In medical terms, AAA does not refer to highly rated bonds or an Automobile Association. Most physicians recognize that “AAA” means Abdominal Aortic Aneurysm; a silent killer that is the 13th leading cause of death in this country.
Understanding the Definition of an Aneurysm
Today we are going to discuss the entity which lives on the arterial side of the circulation. We all know that arteries are the vascular structures that carry oxygen and nutrient rich blood to the tissues. When a vascular structure develops a focal dilation that is greater than 50% of its normal diameter, that dilation is called an aneurysm. It represents a weak spot in the vessel.
The aorta is the largest artery in your body. It runs from the heart down through the chest and then the abdomen giving off branches to the different tissues. When the abdominal aorta has an aneurysm it is logically called an abdominal aortic aneurysm (AAA) This is the most common place to find an aneurysm in humans.
Fusiform and Saccular Abdominal Aortic Aneurysm
As shown in the image above, AAA can be fusiform or saccular. It is estimated that about 2 million Americans, perhaps more, have an AAA. Many of those are undiagnosed. Over 200,000 cases are diagnosed each year. It is estimated that 3-10% of people over the age of 50 has an AAA.
So how do these aneurysms cause trouble? The main problem is that they can rupture. AAAs, like hernias, grow over time and become more dangerous and harder to fix. Unfortunately they are silent, usually causing no symptoms as they develop and grow. Most of them are discovered by accident and often the first indication of the presence of an AAA is the severe pain associated with rupture.
Are You at Risk of an AAA?
Because rupture is a catastrophic and life-threatening event, it is important to examine the factors that might indicate that you might be at risk for having an AAA. These are called risk factors and include: increasing age, nicotine use, high blood pressure, family history of AAA, male gender [males > female by 4-5x], and white race.
There is also a group of risk factors that make rupture more likely. These are: diameter [the most important factor], rapid expansion of > 0.6cm/yr in diameter, nicotine use, high blood pressure, eccentric shape and chronic obstructive pulmonary disease.
| Aneurysm Size (cm) | % Rupture Risk Per Year |
| < 4 | 0 |
| 4 – 5 | 0.5 – 5 (5) |
| 5 – 6 | 3 – 15 (10) |
| 6 – 7 | 10 – 20 (15) |
| 7 – 8 | 20 – 40 (30) |
| > 8 | 30 – 50 (40) |
The above table depicts the risk of rupture in %/yr. The numbers in () represent the average risk of rupture based on aneurysm diameter size. Rupture is to be avoided because the mortality rate is approximately 50% in several reported series. So, if an individual has the risk factors for aneurysm and/or rupture what is one to do if there are no symptoms to give warning?
In Part 2 of this series, we will discuss what you should do.
Dr. Robert W. Ruess of Five Star Vein Institute is a leader in the field of venous disorders. With locations in Las Vegas and Mesquite, NV, Five Star Vein Institute offers free vein screenings. Call to schedule your free screening today.