A New Canine Carotid Artery Bifurcation Aneurysm Model for the Evaluation of Neurovascular Devices

Abstract

Stents are increasingly used for coiling of difficult aneurysms, to reduce the risk of recurrences, or to modify blood flow. Currently available bifurcation aneurysm models are ill-suited to assess stent performance before clinical use. We designed a new wide-neck canine T-type bifurcation aneurysm model. Its potential value as a training tool as well as in the evaluation of new techniques or embolic agents was assessed. Our first task was to verify that recurrences occurred after satisfactory coiling. A second aim of this preliminary work was to assess if the new model could recreate the technical challenges involved in bifurcation aneurysms. We introduce a new canine wide-neck bifurcation aneurysm model, created by using a vein pouch at the apex of an end-to-side anastomosis of the carotid arteries, with flow reversal in the proximal RCA by ligation of the innominate artery. Three aneurysms were treated with coil embolization, 10 were treated with stents (7 self-expandable, 3 balloon-expandable), and 3 were left untreated. Aneurysms were followed by duplex ultrasonography and angiography, and studied with macroscopic photography after euthanasia 11.8 +/- 3.9 months after surgery. All aneurysms remained patent at 9.0 +/- 3.6 months' follow-up. Coiling led to recurrences by 3 months in all 3 cases. Stent placement was technically difficult in all cases and did not lead to aneurysm thrombosis or neointimal closure of the aneurysm neck at 3 months. This model may be suitable for studying the effects of endovascular treatment on aneurysm and branch occlusion rates, for preclinical testing of stents and other intravascular devices, and for training students of endovascular technique.