GPAtlas🧭 When to offer screening (and when to suspect AAA)
An abdominal aortic aneurysm is a focal dilatation of the abdominal aorta to ≥ 3 cm, or to at least 1.5× its normal diameter.
• The infrarenal segment is involved in the majority of cases.
• Most aneurysms are entirely asymptomatic – usually detected through screening or found incidentally on imaging requested for another reason.
The clinical importance lies in rupture:
• There is a long, silent period of growth before an AAA bursts.
• Once it bursts, the internal bleeding is frequently fatal – up to half of those reaching hospital for emergency repair do not survive to discharge.
This long pre-symptomatic window is precisely why population screening works. The NHS AAA Screening Programme offers a single, painless abdominal ultrasound to men in the year they turn 65.
Risk-stratify by maximum aortic diameter, and never miss a rupture. Management is driven almost entirely by size and growth rate.
| Maximum AP diameter | Classification | Action |
|---|---|---|
| < 3.0 cm | Normal | Discharge – no surveillance |
| 3.0–4.4 cm | Small AAA | 12-monthly surveillance |
| 4.5–5.4 cm | Medium AAA | 3-monthly surveillance |
| ≥ 5.5 cm | Large AAA | Refer to vascular service within 2 weeks |
Raise suspicion in men over 65, particularly those with:
• A smoking history (the strongest modifiable risk factor).
• A family history of AAA.
• Hypertension or COPD.
• European family origin.
Men aged 66 and over who were never screened can self-refer to the programme.
Source: NICE NG156 · NHS AAA Screening Programme
🔒 Sign up free to read the full topic
You're viewing a free preview. Create a free account to unlock the rest.
Sign up free →Sample topics are open to everyone in the Free Sample Bundle.