Expansion rates of small abdominal aortic aneurysms

The present study was carried out in order to examine those factors that influence the rate of expansion of small abdominal aortic aneurysms.

A retrospective study was undertaken of 112 patients who attended the St George Vascular Laboratory between 1987 and 1997. These patients had abdominal aortic aneurysms that were considered to be too small to warrant surgical repair at the time of presentation. Sequential ultrasound examinations were used to measure maximal anteroposterior aneurysm diameter. From these data, annual growth rates were calculated. Growth rate per annum was then compared with gender, age, initial aortic aneurysm diameter, presence of hypertensive disease, cardiac disease, family history of aneurysmal disease, diabetes mellitus, smoking, beta-adrenergic blockade and lipid lowering drugs.

Univariate analysis showed that three factors were significantly related to growth rate: the initial size of the aortic aneurysm, the presence of cardiac disease and the presence of beta-adrenergic blockade.

The presence of beta-adrenergic blockade appeared to have an independent effect on aneurysm growth rate, and suggests a possible role for beta-adrenergic blockade as a therapeutic strategy in controlling expansion rates of small abdominal aortic aneurysms. A controlled double-blind clinical trial is required to demonstrate this conclusively.