Because the mortality rate from ruptured aortic aneurysms is high, appropriate screening of high-risk persons would be useful. The prevalence of abdominal aortic aneurysms in first-degree relatives of patients who have undergone surgery for abdominal aneurysm has been high (up to 29 percent in some studies). It is not clear whether screening should be performed in all first-degree relatives or only in a target group. The precise role of risk factors such as hypertension, smoking, evidence of arteriosclerotic disease and peripheral arterial aneurysms as screening indications is also unclear. Salo and associates studied the prevalence of familial aortic abdominal aneurysms and the relationship between prevalence and patients' age and sex.

A total of 238 first-degree relatives of 112 patients who had undergone elective or emergency resection of an infrarenal abdominal aortic aneurysm underwent ultrasonography, along with 284 control subjects of the same age and sex distribution. All of the study subjects were over 50 years of age. The two groups did not differ in reported risk factors. Data were also obtained for three first-degree relatives who had already undergone surgery for treatment of an abdominal aortic aneurysm.

Using a 30-mm cutoff to identify an aneurysm, 11 abdominal aneurysms were noted among 241 first-degree relatives. Eight aneurysms were found on ultrasonography, and three patients had already undergone surgery. The prevalence of aneurysm findings in the study group differed significantly from that in the control group (4.6 versus 1.4 percent). All aneurysms occurred in brothers, making the prevalence of abdominal aortic aneurysm 10.8 percent among male first-degree relatives. When first-degree male relatives were stratified by age, the prevalence of aneurysm was 18 percent in those older than 60 years of age and 22 percent in those older than 65 years of age. Aortic dilatation (aortic diameter of 20 to 29 mm) was verified in 30 of the 241 first-degree relatives (16 men and 14 women). No control subjects had abdominal aortic dilatation.

The authors conclude that the prevalence of abdominal aortic aneurysm is significantly increased in men older than 60 years of age who are brothers of patients who have been surgically treated for aortic aneurysm. Ultrasound screening may help identify this population and allow diagnosis of abdominal aortic aneurysm before complications such as rupture occur. Further studies of outcome, cost and feasibility are recommended.