Enlarged Aorta

Answers to Questions About an Enlarged Aorta Depend on Individual Factors

If you’ve been diagnosed with an enlarged aorta, you likely have many questions about your condition: How big is too big? When should I be worried? What does “watchful waiting” mean? Are there any early warning signs before it bursts?

Most of the answers to these questions depend on a variety of factors, including your age and body size, medical history and the position and size of your aorta, among others.

Is an Enlarged Aorta the Same Thing as an Aortic Aneurysm?

Dr. Michael Shea, a cardiologist at the University of Michigan Frankel Cardiovascular Center, says he hesitates to use the word "aneurysm" when consulting with patients about an enlarged aorta, instead referencing an aortic dilation or a blood vessel issue. “It’s a scary term,” he says, “especially if a patient has a relative who has died from it.”

When an Enlarged Aorta Requires Surgery

Regardless of the terminology, surgery to repair an aortic aneurysm depends on the size of an individual’s aorta, which can vary according to age, gender and the area of the aorta involved. The typical size of an abdominal aorta, for example, is 2.0 to 3.0 centimeters. An enlarged abdominal aorta is typically greater than 3.0 centimeters.

Overall, when an aneurysm grows to 5.5 cm in men and 5 cm in women, these tend to be the sizes where surgery is actively considered. Until then, regular monitoring, also known as “watchful waiting,” is the typical protocol. This may include testing by CT scan or ultrasound imaging. “Every case is different, which causes a lot of angst among patients,” says Dr. Shea.

Conditions Where Rupture of an Enlarged Aorta May Be More Likely

For example, a patient with connective tissue disorders such as Marfan or Loeys-Dietz syndromes typically experiences ruptures at a much lower diameter than a patient without one of these conditions. A patient with a bicuspid valve may also experience rupture at a lower diameter. For example, a person with a 5 cm dilation and a bicuspid aortic valve is more at risk than a person with a 5 cm dilation with no underlying conditions. Overall, patients with these conditions, as well as those with a family history of aneurysm, would be considered for surgical intervention at 4 to 5 cm.

Other Risk Factors

Other risk factors that come into play include:

  • Where the aortic dilation is located: chest (thoracic aortic aneurysm), abdomen (abdominal aortic aneurysm) or a combination of the chest and abdomen (thoracoabdominal aortic aneurysm)
  • Whether the patient is feeling chest pressure
  • Whether the patient’s blood pressure is under control
  • Whether the patient is smoking
  • The patient’s overall lifestyle

Cardiologists also consider whether the dilation is stable or growing. According to Dr. Shea, growth can range from 0.1 to 1 cm a
year, with measurements done on a regular basis, beginning with a baseline evaluation via echocardiogram, CT scan or MRI.

Dr. Shea points out that many patients with a slow-growing aortic dilation never undergo surgery, but are monitored on a regular basis as a precaution to measure any growth.

For more information about aortic disease, visit the Aortic Disease and Frequently Asked Questions about Aortic Disease pages.

Make an Appointment

To make an appointment to discuss your need for an enlarged aorta or other cardiovascular treatment, call the U-M Cardiovascular Center toll-free at 888-287-1082 or email us at CVCCallCtr@med.umich.edu. For more information about what to expect when you call us, visit our Make an Appointment page.