Abdominal Aortic Aneurysm Surveillance Chart
Abdominal Aortic Aneurysm (AAA) Surveillance Chart. All incidentally found aortic aneurysms should be referred to a vascular surgeon if the patient is a potential candidate for surgery.
The urgency of follow-up depends on the size of the aneurysm and whether or not there are associated symptoms.
Recommended Surveillance by Aneurysm Size
| Aortic Diameter | Action |
|---|---|
| < 2.5 cm | No follow-up required |
| 2.5 – 2.9 cm | Possible future aneurysm – consider repeat ultrasound in 5 years |
| 3.0 – 3.9 cm | Small aneurysm – repeat ultrasound in 12 months |
| 4.0 – 4.4 cm | Small aneurysm – repeat ultrasound in 6 months |
| 4.5 – 4.9 cm | Moderate aneurysm – repeat ultrasound in 3 months |
| ≥ 5.0 cm | Large aneurysm – urgent referral to vascular surgery |
Note: While the risk of rupture increases with size, there is no truly “safe” aneurysm size. Rupture risk is unpredictable, and elective repair should be considered before rupture occurs.
Indications for Surgical Referral
Elective repair decisions are based on:
- Aneurysm size:
- Males: AAA > 5.5 cm
- Females: AAA > 5.0 cm
- Rapid growth:
- 1.0 cm/year
- Symptoms:
- Abdominal or back pain/tenderness
- Distal embolization
- Patient factors:
- Suitability for surgery (age, comorbidities)
- Patient preferences
Absolute Annual Risk of Rupture
| AAA Diameter (cm) | Annual Rupture Risk |
|---|---|
| 3.0 – 3.9 | 0% |
| 4.0 – 4.9 | ~1% |
| 5.0 – 5.9 | 1–10% |
| 6.0 – 6.9 | 10–22% |
| > 7.0 | 30–50% |
References
Publications
- Robinson D, Mees B, Verhagen H, Chuen J. Aortic aneurysms – screening, surveillance and referral. Aust Fam Physician. 2013 Jun;42(6):364-9.
FOAMed
- Nickson C. Abdominal aortic aneurysm (AAA). LITFL
- Hartung MP. Abdominal CT: aortic aneurysm. LITFL
- Lobo V. POCUS: Abdominal aorta. LITFL
- Lam L. CT Case 084. LITFL
- Nazerian P. Aortic Dissection Detection Risk Score (ADD-RS). MDCalc
Fellowship Notes
Physician in training. German translator and lover of medical history.