The circulatory system is an important part of a person’s overall health, but it’s often overlooked until they begin experiencing symptoms of vascular disease. A key component of a person’s circulatory, or vascular, system is the abdominal aorta, the main blood vessel that supplies blood to the abdomen, pelvis and legs. Most people don’t even know it’s there, but in some patients it can expand and create what’s called an aneurysm.
An abdominal aortic aneurysm (AAA) can be deadly if it ruptures, so it’s important to know who is at risk and screen them early before it turns into a life-threatening situation. There are several risk factors, but men are particularly at risk, at a 4:1 rate over women.
Since June is Men’s Health Month, Science Life spoke to Ross Milner, MD, Co-Director of the Center for Aortic Diseases at the University of Chicago Medicine, about what causes an abdominal aortic aneurysm (AAA), guidelines for screening and the latest available treatments.
What exactly is an abdominal aortic aneurysm?
An abdominal aortic aneurysm is a condition in which part of the aorta becomes enlarged. Normally the abdominal aorta is a round circular structure that resembles a pipe, roughly the size of a golf ball. When an aneurysm develops, the aorta expands and its walls become weaker. When the walls weaken the aorta develops a risk for rupturing. We refer to this as an aortic dissection. An aortic aneurysm can be a life threatening condition that requires immediate intervention.
What causes AAA’s? Are people predisposed to them, or are they caused by lifestyle factors like diet?
Research has shown us that people who have high blood pressure, especially poorly controlled high blood pressure, people with high cholesterol, and people who smoke are at the greatest risk for developing an AAA. Family history does play a role with this condition, as a higher incidence of AAA has been observed in families, but it isn’t a given that your children will develop one just because you have one.
Cholesterol, smoking, and high blood pressure are risk factors that we know are found in people with AAA’s, and they also guide us in determining who should be screened.
Men seem to be at particularly high risk for this. Do we know why?
The reason is not well understood, but we do know that there is about a 4:1 rate of men being affected compared to women. Even when the top risk factors of smoking and high blood pressure are present in women, they just aren’t as likely to have an AAA as a man is.
How do you know if someone has an aortic aneurysm? Do they show symptoms?
Ideally we want to identify if someone has an AAA before they have symptoms. By the time a person begins to have symptoms, it means that there’s so much pressure on the aneurysm that they’re going to be at risk for rupturing and being in a life-threatening circumstance. The best time to find them is when they’re asymptomatic.
The simplest way to find an AAA is with a basic physical examination, but that’s not always possible, even with a good physical examination. The best screening test that we have is an ultrasound. It’s non-invasive, it doesn’t hurt, and there’s no radiation associated with it. It’s really a risk free test. Ultrasound allows us see and measure the aorta in great detail and identify an aneurysm if it’s there.
When is the right time to get screened?
People with a family history of AAA should get screened when they’re 50. For people who don’t have a family history, but have other risk factors such as smoking or high blood pressure, we suggest beginning screening at age 65.
I tell my patients who have a family history of this disease, if they get checked at 50 and they’re normal, I usually recommend getting checked again in 10 years. For patients who are 65 and older who have risk factors but don’t have a family history, if they have a normal screening they probably don’t need to be checked again. If it’s a little bit enlarged, then we recommend rechecking once a year or every other year until the AAA grows to a size where we need to check it more frequently.
I really stress with my patients that they should let family members know that it’s important they get screened as well, and they have responded to this advice very well. I’ve had a number of brothers and sisters, as well as children of the appropriate age, come in to get screened, and we’ve been really conscientious about promoting the family history aspect of it for follow up evaluation.
One thing that I want to stress about the screening is that there’s no risk. It’s a completely safe, non-invasive test. Early detection via screening is the key to preventing the potentially life threatening problem that can develop when an AAA is left untreated. It’s a simple test with lifesaving potential.
If you decide you need to intervene, what do you do?
We usually recommend repair when an aneurysm reaches about 5 or 5.5 centimeters. There are two general approaches we can take to repair aneurysms. One is with a standard, open abdominal surgery that has been done for many years. This type of surgery is successful in repairing the aneurysm, however it is a very intensive procedure. The second approach has been developed more recently over the past two decades. It’s an endovascular or stent technique in which the aneurysm is repaired in a much less invasive manner. A lot of aneurysms can now be treated with an endovascular or stent technique and about 90 percent of the patients we see at the University of Chicago are able to have their aneurysm fixed with stents. However, not everybody is a candidate for the stent because the aorta needs to be shaped in a certain way in order to get the stent to work. For these patients we are still able to safely repair their aneurysms with an open procedure.
What’s the prognosis after someone is treated?
For most patients, it’s very good. Overall, we know from the patients we follow after surgery that our long-term results are successful. We tailor the follow-up care to the specific needs of each patient, but in general the, long-term prognosis is very good if you’ve had successful treatment of an AAA.
Is someone likely to get an aneurysm a second time after it’s treated?
There is a low risk of that, but we do follow people to make sure they don’t develop problems. Two issues that do occur on occasion are the development of an aneurysm at a different location, or a problem with the repair. Thankfully there’s a low likelihood of having an issue that requires intervention, but we do follow up with people, usually once a year, sometimes every six months, to make sure that other problems aren’t developing.
Why come to the University of Chicago Medicine to treat an abdominal aortic aneurysm?
There are two things we provide here that I think are outstanding and set us apart when it comes to AAA’s. The first is a free screening program called Dare to CARE. Our Dare to CARE program allows us to screen people who have the risk factors and family history of AAA’s. Then if treatment is necessary, we have a very comprehensive, multispecialty program, called the UChicago Center for Aortic Diseases, which I co-direct with Dr. Takeyoshi Ota. We have a whole multispecialty group that cares for people with aneurysm disease: anesthesia doctors, cardiologists, surgeons, ICU teams and nurses. It’s a huge group that helps coordinate all the care, and we provide a whole array of options for endovascular treatment using stents or standard operations, depending on what the best course of treatment.
What’s on the horizon for future treatments?
The new techniques that we are using are enabling us to treat more of the aorta with an endovascular, or less invasive, approach. Again, one of the nice things about UChicago is that we’re really on the cutting edge, where we’re involved in various clinical trials that allow us to get access to devices sooner than other medical centers. We’re able to treat more complicated aneurysm disease with less invasive techniques. That’s what I see on the horizon for the future of aneurysm care, is to be able to do more and more for complicated aneurysms that involve different parts of the aorta with less invasive techniques.