There is a reason aortic aneurysm is known as “the silent killer.” Most people who have an aneurysm have no symptoms at all. Most only discover they have an aneurysm incidentally during imaging tests for another problem. This poses a real danger because over time, aortic aneurysms can grow. And when they are not treated, they can rupture without warning, resulting in potentially life-threatening internal bleeding.
The good news is that an aortic aneurysm that is diagnosed early can be monitored and, before it becomes dangerous, treated successfully.
“One of the silver linings to this complex cardiovascular condition is that timely, elective intervention can lead to excellent long-term outcomes,” says Prashanth Vallabhajosyula, MD, MS, director of Yale's Aortic Institute, part of Yale New Haven Hospital’s Heart and Vascular Center. “Furthermore, we are able to increasingly provide minimally invasive surgical options to our patients, enabling a faster recovery for them.”
What is the aorta?
The aorta is the biggest blood vessel in the body. Measuring around an inch in diameter, it carries oxygenated blood from the left side of the heart—specifically, the left ventricle—to the rest of the body (except the lungs).
When the left ventricle contracts, it pumps blood through the aortic valve and into the aorta. The blood first enters the ascending aorta, a segment of the aorta that moves up toward the head. The aorta then curves to the left. This curved section is known as the aortic arch. Three arteries branch off from the aortic arch to carry blood to the brain, head, and arms.
After the arch, the aorta then descends through the back of the chest and into the abdomen. This portion of the aorta is called the descending aorta, and it is divided into two sections: the thoracic aorta (the portion that passes through the chest) and the abdominal aorta (the part passing through the abdomen).
Several arteries branch off from the thoracic and abdominal sections of the aorta to carry blood to the esophagus, stomach, liver, intestines, and other organs, and in the abdomen, it divides into two arteries that deliver blood to the legs.
What is an aortic aneurysm?
Healthy arteries—including the aorta—have strong walls, made up of three layers: an inner layer of cells, a middle layer of elastic tissue, and a tough outer layer of connective tissue.
But certain factors—high blood pressure, smoking, and certain inherited disorders, among others—can cause the aorta’s wall to weaken. When this happens, the pressure exerted as blood flows through the aorta can cause the weakened areas of the wall to bulge outward. This abnormal bulging of the aorta is known as an aortic aneurysm.
Aortic aneurysms can occur anywhere along the aorta, but there are two main types:
- Thoracic aortic aneurysms (TAA) form in the part of the aorta that passes through the chest.
- Abdominal aortic aneurysms (AAA) occur in the portion of the aorta that passes through the abdomen. They are more common than TAAs and occur more frequently in males than in females.
Small aneurysms may not cause any noticeable problems. But over time, aneurysms grow, and as they do so, they can rupture. When this happens, the aortic wall bursts open and blood flows out of the aorta and into surrounding tissues.
Aortic aneurysms can also cause problems in other ways. Blood clots can form where the aorta’s walls bulge outward. They can then break away and travel to and get lodged in smaller arteries, where they can reduce or block blood flow to vital organs. Aortic aneurysms can also cause problems when they grow large enough that they press against nearby structures and tissues.
Aortic aneurysms can also increase the risk for an aortic dissection, a condition in which a tear develops in the inner layer of the aorta’s wall. Blood then flows out of the tear, between the inner and middle layers of the wall, causing the layers to separate, or dissect, from one another. This reduces the amount of blood that flows though the aorta to other tissues. It also causes the aorta to bulge outward, increasing the risk of rupture.
What are the risk factors for aortic aneurysm?
Several factors are associated with increased risk for aortic aneurysm, including:
- Cigarette smoking
- Increasing age
- High blood pressure
- Family history of aortic aneurysm and/or dissection
- Certain inherited connective tissue disorders including Marfan syndrome, Ehlers-Danlos syndrome, and Loeys-Dietz syndrome, among other genetic conditions
- Bicuspid aortic valve (BAV)
- High blood cholesterol
- Chronic obstructive pulmonary disease (COPD)
- Coronary artery disease
- Syphilis infection
- Physical injury, such as from an automobile accident
What are the symptoms of aortic aneurysm?
Most aortic aneurysms do not cause any symptoms prior to rupture. In some cases, however, they can cause the following symptoms:
Symptoms of unruptured TAAs may include:
- Chest pain
- Shortness of breath
- Difficulty or painful swallowing
- Coughing up blood
Symptoms of unruptured AAAs may include:
- Abdominal pain
- Feeling pulsations in the abdomen
- Low back pain
- Pain in groin, legs, buttocks, or scrotum
- Blood in urine
When aortic aneurysms rupture, they can cause the following symptoms:
- Severe pain in chest, abdomen, back, hips, or sides
- Low blood pressure
A ruptured aortic aneurysm is a life-threatening medical emergency that requires immediate medical attention.
How are aortic aneurysms diagnosed?
If your doctor suspects an aortic aneurysm, he or she will review your medical history, conduct a physical exam, and order one or more diagnostic tests to make a diagnosis.
Your doctor will begin by asking you about your symptoms and whether you have any risk factors associated with aortic aneurysm. During the physical exam, he or she may feel your abdomen to check for signs of an aneurysm and use a stethoscope to listen to your heart and blood flow.
Diagnosis requires imaging tests that allow the doctor to examine internal tissues. These tests may include an ultrasound, a computed tomography (CT) scan, a magnetic resonance imaging (MRI) scan, and/or an echocardiogram (an ultrasound of the heart).
Screening tests to detect or monitor aortic aneurysms may be available for people who are at increased risk for the condition. This includes people with an inherited condition associated with aortic aneurysm (Loeys-Dietz syndrome, Marfan syndrome, etc.), a bicuspid aortic valve, a genetic mutation linked to the condition, family history of aortic aneurysms, or, for AAA, people over age 65 who have a history of smoking.
