Taming the Risks of Aneurysms, a Silent Killer

January 29th, 2010

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Dangerous medical conditions that can take the lives of patients with little advance warning are usually referred to as “silent killers”. Such health conditions are often difficult to detect because patients frequently experience no symptoms that would normally trigger a visit to their doctor. Once such a condition shows itself, however, immediate treatment is usually required to prevent significant disability or even death. One of many such silent killers is the aneurysm (aneurism).

When the wall of an artery or vein becomes weak, the blood pressure pushing on that weakened area can cause it to balloon over time and fill with blood. This is usually not an issue by itself, but will quickly become a life-threatening problem if the wall of the artery or vein ruptures and internal bleeding takes place. The greater the aneurysm has grown, the greater the risk is that it will rupture.

Ruptured aneurysms in the major blood vessels of the chest cavity, the stomach area or abdomen, the thighs and the brain are the most likely to be fatal. This is because significant blood loss can occur from ruptures in these areas of the body.

In Britain, more than 6000 people die annually from aneurysms in the chest and stomach. In Canada, the numbers are about 1000. In the US, stomach aneurysms kill 15000 people per year, while brain aneurysms kill roughly 17000 people.

In the population, aneurysms in the stomach area, called abdominal aortic aneurysms (AAA), are some of the most common affecting as much as 9% of men over 65. These aneurysms are most frequent for men who are 3.5 to 5 times more likely to have an aneurysm than women. For aneurysms in the chest area, men have 1.5 times the risk that women do of developing this type of aneurysm.

All that said, the risk of death and disability from an aneurysm is higher for women who develop them. For aneurysms in the brain, a study from the University of Michigan found that women have 1.7 times the risk of aneurysm rupture compared to men. For aneurysms in the stomach area, women have 1.4 times the risk of dying if the aneurysm is treated whether or not it has ruptured. When considering aneurysms in the chest area, women have 4 times the risk of aneurysm rupture than men.

Factors that increase the risk of developing an aneurysm include high cholesterol, high blood pressure, clogged arteries (atherosclerosis) and smoking. A previous aneurysm also means that a person has a higher risk of a subsequent aneurysm. As well, researchers at the University Hospital in Stockholm studying twins have found that genetic factors are important in the development of the condition.

In situations where an identical twin has developed an aneurysm in the stomach area, there is a 1 in 4 chance that the other twin will also develop the same type of aneurysm. This means that genetic factors increase the risk by as much as 71 times over those without the genetic factor. However, these numbers don’t indicate the risk of inheriting the genes related to the development of aneurysms.

Given the risks of death for those with the different types of aneurysm, there is good news in that preventative surgery and treatments are lowering the mortality rate. Researchers at Harvard Medical School have found that in the US, rates of stomach aneurysm rupture have been decreased by 32% between 1993 and 2005 due, in part, to preventative measures. Deaths from these aneurysm ruptures have also been reduced by 27%.

Also good news is that newer, less invasive forms of preventative surgery are not significantly reducing the lifespan of patients. Research from Uppsala University Hospital in Sweden has found that from 1987 to 2005, the risks of preventative aneurysm repair have decreased to the point where the life span of patients who undergo the surgery is “only marginally shorter” than the general population.

As well, research from the Imperial College in England has shown that the use of common cholesterol lowering drugs can cut the risk of stomach aneurysm ruptures in half. This is a fairly easy way of reducing personal risk.

However, the key to prevention of an aneurysm is early detection. Stomach aneurysms can be detected by a $50 ultrasound screening and since they are a very common type, this is fairly easy decision. Screening for aneurysms in the chest and head require more precise medical imaging and are more expensive as a result. Genetic testing is not yet available to assess an individual’s risk of aneurysm. However, if relatives have suffered from an aneurysm, it is a good idea to inform your doctor so they may decide whether or not to have you screened.

Are you at risk of aneurysm or do you have one? Please feel free to share your experiences with others.

Related Links

http://content.nejm.org/cgi/content/abstract/339/24/1725

http://www.jvascsurg.org/article/PIIS0741521497702684/fulltext

http://aje.oxfordjournals.org/cgi/content/full/154/3/236

http://www.surgery.usc.edu/divisions/vas/abdominalaorticaneurysm.html

http://www2.med.umich.edu/prmc/media/newsroom/details.cfm?ID=352

http://www.nlm.nih.gov/medlineplus/ency/article/001122.htm

http://www.healthnews.uc.edu/news/?/9053/

http://www.bmj.com/content/vol338/issue7710/press_release.dtl

http://www.ctv.ca/servlet/ArticleNews/story/CTVNews/20080905/abdominal_aneurysm_080905/20080905?hub=Health

http://bionews.zampbioworld.org/2009/02/23/17729