The creation of an infrarenal aneurysm within the native abdominal aorta of swine.
BACKGROUND
Models of native abdominal aortic aneurysms (AAA) have been created in rodents using elastase and calcium chloride perfusion. These models, however, do not permit the evaluation of endovascular devices. This study describes the use of mechanical and enzymatic techniques to create native AAA in swine.


METHODS
Surgically exposed abdominal aortas of ten male Yorkshire swine (25-35 kg) were dilated, then perfused for 20 min with a 50-mL solution of elastase (30 units) and collagenase (8000 units). Serial magnetic resonance imaging (MRI) at 1, 3, and 6 wk was used to evaluate postoperative aortic diameter. Animals were euthanized at 24 h, 48 h and 1, 2, and 6 wk for histological evaluation.


RESULTS
MRI demonstrated an increase in mean aortic diameter by 73.3% +/- 30.2% (33.3-116.7%), which gradually increased postoperatively. Partial endothelial loss, mural neutrophil infiltrate, and elastin disruption were evident (1, 3, and 7 days). Smooth muscle cell attrition occurred within the inner tunica media (7 days). Collagen deposition, limited SMC repopulation and luminal reendothelialization appeared at 3-6 wk. Elastin injury persisted.


CONCLUSIONS
The creation of an infrarenal aneurysm is possible within the native aorta of swine. After aneurysm creation, progressive increase in aortic diameter was detectable. Further evaluation will be necessary to more completely characterize the nature and extent of elastase-induced porcine aortic aneurysmal degeneration.
Hynecek
Robert L
RL
Weill Medical College of Cornell University, New York, NY, USA.
DeRubertis
Brian G
BG
Trocciola
Susan M
SM
Zhang
Honglei
H
Prince
Martin R
MR
Ennis
Terri L
TL
Kent
K Craig
KC
Faries
Peter L
PL
D000818:Animals; D017544:Aortic Aneurysm, Abdominal / Q000139:chemically induced* / Q000473:pathology*; D002122:Calcium Chloride; D002404:Catheterization; D017364:Collagenases; D004195:Disease Models, Animal; D021621:Imaging, Three-Dimensional; D007668:Kidney / Q000098:blood supply; D008279:Magnetic Resonance Imaging; D008297:Male; D009131:Muscle, Smooth, Vascular / Q000473:pathology; D009504:Neutrophils / Q000473:pathology; D010196:Pancreatic Elastase; D034421:Sus scrofa; D017540:Tunica Media / Q000473:pathology
D010196:Pancreatic Elastase; D017364:Collagenases; D002122:Calcium Chloride