Background: The aim of this study was to investigate the degree of penetration, permanence of occlusion and vascular changes induced by a newly modified mixture of n-butyl cyanoacrylate (Glubran 2®), ethanol, and Lipidol® (GEL) in endovascular treatment of experimental aneurysms induced in swine. Methods: Bilateral pouch aneurysms were created in the wall of the internal carotid artery in eighteen pigs. The sixteen aneurysms were treated with a new mixture of GEL with different component proportions. Angiograms were obtained at the time of treatment and at 1, 4, and 16 weeks after treatment. According to the scheduled experimental design, subjects were sacrificed at the time of treatment and 7, 30, and 90 days after embolization of experimentally induced aneurysms. The internal carotid artery and aneurysms were resected en bloc and fixed for histopathologic study. Results: All the experimentally induced aneurysms were completely occluded by the used mixture and remained occluded for the study period without recanalization. Histopathologic studies revealed the presence of an acute inflammatory reaction of aneurysm wall even after 7 days post embolization with focal angionecrosis, followed by a chronic inflammation which induced a thickening of the wall. Conclusions: The mixture succeeded to induce a complete occlusion which remained stable until 90 days post-embolization. After seven days from embolization, the mixture polymerization was associated with an acute inflammatory response followed by a connective tissue proliferation which induced a thickening of aneurysm walls.