Q1: What is the aorta?
A1: The aorta is the main artery of the body, arising from the base of the left ventricle of the heart. It supplies oxygenated blood to all arteries except the pulmonary artery (which carries blood to the lungs to be oxygenated). The aorta curves after cardiac takeoff and down the chest into the abdomen, where it divides into two smaller arteries. It is a large vessel, about one-inch in diameter, with thick, elastic walls to withstand the changes in pressure as the heartbeats.
Q2: What is an abdominal aortic aneurysm (AAA)?
A2: An abdominal aortic aneurysm is a weakness in the wall of the aorta in the abdomen that allows the aorta to balloon out as the pressure from the passing blood flow presses against it. The weakness is usually caused by the accumulation of fat deposits, an injury or a defect that was present at birth.
In the majority of cases, aneurysms grow gradually over a period of time, increasing by an average of only two to three millimeters each year. It can take nearly 10 to 15 years for an aneurysm to reach a size at which surgery is deemed necessary. At this time, the aneurysm measures 5-6 cm and is 1.5 its normal size. When the aneurysm reaches this size, the risk of rupture increases by 20 percent per year and the one-year survival rate for patients without surgery is estimated to be 50 percent.
Q3: What symptoms are associated with AAA?
A3: In most cases, a person with an abdominal aortic aneurysm has no symptoms until the artery walls become severely dilated and the aneurysm has grown to a dangerous size. At this time, a person may experience back pain. The first sign of rupture is usually characterized by extreme pain in the lower abdomen and back. The severe internal bleeding caused by a rupture is often fatal.
Q4: How prevalent is AAA in the United States?
A4: Abdominal aortic aneurysms are the 13th leading cause of death in the Untied States, accountable for the death of 15,000 Americans each year. Over the past 40 years, the prevalence of AAA has risen three-fold. Further, because people with the condition are typically asymptomatic, it is estimated that only 200,000 of the 1.5 million people with AAA are actually diagnosed.
Nearly 10 percent of all men over the age of 65 are likely to have some form of an aneurysm. White males over 55 years of age are most often affected by AAAs. Rates of AAA are also twice as high for white males as for black people and white women.
Q5: What is the standard treatment for AAA?
A5: For the past 40 years the standard treatment for AAA has remained relatively unchanged. The current treatment for abdominal aortic aneurysms is open abdominal repair, an effective treatment that carries risks similar to majority invasive surgery. During this procedure, a surgeon makes a large abdominal incision and the aorta is clamped above and below the aneurysm. The aorta is then opened, a surgical graft is sewn in at the damaged site and the aorta is closed over it.
The open surgery procedure can last anywhere from two to five hours and has a relatively high complication rate of 15 to 25 percent. Additionally, the average hospital stay is seven to twelve days, including time spent in the ICU. Patient recovery time can last as long as three months.
Recent clinical trials demonstrated the safety and efficacy of a new treatment modality in which a stent graft is inserted into the femoral artery (the artery in the upper thigh) to the aorta through a small incision in the upper leg. This minimally invasive approach to treating AAA in commonly referred to as endovascular repair.
