Assessing differences in growth and shape between symptomatic and asymptomatic abdominal aortic aneurysms.

Area of Science:

• Cardiovascular Research
• Medical Imaging Analysis
• Biomechanical Engineering

Background:

• Abdominal aortic aneurysm (AAA) rupture risk is traditionally linked to maximum diameter (Dmax).
• Dmax alone is insufficient for predicting AAA rupture due to complex morphology.
• This study investigates morphological and growth differences between asymptomatic AAA (aAAA) and symptomatic AAA (sAAA).

Purpose of the Study:

• To compare growth patterns and shape characteristics between asymptomatic and symptomatic AAAs.
• To identify potential predictors of AAA rupture beyond maximum diameter.
• To explore differences in volumetric changes and 3D-growth between aAAA and sAAA.

Main Methods:

• Utilized CT angiography (CTA) data from 55 patients (12 sAAA) between 2010-2023.
• Employed PRAEVAorta for aortic segmentation and 3D Slicer for manual review.
• Compared demographics, Dmax, AAA flow lumen (AFL), intraluminal thrombus (ILT) volume, shape, curvature, and 3D-growth between aAAA and sAAA groups, including matched pairs.

Main Results:

• sAAA patients were younger and less likely to be Caucasian or have hypertension than aAAA patients.
• No significant differences in Dmax, overall volume, AFL, or ILT volume were found between groups.
• sAAA exhibited greater increases in AAA volume and AFL volume over time, and significantly higher 3D-growth at the left lateral aneurysm neck.

Conclusions:

• Symptomatic AAAs demonstrate accelerated volumetric and 3D-growth dynamics compared to asymptomatic ones.
• These complex volumetric and growth parameters may offer superior predictive value for AAA rupture risk.
• Further large-scale studies are needed to validate these findings and elucidate underlying mechanisms.