How are aortic aneurysms treated?
The treatment of aortic aneurysms varies based on the location, size, and other factors. Treatments may include:
Lifestyle changes. Smokers should quit smoking. Doctors may also advise patients to avoid weightlifting, lifting heavy objects, or strenuous exercise.
Monitoring. For people with small, asymptomatic aortic aneurysms, doctor may opt to monitor the aneurysm at regular intervals using ultrasound or CT scans. If the aneurysm grows large enough or causes symptoms, surgery or endovascular repair may be necessary.
Medications. People with high blood pressure, high blood cholesterol levels, and atherosclerosis may be given drugs to get these conditions under control. Medications may include beta blockers, angiotensin-converting enzyme (ACE) inhibitors, angiotensin-receptor blockers (ARBs), statins, and aspirin. Some of these drugs may also slow the growth of aneurysms.
Surgery. Large aneurysms or those that cause symptoms are typically treated with surgery. Ruptured or dissected aneurysms may require immediate surgical intervention. Surgical procedures for treating aortic aneurysms include:
- Open surgical repair. In this procedure, a surgeon makes an incision in the patient’s abdomen, side, or chest to access to the site of the aortic aneurysm. He or she will then remove the section of the aorta where the aneurysm is located and replace it with a prosthetic graft. The graft is a fabric tube that must be sewn in place.
- Endovascular aneurysm repair (EVAR). In this minimally invasive procedure for AAA, a surgeon will make a small incision in the groin to access the femoral artery. He or she will then insert a catheter (a thin tube) into the artery along with a collapsed stent graft (a fabric tube reinforced with metal, also called an endograft), and guide it to the site of the aneurysm. Once there, the surgeon will insert a stent graft into the aneurysm and open it. Blood can then flow through the stent and, over time, the bulging aorta walls will contract to fit around the stent.
- Thoracic endovascular aneurysm repair (TEVAR). TEVAR is used to treat patients with TAA. It is similar to the EVAR procedure described above.
- Branched or fenestrated EVAR (branched or fenestrated endograft). Several vital arteries branch off from the aorta to supply oxygenated blood to the brain, kidneys, and other organs. Traditionally, aortic aneurysms at or near these sites have been treated with open surgery. Recently, they have also been treated using stent grafts designed to repair the aortic aneurysm, while also connecting to the nearby arteries that branch off the aorta. A branched stent graft contains branches designed to fit the arteries that branch off the aorta. A fenestrated stent graft has holes in it that line up with these arteries.
- Hybrid aortic arch procedure. This procedure may be used to treat aneurysms that form in the aortic arch—the curved portion of the aorta above the heart from which arteries branch off to deliver blood to the arms, neck, and head. It combines open surgery and endovascular aneurysm repair. A surgeon first performs open surgery to reroute the blood flow through the arteries to an area of the aorta that is not affected by the aneurysm. After open surgery, the surgeon then performs a TEVAR procedure to insert a stent graft in the aneurysm.
- Valve-sparing aortic root replacement. This procedure may be used for patients with an aortic root aneurysm but whose aortic valve still functions normally. The aortic root is the very beginning of the aorta that attaches to the heart. It contains the aortic valve, which controls the flow of blood from the heart to the aorta. In this procedure, a surgeon removes the aortic root and replaces it with a prosthetic graft (a fabric tube). The patient’s aortic valve is then implanted within this prosthetic graft, thus preserving, or “sparing” it. In cases in which the patient’s aortic valve does not work properly, the surgeon will replace it with a mechanical or tissue heart valve.
- Ross procedure. The Ross procedure may be used to treat patients who have an aortic root aneurysm, as well as unrepairable disease in the aortic valve. In this procedure, the surgeon replaces the defective aortic valve and aortic root with the patient’s own pulmonary valve and the root of the pulmonary artery. An artificial valve replaces the pulmonary valve
- Ozaki procedure. This procedure is used to treat patients with aortic valve disease but whose aortic valve cannot be repaired.the surgeon removes the diseased aortic valve and constructs a new one using the patient’s own pericardium, which is tissue that surrounds the heart. This procedure avoids the use of any artificial material to replace the patient’s diseased aortic valve. Young patients who choose not to get a mechanical aortic valve replacement or are not interested in artificial aortic valve implant may choose the Ozaki procedure.
How is Yale Medicine unique in its care of aortic aneurysm?
“At Yale, patients with thoracic aortic aneurysms are offered comprehensive care by expert surgeons and specialists,” says Roland Assi, MD, MMS. “Our patients have access to cutting-edge expertise and technological advances tailored to their condition, making surgery extremely safe and effective. Patients are offered genetic testing and have access to lifelong aortic surveillance programs, in addition to screening and counseling—including for family members of affected patients.”
The Yale Center for Advanced Thoracic Aortic Disease at Yale New Haven Hospital’s Aortic Institute, part of the hospital’s Heart and Vascular Center, is one of the largest centers in the world for patients with aortic aneurysm. Our specialists often manage the most complex cases.
Our researchers have impacted the way aneurysms are diagnosed and treated. A key component has been the development of a database of thousands of patients, one of the largest organized databases of its kind in the world. The database allows researchers to see patterns in patient populations. It has also helped to clarify such information as the size of aortic aneurysm that should be treated surgically, and to identify “triggers” of aortic dissection, such as extreme physical exertion or intense emotional experiences.
Yale Medicine is also interested in preventing sudden death from aneurysm among its patients’ family members. We strongly recommend family members of affected patients be screened, and we are equipped to arrange for this at the time of the visit.
Written by Jeremy Ledger. Last medically reviewed by Prashanth Vallabhajosyula, MD, MS, and Roland Assi, MD, MMS, in March 2022.
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