Content Reviewers:Jannah Amiel, MS, BSN, RN, Jodi Berndt, PhD, RN, CCRN-K, PCCN-K, CNE, CHSE, Gabrielle Proper, RN, BScN, MN
David Carter is a 65-year-old male client who arrives at the Primary Care Clinic for his annual follow-up appointment.
He was diagnosed with 4.0 cm asymptomatic abdominal aortic aneurysm last year.
Mr. Carter brought in his blood pressure machine from home, and he tells the front desk staff he is feeling anxious about his appointment today.
The artery wall consists of three layers: the tunica intima, tunica media, and the tunica adventitia, which are composed of smooth muscle, elastic fibers and collagen which give the artery strength and elasticity.
So, if the aneurysm forms within the abdominal cavity, it’s called an abdominal aortic aneurysm, or Triple-A.
Likewise, if the aneurysm is found within the thorax, or chest, it’s called a thoracic aortic aneurysm, or T double-A.
Aortic aneurysms come in two basic shapes.
A circular dilation that involves the entire circumference of the aorta is called a fusiform aneurysm.
In contrast, a saccular aneurysm is formed when there’s only a localized outpouching, like a bubble on the side of the aorta.
In cases where there’s only a partial disruption of the artery wall, it’s called a false, or pseudoaneurysm.
In general, an aneurysm that measures between 3 and 4.4 centimeters is considered a small aneurysm; medium aneurysms have a diameter between 4.5 and 5.4 centimeters, and large aneurysms have a diameter 5.5 centimeters or more.
A rapidly expanding aneurysm is defined as one that grows more than 0.5 centimeters in 6 months or more than 1 centimeter per year.
An aortic aneurysm can form due to a number of factors that impair the integrity of the arterial wall.
These factors can be mechanical, inflammatory or congenital.
Hypertension also promotes the formation of atherosclorotic plaque, which results in inflammation and subsequent breakdown of collagen and elastin, two of the most important building blocks of the aortic wall.
Likewise, other risk factors for atherosclerosis such as smoking increase the risk of an aortic aneurysm.
Other risk factors for aortic aneurysms include biological male sex, a family history of aneurysms, and increasing age, where the natural process of aging results in decreased elasticity of the aorta.
A TripIe-A is often asymptomatic and only detected incidentally during a routine examination or screening.
The weakened aortic wall can produce signs like a prominent pulsating mass in the abdomen, usually felt at or above the umbilicus.
Turbulent blood flow through the aneurysm produces a systolic bruit which can be auscultated over the aorta.
Sometimes the turbulence produces microthrombi, which can travel down and occlude the lower extremities, producing cool, painful cyanotic toes, a condition known as blue toe syndrome.
A major complication of aortic aneurysm is dissection and rupture, which happens when the aneurysm enlarges and the layers of the artery wall split, allowing blood to leak in between them.
As the layers begin to tear and eventually rupture, hemorrhage and hypovolemic shock can result.
In cases where the hemorrhage occurs within the retroperitoneal space, the bleeding can be slowed by surrounding structures.
A rupture is a medical emergency and requires immediate stabilization and surgery.
Ultrasound is used to detect the presence, location, and size of the aneurysm, and to monitor it’s growth over time.
Other useful diagnostic studies include computed tomography scan, or CT scan, which can provide a more accurate measurement of the aneurysm’s size and shape.
Treatment for abdominal aneurysm depends on its size and location and if there are symptoms.