Geometric, hemodynamic, and pathological study of a distal internal carotid artery aneurysm model in dogs.

BACKGROUND AND PURPOSE We created a distal internal carotid artery side-wall aneurysm model in dogs and compared its geometric, hemodynamic, and histological similarities with human models. METHODS Eight distal internal carotid artery-shaped devices were constructed using rapid prototyping, and 8 aneurysms were created via surgical reconstruction and elastase incubation. The geometric and hemodynamic parameters of the aneurysm and the parent artery of the dog and human models were compared, and histological response was evaluated at 12 weeks. RESULTS Eight aneurysms were successfully created with good geometric simulation of the arteries between the dog and human models. Hemodynamic analysis revealed similar changes in the hemodynamic parameters both in the aneurysm sac and in the parent artery of the dog and human models. Histological analysis revealed internal elastic lamina discontinuity, elastic fiber disruption, a thinner muscular layer, increased smooth muscle cell proliferation rate, increased inflammation cell infiltration, and higher matrix metalloproteinase-2 and matrix metalloproteinase-9 expression indices in the medial aneurysm wall. CONCLUSIONS The distal internal carotid artery aneurysm model in dogs is feasible and exhibited considerable geometric, hemodynamic, and histological similarities with the original human models.