Selective screening for abdominal aortic aneurysm among patients referred to the vascular laboratory

Patients examined for peripheral arterial disease at the vascular laboratory, Uppsala University Hospital, are since 1993 screened for abdominal aortic aneurysm (AAA). The objective of this study was to study the prevalence of AAA found at this selective high-risk screening.

All files in the vascular laboratory were retrospectively reviewed. Of 9296 persons examined with arterial duplex between 1993 and October 2005, 5924 were screened for AAA. The primary target vessel was the carotid arteries in 3772 subjects, the renal arteries in 1529 subjects and the lower extremity arteries in 1457 subjects. An AAA was defined as an infrarenal aortic diameter >/=30mm.

179 subjects were found to have an AAA. In a logistic regression model male gender, age and duplex-verified arterial stenosis were independently associated with AAA (odds ratio 3.2, 2.0/20 years and 2.0, respectively, p<0.001). In men <60 years the AAA prevalence was 0.9% (95% confidence interval 0.2-1.6%) when arterial stenosis was absent and 1.5% (0.0-3.2%) when present. In men >/=60 years the AAA prevalence was 4.0% (3.0-5.1%) when no arterial stenosis was found and 7.3% (5.7-8.9%) when found. The corresponding prevalences in women were 0%, 0%, 1.2% (0.5-1.8%), and 3.1% (1.9-4.3%), respectively.

Men >/=60 years referred for arterial examination have a significant risk of having an AAA while only women >/=65 years with a duplex verified arterial stenosis have a sufficient risk of having an AAA. Studies to evaluate the benefit of selective high-risk screening are warranted.