Screening for abdominal aortic aneurysm: a single scan is enough.

A group of 223 men who were found to have a normal abdominal aortic diameter (less than 2.6 cm) at the age of 65 or 66 years when first examined by ultrasonography in 1988 was studied again 5 years later. Twenty-seven patients had died, none from confirmed aneurysm rupture, and repeat scans were obtained in 189 of the 196 survivors. A further patient was reassessed at laparotomy. Mean aortic diameter was unchanged during the intervening 5 years and 166 of 189 repeat scan measurements were within 3 mm of the original value. Only two patients were found to have an aortic diameter of 3 cm or more on rescanning. These results suggest that a single ultrasonographic examination at the age of 65 years can safely be used to exclude over 90 per cent of those examined from future risk of significant aneurysmal dilatation of the aorta, with important cost and organizational benefits for a population screening programme.