Medical Management of abdominal aortic aneurysms (AAA)- Will it work?

Abdominal aortic aneurysm (AAA) is a potentially lethal disease process which is common (4-9%) but easily and inexpensively detected by ultrasound.1 The starting point for the medical management of AAA is early detection. Despite the high frequency of AAA in the elderly, routine screening has not been advocated. The reasons for this is that most (9/10) AAA detected in screening programs are small. Since less that one percent (1/10 of the 4-9% with AAA) of individuals screened have an aneurysm that will require treatment at the time of detection, screening is not considered cost-effective. In addition, this information may put the patient in a quandary as they are made aware that they have an asymptomatic but life-threatening problem for which no immediate therapy is recommended. If there were a safe medical treatment that could be initiated at the time of detection, this perspective on aneurysm screening would likely change drastically because all small aneurysms would then warrant immediate treatment. If aneurysm growth were slowed but not arrested, wouldn't that just delay surgery to a future date when the patient might be at higher risk for repair? The answer to this is "Maybe " and here is the reason that this question must be addressed in carefully controlled studies. If a medical treatment reduced the growth rate by 10-20%, then the delay prior to the time when intervention were required would not be very long. This strategy might put the patients at greater risk. On the other hand, consider the effects of 30-50 % inhibition of AAA growth. (Fig 1) Fig1- Click image to view larger version This figure shows the effect of reducing AAA growth rate by 30, 40 and 50%. As a group, AAA patients have a relatively high mortality from all causes (6-7%/year). Thus, a significant decrease in the growth rate means that many patient will die of other causes befor