From the Guidelines
Saccular aortic aneurysms may require intervention at smaller sizes, typically around 5.5 cm or larger in diameter, but the decision to intervene must be informed by the patient's individual anatomy and risk factors, as evidenced by the 2024 ESC guidelines 1. The size of a saccular aortic aneurysm is a critical factor in determining the risk of rupture and the need for intervention. According to the 2022 ACC/AHA guideline for the diagnosis and management of aortic disease 1, saccular aneurysms are more likely to be symptomatic at smaller sizes than fusiform aneurysms. The guideline recommends elective repair of patients presenting with saccular AAA, although size guidance is lacking due to limited natural history data. Key factors to consider in managing saccular aortic aneurysms include:
- Maximum diameter: intervention is typically recommended at diameters ≥5.5 cm in men or ≥5.0 cm in women 1
- Growth rate: aneurysms growing more than 0.5 cm per year may warrant earlier intervention regardless of absolute size
- Patient anatomy and risk factors: including genetic conditions, family history of aortic dissection, and other comorbidities
- Symptomatic status: patients with symptomatic aneurysms may require more aggressive management Regular imaging surveillance is essential for monitoring aneurysm size and growth rate, typically with CT or MRI every 6-12 months depending on aneurysm size and growth rate 1. Management of smaller aneurysms not requiring immediate intervention includes blood pressure control using beta-blockers or angiotensin receptor blockers as first-line therapy. The decision to intervene must be individualized and based on the patient's specific risk factors and anatomy, as well as the latest guidelines and evidence-based recommendations 1.
From the Research
Size of Saccular Aortic Aneurysm
- The average maximum diameter of saccular aortic aneurysms (SAAs) was 5.0±1.6 cm, as reported in a study published in the Journal of Vascular Surgery 2.
- In repaired aneurysms, the mean diameter was 5.4±1.4 cm, while in unrepaired aneurysms, it was 4.4±1.1 cm (P<.001) 2.
- A case report of a 37-year-old woman with multiple saccular aneurysms of the infrarenal abdominal aorta did not provide specific information on the size of the aneurysms, but highlighted the risk of rupture associated with saccular aneurysms 3.
- A study published in the Journal of the American Heart Association found that the median diameter of saccular abdominal aortic aneurysms (AAAs) at operation for non-ruptured cases was 44.0 mm, which was significantly smaller than that of fusiform AAAs (51.0 mm) 4.
- The same study found that the median diameter of saccular AAAs at rupture was 55.6 mm, which was also significantly smaller than that of fusiform AAAs (68.0 mm) 4.
- A review of MDCT imaging features of unstable abdominal aortic aneurysms highlighted the importance of recognizing imaging features that may herald instability and portend a higher chance of rupture, including saccular outpouching 5.
- A study published in the Journal of Vascular Surgery found that repairs of aneurysms below diameter recommendations (defined as <5.5 cm in men and <5.0 cm in women) accounted for approximately one-third of all elective AAA procedures, and that saccular morphology was one of the indications for repair below size recommendations 6.