EMBOLIZATION OF EXPERIMENTALLY CREATED ANEURYSMS WITH INTRAVASCULAR STENT DEVICES

PURPOSE: To assess the effectiveness of self-expanding, cobalt-alloy s tents in the treatment of aneurysms in a canine model and to observe t he pattern of blood flow and formation of fibrotic scar tissue. METHOD S: Porous metallic stents were endovascularly placed across the necks of experimentally created side aneurysms in the carotid arteries of th ree dogs; aneurysms were also created in the opposite carotid arteries in these animals to serve as controls. RESULTS: Before stent placemen t, angiography of the carotid arteries demonstrated whirl-like, vortex flow of blood within the lumens of the aneurysms. Inflow was seen alo ng the distal aneurysm wall; outflow was demonstrated along the proxim al wall; slower vortex flow was present in the central lumen. Immediat ely after stent placement there was disruption of the usual vortex now with stasis of contrast media and blood within the lumen. Inflow and outflow patterns were no longer seen. Complete ablation of these aneur ysms was evident at follow-up angiographic studies-1 week, 1 month, an d 2 months after stent placement. The stented carotid arteries remaine d widely patent; control aneurysms and carotid arteries were patent an d unchanged. Histopathologic analysis revealed fibrotic reactive scar tissue completely filling the stented aneurysm pouches.CONCLUSION: Tre atment of selected intracranial aneurysms via an endovascular approach has merit and could supplant more invasive, risky, and costly surgica l procedures in some cases.