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Objective. Endovascular treatment of intracranial wide-necked aneurysms employing stentgrafts might constitute a promising alternative to established neurosurgical or endovascular treatment options. However, there is uncertainity concerning long-term vessel patency and biocompatibility of the covering material used for these stentgrafts. The objective of our study was, therefore, to evaluate in an animal model of wide necked aneurysms, which changes within the parent vessel wall are present after stentgraft placement using polyurethane as the covering material. Methods. Wide-necked aneurysms were created in rabbits by distal ligation and intraluminal incubation of the right common carotid artery with elastase. All 10 animals were treated with polyurethane covered stentgrafts. Angiography and histological analyses were performed including immunohistochemical investigations for estimating the proliferation of the intima and possible inflammatory infiltration of the vessel wall after one (n = 5) and three months (n = 5) observation. Results. Stentgrafts led to a complete and stable aneurysm occlusion in all but one animal in which the stent was initially misplaced. In one animal, the stentgraft was completely occluded as visible both at angiography and on histological examination. Here, old thrombus was found within the stent although the animal was on antiplatelet therapy. The other stentgrafts remained patent and demonstrated only minimal proliferative carrier vessel wall changes and no in-stent stenosis. Conclusions. In previous animal models using Dacron covered stentgrafts, a poor short term patency rate due to the limited biocompatibility was found. We found, that Polyurethane seemed to have less adverse effects upon the vessel wall. However, a longer follow-up period is necessary to exclude delayed stenosis of the parent vessels. Stentgrafts may, therefore, play a role in broad based aneurysms, dissecting aneurysms or pseudoaneurysms, however, vessel sacrifice using permanent balloon occlusion may be a safer and better established alternative compared to the use of stentgrafts. [ABSTRACT FROM AUTHOR]

Aneurysm configuration and neck morphology are important factors in the decision for cerebral aneurysm therapy, i.e., clipping versus coiling. The aim of our study was to create various aneurysm configurations in a predictable and reproducible way in an animal model. In our recently proposed endovascular approach to produce bifurcation aneurysms in the rabbit, the right common carotid artery (CCA) is surgically exposed and distally ligated, and a sheath is advanced retrogradely into the CCA, the base of which is proximally occluded using a Fogarty balloon. Subsequently, elastase is injected via a microcatheter that is placed directly distal to the balloon and allowed to incubate for 20 min. After removal of the sheath, saccular aneurysms begin to form within 2 weeks. For greater variability in aneurysm size and neck morphology, we modified two parameters of this formerly established elastase-induced aneurysm model—the distance between the balloon and sheath and the level of balloon position—before the elastase was endoluminally incubated in 15 rabbits. Three weeks after aneurysm induction, the size and configuration of the aneurysms were controlled using DSA. Our results confirm that balloon occlusion in the brachiocephalic trunk results in broad-based aneurysms, whereas balloon occlusion in the CCA gives rise to circumscribed aneurysm necks. By increasing the distance between the balloon and sheath, the rabbits developed significantly larger aneurysms. The balloon-sheath distance and the level of balloon occlusion proved to be parameters whose modifications result in predictable and reproducible aneurysm variants that can be used for the testing of endovascular devices. [ABSTRACT FROM AUTHOR]

Although Guglielmi detachable coil (GDC) systems have been generally accepted for treatment of intracranial aneurysms, primary stenting of aneurysms using porous stents or implantation of coils after stent placement remains experimental. Testing of these new methods requires an animal model which imitates human aneurysms in size, configuration and neck morphology. We assessed in detail the technical requirements of and steps for transfemoral stent treatment of experimentally induced aneurysms at the top of the brachiocephalic trunk in rabbits. We created aneurysms in ten rabbits by distal ligation and intraluminal digestion of the right common carotid artery with elastase. We treated five animals with porous stents alone, and five with stents plus coiling via the meshes of the stent, which permitted dense packing of coils. No complications related to the procedures occurred. In all animals, even in those treated solely with porous stents, total occlusion of the aneurysm was achieved. Our animal model can be suitable for testing the biocompatibility and occlusion rate of new methods and devices for the treatment of experimental aneurysms. [ABSTRACT FROM AUTHOR]