Aorta
Abdominal Aortic Aneursym (AAA)
Screening and management of unruptured aneurysms
The majority of patients who develop an abdominal aortic aneurysm (AAA) are asymptomatic. Given the high mortality associated with a ruptured AAA it is therefore beneficial to screen patients. Screening for an abdominal aortic aneurysm consists of a single abdominal ultrasound for males aged 65.
Screening outcome
| Aorta width |
Interpretation |
Action |
| < 3 cm |
Normal |
No further action |
| 3 - 4.4 cm |
Small aneurysm |
Rescan every 12 months |
| 4.5 - 5.4 cm |
Medium aneurysm |
Rescan every 3 months |
| ≥ 5.5cm |
Large aneurysm |
Refer within 2 weeks to vascular surgery for probable intervention |
| Only found in 1 per 1,000 screened patients |
|
|
Further management
Low rupture risk
- asymptomatic, aortic diameter < 5.5cm (i.e. small and medium aneurysms)
- abdominal US surveillance (on time-scales outlines above) and optimise cardiovascular risk factors (e.g. stop smoking)
High rupture risk
- symptomatic, aortic diameter >=5.5cm or rapidly enlarging (>1cm/year)
- refer within 2 weeks to vascular surgery for probable intervention
- treat with elective endovascular repair (EVAR) or open repair if unsuitable. In EVAR a stent is placed into the abdominal aorta via the femoral artery to prevent blood from collecting in the aneurysm. A complication of EVAR is an endo-leak, where the stent fails to exclude blood from the aneurysm, and usually presents without symptoms on routine follow-up.