Melanie Cole (Host): An arterial aneurysm is defined as a focal dilation of a blood vessel with respect to the original artery. The risk of abdominal aortic aneurysm increases dramatically in the presence of certain factors. My guest today is Dr. Adam Beck. He’s the Director in the Division of Vascular Surgery and Endovascular Therapy at UAB Medicine. Welcome to the show, Dr. Beck. Tell us some of those factors that might increase the risk of abdominal aortic aneurysm.

Dr. Adam Beck (Guest): Hi, good morning. The biggest risk for aortic aneurysm are smoking, high blood pressure, high cholesterol. There are some genetic links between patients and aortic aneurysms, so if you have a first-degree relative that has an aneurysm, you would have a higher likelihood of having an aneurysm. Male gender, advanced age are also risk factors for Triple-A.

Melanie: Would they be palpable upon routine physical examination?

Dr. Beck: Well, it depends on the location of an aneurysm and, of course, the size of the patient as you increase in obesity, the likelihood of being able to palpate the aneurysm decreases.

Melanie: Are they usually asymptomatic until they expand or rupture? Tell us about some of the signs and symptoms.

Dr. Beck: Well, the vast majority of aneurysms are asymptomatic, unfortunately, and the majority of aneurysms that we see are found incidentally on imaging that’s performed for some other problem, usually chronic low back pain, or people that present with kidney stones, and that sort of thing. The signs and symptoms -- typically there aren’t any until the aneurysm ruptures, so we do encourage patients that have a large number of risk factors to be screened. There is a “Welcome to Medicare Screen” that’s done at age 65 for men who have smoked over 100 cigarettes in their life, and for people with first-degree relatives.

Melanie: So in the likelihood that an aneurysm will rupture, what is that influenced by? What are some of those factors?

Dr. Beck: Well, it’s mostly physics, so the larger the diameter of the aneurysm, there’s an increasing tension in the wall, the wall gets thinner, and the risk of rupture goes up. For a man, the risk of rupture increases right around 5.5cm and for a woman, right around 5cm. That’s about the time that we start to think about fixing them depending on a number of other factors, but the risk of rupture for a 5cm aneurysm in a woman, and a 5.5cm aneurysm in a man would be about 5% per year.

Melanie: So as an important determinant of the risk of rupture, tell us about expansion rate.

Dr. Beck: Well, there’s a little bit less known about expansion rate, so we do take that into account. Most aneurysms that we see in clinic that are 5.5cm in a man, we would proceed with fixing it as long as the patient’s risk factors for repair were not prohibitively high. We do take that into account, so if we were following an aneurysm, let’s say, that presented at 4.5cm and they increase by more than half a centimeter over a six-month period of time, that would be a more rapid rate of growth than we would expect and we might, in that situation, fix an aneurysm a little earlier because we do feel that there is a higher rupture risk.

Melanie: Can they also present with complications due to thrombosis, or embolization? Speak about those complications.

Dr. Beck: They can. It’s actually pretty rare. The aneurysms do tend to collect something called thrombus on the inner lining of the aneurysm, and that’s partially due to the flow dynamics through an aneurysm. Occasionally, some of that thrombus can dislodge and embolize down the leg and so some patients will present with what we call Blue Toe Syndrome, which is literally just when they have a blue toe from an atheroembolism to the foot.

Melanie: And what about management of an unruptured aneurysm, what do you do?

Dr. Beck: Well, in 2017, we have a lot in our armamentarium, so we can do minimally-invasive or endovascular repair and open repair. Endovascular repair is primarily determined by the patient’s anatomy. When we fix an aneurysm with an endovascular approach, we’re essentially just relining the inside of the artery, and so we have to be able to meet two engineering requirements, which is that we need seal and fixation of the device inside the aorta. We need to seal so there’s no flow into the aneurysm so that it can’t rupture. Then, of course, when we put the device in place, we don’t want it to move over time, and so the patient’s anatomy has to be amenable to an endovascular repair. That said, we still do open aneurysm repairs in properly selected patients. They will do well from that. An open aneurysm repair, there’s really no magic to it. We have to get to the diseased blood vessels, stop the blood flow through the diseased blood vessel, and replace the diseased portion of the artery. Depending on the patient’s risk factors, we still do that, and I would say we probably do open aneurysm repairs across the country in about 10-20% of patients depending on their anatomy.

