A reproducible swine model of a surgically created saccular thoracic aortic aneurysm

摘要

A reproducible swine thoracic aortic aneurysm (TAA) model is useful for investigating new therapeutic interventions. We report a surgical method for creating areproducible swine saccular TAA model. We used eight female swine weighing 20–25 kg (LWD; ternary species). All procedures were performed under generalanesthesia and involved left thoracotomy. Following aortic cross-clamping, the thoracic aorta was surgically dissected and the media and intima were resected,and the dissection plane was extended by spreading the outer layer for aneurysmal space. Subsequently, only the adventitial layer of the aorta was sutured. At 2weeks after these procedures, angiography and computed tomography were performed. After follow-up imaging, the model animals were euthanized. Macroscopic,histological, and immunohistological examinations were performed. All model animals survived, and a saccular TAA was confirmed by follow-up imaging in allcases. The mean length of the shorter and the longer aortic diameter after the procedure were 14.01 ± 1.0 mm and 18.35 ± 1.4 mm, respectively(P<0.001). The rate of increase in the aortic diameter was 131.7 ± 13.8%, and the mean length of aneurysmal change at thoracic aorta was22.4 ± 1.9 mm. Histological examination revealed intimal tears and defects of elastic fibers in the media. Immunostaining revealed MMP-2 and MMP-9 expressionsat the aneurysm site. We report our surgical method for creating a swine saccular TAA model. Our model animal may be useful to investigate new therapeuticinterventions for aortic disease.