Elastase-induced AAA model Model Definition Abdominal aortic aneurysm (AAA) is a common degenerative arterial disease, characterized by aneurysmal dilatation of the infrarenal abdominal aorta. It is defined as a focal dilatation of the abdominal aorta exceeding 1.5 times the normal diameter, or an aortic diameter ≥30 mm distal to the renal artery bifurcation. Risk factors for AAA include age, male gender, family history, smoking, chronic obstructive pulmonary disease, hyperlipidemia, and hypertension. The incidence of AAA is higher in males, with a male-to-female ratio reported to be approximately 4:1. AAA is usually asymptomatic before rupture, and overall mortality from ruptured AAA exceeds 80%. The major pathological changes of AAA include chronic inflammation, degradation of extracellular matrix, and apoptosis of vascular smooth muscle cells. Due to its complex and incompletely understood pathogenesis, AAA is widely considered to be associated with multiple factors such as genetic inheritance, inflammatory response, and extracellular matrix remodeling, involving immunology, molecular biology, and genomics. Therefore, the establishment of animal models is of great significance for studying the pathogenesis of AAA, exploring early diagnosis, and identifying effective therapeutic strategies.

Experimental Animals
Strain: Sprague–Dawley (SD) rats, Wistar rats
Age: 6–8 weeks
Sex: Not limited
Brief Modeling Method
The abdominal aortic aneurysm model is established by infusing porcine pancreatic elastase into the abdominal aorta.
Model Verification
After surgery, animals are euthanized and the diameter of the elastase-perfused aortic segment is measured. A diameter increase of more than 150% compared with the preoperative baseline indicates successful modeling.

Schematic diagram of elastase‑induced abdominal aortic aneurysm modeling

Abdominal aortic diameter measurement