Melanie: Dr. Beck, what would you tell other physicians about how to speak to a patient if they do have an aneurysm? It can be quite scary for a patient to hear this diagnosis.

Dr. Beck: Well, I think you have to put it into the context of what the risk of doing nothing is, so if we were just to follow the aneurysm over time and try to mitigate any risk factors that they might have, what would be the risk of rupture over time? That’s, as we’ve pointed out earlier, all based on the diameter of an aneurysm. You have to put it into the context of the patient’s other medical conditions and what kind of quality of life they have and what kind of longevity of life -- or at least what we anticipate their longevity of good life is. The last thing is what’s the risk of doing something? And that really is within the prevue of a vascular specialist to talk to the patient about the risk of the actual operation that they need to fix it. What I always tell my patients is that everything I do always has to pass the mom or dad test – what would I do if this patient were my mom or dad in a similar situation? And you have to put those three things together. I think if you put it into that context most of the time, patients will feel at ease and understand that you’re trying to do what’s best for them.

Melanie: And a ruptured aneurysm is one of the most dramatic emergencies in medicine. What do you do as management if you find out it has? And what are some of the symptoms of the rupture?

Dr. Beck: The first symptom is usually pain, and that’s usually back, or flank pain that can radiate to the groin. And then, of course, if the patient presents with hypotension and abdominal or back pain, that has to be a leading part of your differential diagnosis so that they get managed quickly. We do actually do minimally-invasive repair of ruptured aneurysms when we can. When patients present to the emergency room we like for them to go – as soon as they’re medically stabilized if they can be – go straight to a CT scan so that we can get an idea of their anatomy. As I pointed out earlier, the choice of an endovascular versus an open repair really depends on the patient’s anatomy, so we need to know that. Then they can usually go directly from the CT scanner up to the operating room if they have a ruptured aneurysm. Most modern hospitals now have what we call a Hybrid Operating Room, where we can do both a minimally-invasive or an open aneurysm repair, should one or the other be necessary.

Melanie: What about the decision to screen for Triple-A? What goes into that decision?

Dr. Beck: Well, we want to increase our pretest probability that we’re actually going to find patients that have aneurysms. As I pointed out earlier, it really is based on your risk factors for an aneurysm so if you have first-degree relatives, or if you’re advanced age, over 65, if you’ve ever been a smoker, or you're currently a smoker, those patients would typically be screened for an aneurysm with an abdominal ultrasound. Now, some aneurysms are not fully within the abdomen, and an abdominal ultrasound can’t necessarily see them. There are no current recommendations for screening for thoracic aneurysms, so those that are within the chest, but if you have a patient that has a strong family history for thoracic, or a thoracoabdominal aneurysm, then it would probably be reasonable to do at least a chest X-ray, if not a CT scan.

Melanie: And wrap it up for us, Dr. Beck. What would you like other physicians to know about asymptomatic Triple-A’s? What would you like to tell them about managing this clinical presentation?

Dr. Beck: Well, I would say that we have a lot of new tools in our tool box for fixing aneurysms these days, with a minimally-invasive approach. I think a lot of times the physicians that see patients, they think of the 1980’s where the only way we fixed aneurysms was with a big, open repair and they should just consider the fact that we’ve had a lot of advances in endovascular surgery. Often times even if they think the patient is prohibitively high-risk, it’s worth a referral to a vascular specialist just to talk to the patient in the context of their anatomy and rupture risk.

Melanie: And how can a community physician refer a patient to UAB medicine?

Dr. Beck: Well, if they have an urgent, or emergent referral, they can call the UAB MIST line, the 1-800-UAB-MIST line. If they have an elective referral, they just need to give us a call at our office, and we’ll get the patient scheduled within a couple of weeks usually.

Melanie: And tell us about your team. Why is UAB so great to work with?

Dr. Beck: We have a really great multidisciplinary team here. First of all, we have five modern vascular surgeons in our division, and then we have a wonderful operating system within the clinic and within the operating room. We have very modern, state-of-the-art, hybrid operating rooms, where we can do just about anything you could do to a human aorta. The hospital is very supportive of new advances in medicine so there’s really not, as I’ve said, nothing we can’t do here.

Melanie: Thank you, so much, Dr. Beck, for being with us today. You’re listening to UAB Med Cast, and for more information on resources available at UAB Medicine, you can go to UABMedicine.org/Physician, that’s UABMedicine.org/Physician. This is Melanie Cole, thanks so much for listening.