "We do not have strong evidence to support specific recommendations about exercise limitations, but in theory, lifting more than half your body weight could increase your blood pressure enough to cause a weak aorta wall to rupture or dissect," Dr. Roselli explains.
When patients are involved in competitive sports, activity restrictions should be tailored to the risk of dissection or rupture. "We may recommend exercise stress testing to assess a patient's heart rate and blood pressure response to exercise," says Dr. Roselli. "We are developing research protocols to learn more about the interaction between these variables so activity recommendations can be tailored to the individual."
When Surgery Is Recommended
The growth of a thoracic aortic aneurysm is carefully monitored, since it is unlikely to cause symptoms until the moment it ruptures or dissects.
Surgery is generally recommended when an aneurysm reaches 5.0 to 5.5centimeters (cm, or about 2inches) in diameter or grows more than 0.5cm per year.
Surgery may be advised earlier in patients with a family history of aortic disease, a bicuspid aortic valve or a known connective tissue disorder, due to increased risk of rupture at a smaller diameter.
In older, sicker patients, the risks of surgery may be greater than the risk that a smaller aneurysm will dissect or rupture.
"We find it is psychologically beneficial for patients to meet with a surgeon relatively early in the course of treatment to learn what surgery involves, its risks and benefits, and to gain some reassurance that we can manage most of these problems very safely," says Dr. Roselli.
Family History Matters
If the patient has a family history of aortic dissection, surgery may be recommended when the aneurysm reaches the diameter of the family member's aorta when the dissection occurred. In some cases, the threshold to operate may be particularly low.
"At our center, we routinely recommend patients with thoracic aortic aneurysm visit a clinical geneticist and have all first-degree relatives screened if there is a suggestion of a family history," says Dr. Roselli.