The “Silent-Killer” — Know Your Risks for an Abdominal Aortic Aneurysm

Most people with an abdominal aortic aneurysm don’t show any symptoms — they don’t know that the largest blood vessel in their body is slowly and silently dilating, creating a blood-filled bulge. If left undiagnosed and untreated, the bulge, or aneurysm, could rupture, and the bleeding could be deadly.

“The human body holds about six liters of blood,” said Peter Rossi, MD, chief of vascular and endovascular surgery for the

Froedtert & the Medical College of Wisconsin health network. “The normal rate of blood flow through the body is about six liters per minute. So, theoretically, it is possible for a person to bleed out his or her entire blood volume in one minute due to a ruptured aorta.”

Eighty-five percent of people with a ruptured abdominal aortic aneurysm die before they reach the hospital or have surgery.

Time-sensitive, critical cases

Abdominal aortic aneurysms (AAA) are the 15th leading cause of death in the United States, and each year, 200,000 people are diagnosed with one. The aorta begins at the heart and runs through the center of the chest and the abdomen. In both the chest and the abdomen, the aorta can progressively weaken and enlarge, which creates the aneurysm. Depending on the size of the aneurysm and the rate at which it is growing, treatment ranges from watchful waiting to emergency surgery.

Severe and constant pain in the abdomen or back and a pulsing sensation in the abdomen could be signs the AAA has ruptured. It is important to call 911 immediately. Not all hospitals have the ability to take on these types of cases; many will transfer the person to a center that provides the highest level of surgical care.

“AAAs require complex, multidisciplinary care,” Dr. Rossi said. “Hospitals, locally and regionally, will either transfer or refer AAA patients to Froedtert & MCW Froedtert Hospital because, as an academic medical center, we have the expertise and the resources to handle any case, 24 hours a day, seven days a week, 365 days a year.”

The academic medical center advantage

Ruptured AAAs are life-threatening, but research has shown that outcomes are better when patients are treated at metropolitan teaching hospitals. Froedtert & MCW Froedtert Hospital has protocols in place that streamline care, specifically designed for treating vascular emergencies. A person with a ruptured aneurysm is typically transferred from the helipad directly to the operating room, bypassing the emergency room. The vascular surgery and interventional radiology teams work on these cases together — each specialty brings its specific expertise.

“The close relationship between these two teams is special to our institution,” Dr. Rossi said. “We want to put a lot of eyes on a complex problem to give the best result.”

Abdominal aortic aneurysm repair techniques

Both ruptured and elective aneurysm repairs can be done with endovascular stent grafting — a minimally invasive, catheter-based procedure — instead of an open procedure, which involves an incision from the chest to the abdomen. The location, shape and size of the aneurysm are all factors that help determine how the AAA should be repaired. Endovascular repair is the preferred treatment for AAAs because the risk of complications is lower than with traditional surgery. However, endovascular repair is a technically demanding procedure and requires a skilled surgical team.

“Patients recover faster with endovascular repairs,” Dr. Rossi said. “The standard of care at most academic medical centers is to perform endovascular repairs whenever possible.”

A study of more than 11,000 patients, published in JAMA Surgery, found that outcomes for both open repair and endovascular repair depend greatly on the hospital’s volume of cases. High-volume hospitals that see many AAA patients had better outcomes, and “adequate access to multidisciplinary care” was an important factor for success.

Risk factors

Several factors can increase the risk of developing an abdominal aortic aneurysm:

• High cholesterol, which can lead to atherosclerosis (hardened arteries due to plaque build up)
• Diabetes
• Hypertension (high blood pressure)
• Age: People over the age of 65 are at a higher risk.
• History of smoking
• Genetic factors (inherited tissue disorders)
• Gender: AAAs are four to six times more common in men than in women.
• Family history: If one of your first-degree relatives has had an AAA, you are 12 times more likely to develop one.

Screening

Screening can determine if you have an AAA and if you need treatment. Screening for AAA involves performing an ultrasound of the abdomen to detect the presence of an AAA. AAA screenings are recommended for patients over the age of 65 who have a history of smoking, a family history of AAA or have other risk factors. Talk to your primary care doctor if you have questions about whether you should be screened for AAA.

Alternatively, if you have a family history of AAA or are a man age 65-75 and have smoked 100 or more cigarettes in your lifetime, Medicare will cover a one-time AAA ultrasound with a referral from your provider.