Context

Ultrasound is routinely used for the screening and monitoring of aortic diameter, and a limited ultrasound scan can reliably record the presence of an AAA.

Approximately 90-95 % of abdominal aortic aneurysms (AAA) are confined to the infrarenal aorta. The risk of rupture within 5 years is 25 % at 5 cm diameter. AAA smaller than 5 cm have a 3 % risk of rupture over 10 years. In the acute setting an AAA is defined as a transverse aortic diameter greater than 3 cm.

The role of ultrasound is to detect an enlarged abdominal aorta at the earliest clinical opportunity. If a normal aorta is clearly seen along its full extent then an aortic aneurysm can be excluded [1].

However, it must always be borne in mind that there are other, more rare aneurysms, e.g. splenic artery.

Learning bite

While AAA is the most common intra-abdominal aneurysm, the splenic artery may also become aneurysmal and may rupture.