Creation of saccular aneurysms in the rabbit: A model suitable for testingendovascular devices

OBJECTIVE. This study developed an animal model of intracranial aneurysms s uitable for evaluating emerging endovascular devices for aneurysmal therapy . We characterized the short-, medium-, and long-term attributes of this en dovascular technique for saccular aneurysmal creation in the rabbit. MATERIALS AND METHODS. The right common carotid artery was surgically expos ed in nine New Zealand white rabbits. Using endovascular techniques, we occ luded the origin of the right common carotid artery with a pliable balloon. Elastase was incubated endoluminally in the proximal common carotid artery above the balloon. The common carotid artery was ligated distally. Animals were studied angiographically and sacrificed at 2 weeks (n = 3), 10 weeks (n = 3), and 24 weeks (n = 3) after aneurysm creation. Histology was obtain ed. RESULTS. Saccular aneurysms formed in eight of the nine rabbits. The aneury sm projected from the apex of an approximately 90 degrees curve of the pare nt vessel, the brachiocephalic artery. Mean aneurysm diameter was 4.5 mm (S D, 1.2 mm), and mean height was 7.5 mm (SD, 1.6 mm). All samples showed thi nned elastic lamina and no evidence of inflammation. in four of eight aneur ysms, unorganized thrombus was present in the dome of the aneurysm. CONCLUSION. Arterial aneurysms with intact endothelium and deficient elasti c lamina were reliably created in an area of high shear stress in New Zeala nd white rabbits. Three of these aneurysms remained patent for at least 6 m onths. We found a simple procedure that can be readily applied to the testi ng of new endovascular devices for a reliable creation of aneurysms in rabb its.